diff --git a/.gitignore b/.gitignore
index 4e17eaf..dc1ffac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,62 +1,10 @@
-# ---> CMake
-CMakeLists.txt.user
-CMakeCache.txt
-CMakeFiles
-CMakeScripts
-Testing
-Makefile
-cmake_install.cmake
-install_manifest.txt
-compile_commands.json
-CTestTestfile.cmake
-_deps
+# Ignore all
+*
+# Unignore all with extensions
+!*.*
+# Unignore all dirs
+!*/
 
-# ---> VisualStudioCode
-.vscode/*
-!.vscode/settings.json
-!.vscode/tasks.json
-!.vscode/launch.json
-!.vscode/extensions.json
-!.vscode/*.code-snippets
+*.dSYM/
 
-# Local History for Visual Studio Code
-.history/
-
-# Built Visual Studio Code Extensions
-*.vsix
-
-# ---> C++
-# Prerequisites
-*.d
-
-# Compiled Object files
-*.slo
-*.lo
-*.o
-*.obj
-
-# Precompiled Headers
-*.gch
-*.pch
-
-# Compiled Dynamic libraries
-*.so
-*.dylib
-*.dll
-
-# Fortran module files
-*.mod
-*.smod
-
-# Compiled Static libraries
-*.lai
-*.la
-*.a
-*.lib
-
-# Executables
-*.exe
-*.out
-*.app
-
-build
\ No newline at end of file
+build/
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..1e80bc4
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.10)
+project(hello_algo CXX)
+
+set(CMAKE_CXX_STANDARD 11)
+
+include_directories(./include)
+
+add_subdirectory(chapter_computational_complexity)
+add_subdirectory(chapter_array_and_linkedlist)
+add_subdirectory(chapter_stack_and_queue)
+add_subdirectory(chapter_hashing)
+add_subdirectory(chapter_tree)
+add_subdirectory(chapter_heap)
+add_subdirectory(chapter_graph)
+add_subdirectory(chapter_searching)
+add_subdirectory(chapter_sorting)
+add_subdirectory(chapter_divide_and_conquer)
+add_subdirectory(chapter_backtracking)
+add_subdirectory(chapter_dynamic_programming)
+add_subdirectory(chapter_greedy)
diff --git a/chapter_array_and_linkedlist/CMakeLists.txt b/chapter_array_and_linkedlist/CMakeLists.txt
new file mode 100644
index 0000000..2e933e0
--- /dev/null
+++ b/chapter_array_and_linkedlist/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_executable(array array.cpp)
+add_executable(linked_list linked_list.cpp)
+add_executable(list list.cpp)
+add_executable(my_list my_list.cpp)
diff --git a/chapter_array_and_linkedlist/array.cpp b/chapter_array_and_linkedlist/array.cpp
new file mode 100644
index 0000000..dd87b92
--- /dev/null
+++ b/chapter_array_and_linkedlist/array.cpp
@@ -0,0 +1,113 @@
+/**
+ * File: array.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 随机访问元素 */
+int randomAccess(int *nums, int size) {
+    // 在区间 [0, size) 中随机抽取一个数字
+    int randomIndex = rand() % size;
+    // 获取并返回随机元素
+    int randomNum = nums[randomIndex];
+    return randomNum;
+}
+
+/* 扩展数组长度 */
+int *extend(int *nums, int size, int enlarge) {
+    // 初始化一个扩展长度后的数组
+    int *res = new int[size + enlarge];
+    // 将原数组中的所有元素复制到新数组
+    for (int i = 0; i < size; i++) {
+        res[i] = nums[i];
+    }
+    // 释放内存
+    delete[] nums;
+    // 返回扩展后的新数组
+    return res;
+}
+
+/* 在数组的索引 index 处插入元素 num */
+void insert(int *nums, int size, int num, int index) {
+    // 把索引 index 以及之后的所有元素向后移动一位
+    for (int i = size - 1; i > index; i--) {
+        nums[i] = nums[i - 1];
+    }
+    // 将 num 赋给 index 处的元素
+    nums[index] = num;
+}
+
+/* 删除索引 index 处的元素 */
+void remove(int *nums, int size, int index) {
+    // 把索引 index 之后的所有元素向前移动一位
+    for (int i = index; i < size - 1; i++) {
+        nums[i] = nums[i + 1];
+    }
+}
+
+/* 遍历数组 */
+void traverse(int *nums, int size) {
+    int count = 0;
+    // 通过索引遍历数组
+    for (int i = 0; i < size; i++) {
+        count += nums[i];
+    }
+}
+
+/* 在数组中查找指定元素 */
+int find(int *nums, int size, int target) {
+    for (int i = 0; i < size; i++) {
+        if (nums[i] == target)
+            return i;
+    }
+    return -1;
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化数组 */
+    int size = 5;
+    int *arr = new int[size];
+    cout << "数组 arr = ";
+    printArray(arr, size);
+
+    int *nums = new int[size]{1, 3, 2, 5, 4};
+    cout << "数组 nums = ";
+    printArray(nums, size);
+
+    /* 随机访问 */
+    int randomNum = randomAccess(nums, size);
+    cout << "在 nums 中获取随机元素 " << randomNum << endl;
+
+    /* 长度扩展 */
+    int enlarge = 3;
+    nums = extend(nums, size, enlarge);
+    size += enlarge;
+    cout << "将数组长度扩展至 8 ，得到 nums = ";
+    printArray(nums, size);
+
+    /* 插入元素 */
+    insert(nums, size, 6, 3);
+    cout << "在索引 3 处插入数字 6 ，得到 nums = ";
+    printArray(nums, size);
+
+    /* 删除元素 */
+    remove(nums, size, 2);
+    cout << "删除索引 2 处的元素，得到 nums = ";
+    printArray(nums, size);
+
+    /* 遍历数组 */
+    traverse(nums, size);
+
+    /* 查找元素 */
+    int index = find(nums, size, 3);
+    cout << "在 nums 中查找元素 3 ，得到索引 = " << index << endl;
+
+    // 释放内存
+    delete[] arr;
+    delete[] nums;
+
+    return 0;
+}
diff --git a/chapter_array_and_linkedlist/linked_list.cpp b/chapter_array_and_linkedlist/linked_list.cpp
new file mode 100644
index 0000000..092226e
--- /dev/null
+++ b/chapter_array_and_linkedlist/linked_list.cpp
@@ -0,0 +1,89 @@
+/**
+ * File: linked_list.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 在链表的节点 n0 之后插入节点 P */
+void insert(ListNode *n0, ListNode *P) {
+    ListNode *n1 = n0->next;
+    P->next = n1;
+    n0->next = P;
+}
+
+/* 删除链表的节点 n0 之后的首个节点 */
+void remove(ListNode *n0) {
+    if (n0->next == nullptr)
+        return;
+    // n0 -> P -> n1
+    ListNode *P = n0->next;
+    ListNode *n1 = P->next;
+    n0->next = n1;
+    // 释放内存
+    delete P;
+}
+
+/* 访问链表中索引为 index 的节点 */
+ListNode *access(ListNode *head, int index) {
+    for (int i = 0; i < index; i++) {
+        if (head == nullptr)
+            return nullptr;
+        head = head->next;
+    }
+    return head;
+}
+
+/* 在链表中查找值为 target 的首个节点 */
+int find(ListNode *head, int target) {
+    int index = 0;
+    while (head != nullptr) {
+        if (head->val == target)
+            return index;
+        head = head->next;
+        index++;
+    }
+    return -1;
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化链表 */
+    // 初始化各个节点
+    ListNode *n0 = new ListNode(1);
+    ListNode *n1 = new ListNode(3);
+    ListNode *n2 = new ListNode(2);
+    ListNode *n3 = new ListNode(5);
+    ListNode *n4 = new ListNode(4);
+    // 构建节点之间的引用
+    n0->next = n1;
+    n1->next = n2;
+    n2->next = n3;
+    n3->next = n4;
+    cout << "初始化的链表为" << endl;
+    printLinkedList(n0);
+
+    /* 插入节点 */
+    insert(n0, new ListNode(0));
+    cout << "插入节点后的链表为" << endl;
+    printLinkedList(n0);
+
+    /* 删除节点 */
+    remove(n0);
+    cout << "删除节点后的链表为" << endl;
+    printLinkedList(n0);
+
+    /* 访问节点 */
+    ListNode *node = access(n0, 3);
+    cout << "链表中索引 3 处的节点的值 = " << node->val << endl;
+
+    /* 查找节点 */
+    int index = find(n0, 2);
+    cout << "链表中值为 2 的节点的索引 = " << index << endl;
+
+    // 释放内存
+    freeMemoryLinkedList(n0);
+
+    return 0;
+}
diff --git a/chapter_array_and_linkedlist/list.cpp b/chapter_array_and_linkedlist/list.cpp
new file mode 100644
index 0000000..e0502cc
--- /dev/null
+++ b/chapter_array_and_linkedlist/list.cpp
@@ -0,0 +1,72 @@
+/**
+ * File: list.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化列表 */
+    vector<int> nums = {1, 3, 2, 5, 4};
+    cout << "列表 nums = ";
+    printVector(nums);
+
+    /* 访问元素 */
+    int num = nums[1];
+    cout << "访问索引 1 处的元素，得到 num = " << num << endl;
+
+    /* 更新元素 */
+    nums[1] = 0;
+    cout << "将索引 1 处的元素更新为 0 ，得到 nums = ";
+    printVector(nums);
+
+    /* 清空列表 */
+    nums.clear();
+    cout << "清空列表后 nums = ";
+    printVector(nums);
+
+    /* 在尾部添加元素 */
+    nums.push_back(1);
+    nums.push_back(3);
+    nums.push_back(2);
+    nums.push_back(5);
+    nums.push_back(4);
+    cout << "添加元素后 nums = ";
+    printVector(nums);
+
+    /* 在中间插入元素 */
+    nums.insert(nums.begin() + 3, 6);
+    cout << "在索引 3 处插入数字 6 ，得到 nums = ";
+    printVector(nums);
+
+    /* 删除元素 */
+    nums.erase(nums.begin() + 3);
+    cout << "删除索引 3 处的元素，得到 nums = ";
+    printVector(nums);
+
+    /* 通过索引遍历列表 */
+    int count = 0;
+    for (int i = 0; i < nums.size(); i++) {
+        count += nums[i];
+    }
+    /* 直接遍历列表元素 */
+    count = 0;
+    for (int x : nums) {
+        count += x;
+    }
+
+    /* 拼接两个列表 */
+    vector<int> nums1 = {6, 8, 7, 10, 9};
+    nums.insert(nums.end(), nums1.begin(), nums1.end());
+    cout << "将列表 nums1 拼接到 nums 之后，得到 nums = ";
+    printVector(nums);
+
+    /* 排序列表 */
+    sort(nums.begin(), nums.end());
+    cout << "排序列表后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_array_and_linkedlist/my_list.cpp b/chapter_array_and_linkedlist/my_list.cpp
new file mode 100644
index 0000000..4fff94b
--- /dev/null
+++ b/chapter_array_and_linkedlist/my_list.cpp
@@ -0,0 +1,171 @@
+/**
+ * File: my_list.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 列表类 */
+class MyList {
+  private:
+    int *arr;             // 数组（存储列表元素）
+    int arrCapacity = 10; // 列表容量
+    int arrSize = 0;      // 列表长度（当前元素数量）
+    int extendRatio = 2;   // 每次列表扩容的倍数
+
+  public:
+    /* 构造方法 */
+    MyList() {
+        arr = new int[arrCapacity];
+    }
+
+    /* 析构方法 */
+    ~MyList() {
+        delete[] arr;
+    }
+
+    /* 获取列表长度（当前元素数量）*/
+    int size() {
+        return arrSize;
+    }
+
+    /* 获取列表容量 */
+    int capacity() {
+        return arrCapacity;
+    }
+
+    /* 访问元素 */
+    int get(int index) {
+        // 索引如果越界，则抛出异常，下同
+        if (index < 0 || index >= size())
+            throw out_of_range("索引越界");
+        return arr[index];
+    }
+
+    /* 更新元素 */
+    void set(int index, int num) {
+        if (index < 0 || index >= size())
+            throw out_of_range("索引越界");
+        arr[index] = num;
+    }
+
+    /* 在尾部添加元素 */
+    void add(int num) {
+        // 元素数量超出容量时，触发扩容机制
+        if (size() == capacity())
+            extendCapacity();
+        arr[size()] = num;
+        // 更新元素数量
+        arrSize++;
+    }
+
+    /* 在中间插入元素 */
+    void insert(int index, int num) {
+        if (index < 0 || index >= size())
+            throw out_of_range("索引越界");
+        // 元素数量超出容量时，触发扩容机制
+        if (size() == capacity())
+            extendCapacity();
+        // 将索引 index 以及之后的元素都向后移动一位
+        for (int j = size() - 1; j >= index; j--) {
+            arr[j + 1] = arr[j];
+        }
+        arr[index] = num;
+        // 更新元素数量
+        arrSize++;
+    }
+
+    /* 删除元素 */
+    int remove(int index) {
+        if (index < 0 || index >= size())
+            throw out_of_range("索引越界");
+        int num = arr[index];
+        // 将索引 index 之后的元素都向前移动一位
+        for (int j = index; j < size() - 1; j++) {
+            arr[j] = arr[j + 1];
+        }
+        // 更新元素数量
+        arrSize--;
+        // 返回被删除的元素
+        return num;
+    }
+
+    /* 列表扩容 */
+    void extendCapacity() {
+        // 新建一个长度为原数组 extendRatio 倍的新数组
+        int newCapacity = capacity() * extendRatio;
+        int *tmp = arr;
+        arr = new int[newCapacity];
+        // 将原数组中的所有元素复制到新数组
+        for (int i = 0; i < size(); i++) {
+            arr[i] = tmp[i];
+        }
+        // 释放内存
+        delete[] tmp;
+        arrCapacity = newCapacity;
+    }
+
+    /* 将列表转换为 Vector 用于打印 */
+    vector<int> toVector() {
+        // 仅转换有效长度范围内的列表元素
+        vector<int> vec(size());
+        for (int i = 0; i < size(); i++) {
+            vec[i] = arr[i];
+        }
+        return vec;
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化列表 */
+    MyList *nums = new MyList();
+    /* 在尾部添加元素 */
+    nums->add(1);
+    nums->add(3);
+    nums->add(2);
+    nums->add(5);
+    nums->add(4);
+    cout << "列表 nums = ";
+    vector<int> vec = nums->toVector();
+    printVector(vec);
+    cout << "容量 = " << nums->capacity() << " ，长度 = " << nums->size() << endl;
+
+    /* 在中间插入元素 */
+    nums->insert(3, 6);
+    cout << "在索引 3 处插入数字 6 ，得到 nums = ";
+    vec = nums->toVector();
+    printVector(vec);
+
+    /* 删除元素 */
+    nums->remove(3);
+    cout << "删除索引 3 处的元素，得到 nums = ";
+    vec = nums->toVector();
+    printVector(vec);
+
+    /* 访问元素 */
+    int num = nums->get(1);
+    cout << "访问索引 1 处的元素，得到 num = " << num << endl;
+
+    /* 更新元素 */
+    nums->set(1, 0);
+    cout << "将索引 1 处的元素更新为 0 ，得到 nums = ";
+    vec = nums->toVector();
+    printVector(vec);
+
+    /* 测试扩容机制 */
+    for (int i = 0; i < 10; i++) {
+        // 在 i = 5 时，列表长度将超出列表容量，此时触发扩容机制
+        nums->add(i);
+    }
+    cout << "扩容后的列表 nums = ";
+    vec = nums->toVector();
+    printVector(vec);
+    cout << "容量 = " << nums->capacity() << " ，长度 = " << nums->size() << endl;
+
+    // 释放内存
+    delete nums;
+
+    return 0;
+}
diff --git a/chapter_backtracking/CMakeLists.txt b/chapter_backtracking/CMakeLists.txt
new file mode 100644
index 0000000..6c271e3
--- /dev/null
+++ b/chapter_backtracking/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_executable(preorder_traversal_i_compact preorder_traversal_i_compact.cpp)
+add_executable(preorder_traversal_ii_compact preorder_traversal_ii_compact.cpp)
+add_executable(preorder_traversal_iii_compact preorder_traversal_iii_compact.cpp)
+add_executable(preorder_traversal_iii_template preorder_traversal_iii_template.cpp)
+add_executable(permutations_i permutations_i.cpp)
+add_executable(permutations_ii permutations_ii.cpp)
+add_executable(n_queens n_queens.cpp)
+add_executable(subset_sum_i_naive subset_sum_i_naive.cpp)
+add_executable(subset_sum_i subset_sum_i.cpp)
+add_executable(subset_sum_ii subset_sum_ii.cpp)
diff --git a/chapter_backtracking/n_queens.cpp b/chapter_backtracking/n_queens.cpp
new file mode 100644
index 0000000..9f759d7
--- /dev/null
+++ b/chapter_backtracking/n_queens.cpp
@@ -0,0 +1,65 @@
+/**
+ * File: n_queens.cpp
+ * Created Time: 2023-05-04
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 回溯算法：n 皇后 */
+void backtrack(int row, int n, vector<vector<string>> &state, vector<vector<vector<string>>> &res, vector<bool> &cols,
+               vector<bool> &diags1, vector<bool> &diags2) {
+    // 当放置完所有行时，记录解
+    if (row == n) {
+        res.push_back(state);
+        return;
+    }
+    // 遍历所有列
+    for (int col = 0; col < n; col++) {
+        // 计算该格子对应的主对角线和次对角线
+        int diag1 = row - col + n - 1;
+        int diag2 = row + col;
+        // 剪枝：不允许该格子所在列、主对角线、次对角线上存在皇后
+        if (!cols[col] && !diags1[diag1] && !diags2[diag2]) {
+            // 尝试：将皇后放置在该格子
+            state[row][col] = "Q";
+            cols[col] = diags1[diag1] = diags2[diag2] = true;
+            // 放置下一行
+            backtrack(row + 1, n, state, res, cols, diags1, diags2);
+            // 回退：将该格子恢复为空位
+            state[row][col] = "#";
+            cols[col] = diags1[diag1] = diags2[diag2] = false;
+        }
+    }
+}
+
+/* 求解 n 皇后 */
+vector<vector<vector<string>>> nQueens(int n) {
+    // 初始化 n*n 大小的棋盘，其中 'Q' 代表皇后，'#' 代表空位
+    vector<vector<string>> state(n, vector<string>(n, "#"));
+    vector<bool> cols(n, false);           // 记录列是否有皇后
+    vector<bool> diags1(2 * n - 1, false); // 记录主对角线上是否有皇后
+    vector<bool> diags2(2 * n - 1, false); // 记录次对角线上是否有皇后
+    vector<vector<vector<string>>> res;
+
+    backtrack(0, n, state, res, cols, diags1, diags2);
+
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    int n = 4;
+    vector<vector<vector<string>>> res = nQueens(n);
+
+    cout << "输入棋盘长宽为 " << n << endl;
+    cout << "皇后放置方案共有 " << res.size() << " 种" << endl;
+    for (const vector<vector<string>> &state : res) {
+        cout << "--------------------" << endl;
+        for (const vector<string> &row : state) {
+            printVector(row);
+        }
+    }
+
+    return 0;
+}
diff --git a/chapter_backtracking/permutations_i.cpp b/chapter_backtracking/permutations_i.cpp
new file mode 100644
index 0000000..a72fa6c
--- /dev/null
+++ b/chapter_backtracking/permutations_i.cpp
@@ -0,0 +1,54 @@
+/**
+ * File: permutations_i.cpp
+ * Created Time: 2023-04-24
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 回溯算法：全排列 I */
+void backtrack(vector<int> &state, const vector<int> &choices, vector<bool> &selected, vector<vector<int>> &res) {
+    // 当状态长度等于元素数量时，记录解
+    if (state.size() == choices.size()) {
+        res.push_back(state);
+        return;
+    }
+    // 遍历所有选择
+    for (int i = 0; i < choices.size(); i++) {
+        int choice = choices[i];
+        // 剪枝：不允许重复选择元素
+        if (!selected[i]) {
+            // 尝试：做出选择，更新状态
+            selected[i] = true;
+            state.push_back(choice);
+            // 进行下一轮选择
+            backtrack(state, choices, selected, res);
+            // 回退：撤销选择，恢复到之前的状态
+            selected[i] = false;
+            state.pop_back();
+        }
+    }
+}
+
+/* 全排列 I */
+vector<vector<int>> permutationsI(vector<int> nums) {
+    vector<int> state;
+    vector<bool> selected(nums.size(), false);
+    vector<vector<int>> res;
+    backtrack(state, nums, selected, res);
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {1, 2, 3};
+
+    vector<vector<int>> res = permutationsI(nums);
+
+    cout << "输入数组 nums = ";
+    printVector(nums);
+    cout << "所有排列 res = ";
+    printVectorMatrix(res);
+
+    return 0;
+}
diff --git a/chapter_backtracking/permutations_ii.cpp b/chapter_backtracking/permutations_ii.cpp
new file mode 100644
index 0000000..e3e3e7e
--- /dev/null
+++ b/chapter_backtracking/permutations_ii.cpp
@@ -0,0 +1,56 @@
+/**
+ * File: permutations_ii.cpp
+ * Created Time: 2023-04-24
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 回溯算法：全排列 II */
+void backtrack(vector<int> &state, const vector<int> &choices, vector<bool> &selected, vector<vector<int>> &res) {
+    // 当状态长度等于元素数量时，记录解
+    if (state.size() == choices.size()) {
+        res.push_back(state);
+        return;
+    }
+    // 遍历所有选择
+    unordered_set<int> duplicated;
+    for (int i = 0; i < choices.size(); i++) {
+        int choice = choices[i];
+        // 剪枝：不允许重复选择元素 且 不允许重复选择相等元素
+        if (!selected[i] && duplicated.find(choice) == duplicated.end()) {
+            // 尝试：做出选择，更新状态
+            duplicated.emplace(choice); // 记录选择过的元素值
+            selected[i] = true;
+            state.push_back(choice);
+            // 进行下一轮选择
+            backtrack(state, choices, selected, res);
+            // 回退：撤销选择，恢复到之前的状态
+            selected[i] = false;
+            state.pop_back();
+        }
+    }
+}
+
+/* 全排列 II */
+vector<vector<int>> permutationsII(vector<int> nums) {
+    vector<int> state;
+    vector<bool> selected(nums.size(), false);
+    vector<vector<int>> res;
+    backtrack(state, nums, selected, res);
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {1, 1, 2};
+
+    vector<vector<int>> res = permutationsII(nums);
+
+    cout << "输入数组 nums = ";
+    printVector(nums);
+    cout << "所有排列 res = ";
+    printVectorMatrix(res);
+
+    return 0;
+}
diff --git a/chapter_backtracking/preorder_traversal_i_compact.cpp b/chapter_backtracking/preorder_traversal_i_compact.cpp
new file mode 100644
index 0000000..d1d80bd
--- /dev/null
+++ b/chapter_backtracking/preorder_traversal_i_compact.cpp
@@ -0,0 +1,39 @@
+/**
+ * File: preorder_traversal_i_compact.cpp
+ * Created Time: 2023-04-16
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+vector<TreeNode *> res;
+
+/* 前序遍历：例题一 */
+void preOrder(TreeNode *root) {
+    if (root == nullptr) {
+        return;
+    }
+    if (root->val == 7) {
+        // 记录解
+        res.push_back(root);
+    }
+    preOrder(root->left);
+    preOrder(root->right);
+}
+
+/* Driver Code */
+int main() {
+    TreeNode *root = vectorToTree(vector<int>{1, 7, 3, 4, 5, 6, 7});
+    cout << "\n初始化二叉树" << endl;
+    printTree(root);
+
+    // 前序遍历
+    preOrder(root);
+
+    cout << "\n输出所有值为 7 的节点" << endl;
+    vector<int> vals;
+    for (TreeNode *node : res) {
+        vals.push_back(node->val);
+    }
+    printVector(vals);
+}
diff --git a/chapter_backtracking/preorder_traversal_ii_compact.cpp b/chapter_backtracking/preorder_traversal_ii_compact.cpp
new file mode 100644
index 0000000..3d75ae8
--- /dev/null
+++ b/chapter_backtracking/preorder_traversal_ii_compact.cpp
@@ -0,0 +1,46 @@
+/**
+ * File: preorder_traversal_ii_compact.cpp
+ * Created Time: 2023-04-16
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+vector<TreeNode *> path;
+vector<vector<TreeNode *>> res;
+
+/* 前序遍历：例题二 */
+void preOrder(TreeNode *root) {
+    if (root == nullptr) {
+        return;
+    }
+    // 尝试
+    path.push_back(root);
+    if (root->val == 7) {
+        // 记录解
+        res.push_back(path);
+    }
+    preOrder(root->left);
+    preOrder(root->right);
+    // 回退
+    path.pop_back();
+}
+
+/* Driver Code */
+int main() {
+    TreeNode *root = vectorToTree(vector<int>{1, 7, 3, 4, 5, 6, 7});
+    cout << "\n初始化二叉树" << endl;
+    printTree(root);
+
+    // 前序遍历
+    preOrder(root);
+
+    cout << "\n输出所有根节点到节点 7 的路径" << endl;
+    for (vector<TreeNode *> &path : res) {
+        vector<int> vals;
+        for (TreeNode *node : path) {
+            vals.push_back(node->val);
+        }
+        printVector(vals);
+    }
+}
diff --git a/chapter_backtracking/preorder_traversal_iii_compact.cpp b/chapter_backtracking/preorder_traversal_iii_compact.cpp
new file mode 100644
index 0000000..28a73bd
--- /dev/null
+++ b/chapter_backtracking/preorder_traversal_iii_compact.cpp
@@ -0,0 +1,47 @@
+/**
+ * File: preorder_traversal_iii_compact.cpp
+ * Created Time: 2023-04-16
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+vector<TreeNode *> path;
+vector<vector<TreeNode *>> res;
+
+/* 前序遍历：例题三 */
+void preOrder(TreeNode *root) {
+    // 剪枝
+    if (root == nullptr || root->val == 3) {
+        return;
+    }
+    // 尝试
+    path.push_back(root);
+    if (root->val == 7) {
+        // 记录解
+        res.push_back(path);
+    }
+    preOrder(root->left);
+    preOrder(root->right);
+    // 回退
+    path.pop_back();
+}
+
+/* Driver Code */
+int main() {
+    TreeNode *root = vectorToTree(vector<int>{1, 7, 3, 4, 5, 6, 7});
+    cout << "\n初始化二叉树" << endl;
+    printTree(root);
+
+    // 前序遍历
+    preOrder(root);
+
+    cout << "\n输出所有根节点到节点 7 的路径，要求路径中不包含值为 3 的节点" << endl;
+    for (vector<TreeNode *> &path : res) {
+        vector<int> vals;
+        for (TreeNode *node : path) {
+            vals.push_back(node->val);
+        }
+        printVector(vals);
+    }
+}
diff --git a/chapter_backtracking/preorder_traversal_iii_template.cpp b/chapter_backtracking/preorder_traversal_iii_template.cpp
new file mode 100644
index 0000000..c48fb3d
--- /dev/null
+++ b/chapter_backtracking/preorder_traversal_iii_template.cpp
@@ -0,0 +1,76 @@
+/**
+ * File: preorder_traversal_iii_template.cpp
+ * Created Time: 2023-04-16
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 判断当前状态是否为解 */
+bool isSolution(vector<TreeNode *> &state) {
+    return !state.empty() && state.back()->val == 7;
+}
+
+/* 记录解 */
+void recordSolution(vector<TreeNode *> &state, vector<vector<TreeNode *>> &res) {
+    res.push_back(state);
+}
+
+/* 判断在当前状态下，该选择是否合法 */
+bool isValid(vector<TreeNode *> &state, TreeNode *choice) {
+    return choice != nullptr && choice->val != 3;
+}
+
+/* 更新状态 */
+void makeChoice(vector<TreeNode *> &state, TreeNode *choice) {
+    state.push_back(choice);
+}
+
+/* 恢复状态 */
+void undoChoice(vector<TreeNode *> &state, TreeNode *choice) {
+    state.pop_back();
+}
+
+/* 回溯算法：例题三 */
+void backtrack(vector<TreeNode *> &state, vector<TreeNode *> &choices, vector<vector<TreeNode *>> &res) {
+    // 检查是否为解
+    if (isSolution(state)) {
+        // 记录解
+        recordSolution(state, res);
+    }
+    // 遍历所有选择
+    for (TreeNode *choice : choices) {
+        // 剪枝：检查选择是否合法
+        if (isValid(state, choice)) {
+            // 尝试：做出选择，更新状态
+            makeChoice(state, choice);
+            // 进行下一轮选择
+            vector<TreeNode *> nextChoices{choice->left, choice->right};
+            backtrack(state, nextChoices, res);
+            // 回退：撤销选择，恢复到之前的状态
+            undoChoice(state, choice);
+        }
+    }
+}
+
+/* Driver Code */
+int main() {
+    TreeNode *root = vectorToTree(vector<int>{1, 7, 3, 4, 5, 6, 7});
+    cout << "\n初始化二叉树" << endl;
+    printTree(root);
+
+    // 回溯算法
+    vector<TreeNode *> state;
+    vector<TreeNode *> choices = {root};
+    vector<vector<TreeNode *>> res;
+    backtrack(state, choices, res);
+
+    cout << "\n输出所有根节点到节点 7 的路径，要求路径中不包含值为 3 的节点" << endl;
+    for (vector<TreeNode *> &path : res) {
+        vector<int> vals;
+        for (TreeNode *node : path) {
+            vals.push_back(node->val);
+        }
+        printVector(vals);
+    }
+}
diff --git a/chapter_backtracking/subset_sum_i.cpp b/chapter_backtracking/subset_sum_i.cpp
new file mode 100644
index 0000000..fe4999c
--- /dev/null
+++ b/chapter_backtracking/subset_sum_i.cpp
@@ -0,0 +1,57 @@
+/**
+ * File: subset_sum_i.cpp
+ * Created Time: 2023-06-21
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 回溯算法：子集和 I */
+void backtrack(vector<int> &state, int target, vector<int> &choices, int start, vector<vector<int>> &res) {
+    // 子集和等于 target 时，记录解
+    if (target == 0) {
+        res.push_back(state);
+        return;
+    }
+    // 遍历所有选择
+    // 剪枝二：从 start 开始遍历，避免生成重复子集
+    for (int i = start; i < choices.size(); i++) {
+        // 剪枝一：若子集和超过 target ，则直接结束循环
+        // 这是因为数组已排序，后边元素更大，子集和一定超过 target
+        if (target - choices[i] < 0) {
+            break;
+        }
+        // 尝试：做出选择，更新 target, start
+        state.push_back(choices[i]);
+        // 进行下一轮选择
+        backtrack(state, target - choices[i], choices, i, res);
+        // 回退：撤销选择，恢复到之前的状态
+        state.pop_back();
+    }
+}
+
+/* 求解子集和 I */
+vector<vector<int>> subsetSumI(vector<int> &nums, int target) {
+    vector<int> state;              // 状态（子集）
+    sort(nums.begin(), nums.end()); // 对 nums 进行排序
+    int start = 0;                  // 遍历起始点
+    vector<vector<int>> res;        // 结果列表（子集列表）
+    backtrack(state, target, nums, start, res);
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {3, 4, 5};
+    int target = 9;
+
+    vector<vector<int>> res = subsetSumI(nums, target);
+
+    cout << "输入数组 nums = ";
+    printVector(nums);
+    cout << "target = " << target << endl;
+    cout << "所有和等于 " << target << " 的子集 res = " << endl;
+    printVectorMatrix(res);
+
+    return 0;
+}
diff --git a/chapter_backtracking/subset_sum_i_naive.cpp b/chapter_backtracking/subset_sum_i_naive.cpp
new file mode 100644
index 0000000..64647bd
--- /dev/null
+++ b/chapter_backtracking/subset_sum_i_naive.cpp
@@ -0,0 +1,54 @@
+/**
+ * File: subset_sum_i_naive.cpp
+ * Created Time: 2023-06-21
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 回溯算法：子集和 I */
+void backtrack(vector<int> &state, int target, int total, vector<int> &choices, vector<vector<int>> &res) {
+    // 子集和等于 target 时，记录解
+    if (total == target) {
+        res.push_back(state);
+        return;
+    }
+    // 遍历所有选择
+    for (size_t i = 0; i < choices.size(); i++) {
+        // 剪枝：若子集和超过 target ，则跳过该选择
+        if (total + choices[i] > target) {
+            continue;
+        }
+        // 尝试：做出选择，更新元素和 total
+        state.push_back(choices[i]);
+        // 进行下一轮选择
+        backtrack(state, target, total + choices[i], choices, res);
+        // 回退：撤销选择，恢复到之前的状态
+        state.pop_back();
+    }
+}
+
+/* 求解子集和 I（包含重复子集） */
+vector<vector<int>> subsetSumINaive(vector<int> &nums, int target) {
+    vector<int> state;       // 状态（子集）
+    int total = 0;           // 子集和
+    vector<vector<int>> res; // 结果列表（子集列表）
+    backtrack(state, target, total, nums, res);
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {3, 4, 5};
+    int target = 9;
+
+    vector<vector<int>> res = subsetSumINaive(nums, target);
+
+    cout << "输入数组 nums = ";
+    printVector(nums);
+    cout << "target = " << target << endl;
+    cout << "所有和等于 " << target << " 的子集 res = " << endl;
+    printVectorMatrix(res);
+
+    return 0;
+}
diff --git a/chapter_backtracking/subset_sum_ii.cpp b/chapter_backtracking/subset_sum_ii.cpp
new file mode 100644
index 0000000..b233581
--- /dev/null
+++ b/chapter_backtracking/subset_sum_ii.cpp
@@ -0,0 +1,62 @@
+/**
+ * File: subset_sum_ii.cpp
+ * Created Time: 2023-06-21
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 回溯算法：子集和 II */
+void backtrack(vector<int> &state, int target, vector<int> &choices, int start, vector<vector<int>> &res) {
+    // 子集和等于 target 时，记录解
+    if (target == 0) {
+        res.push_back(state);
+        return;
+    }
+    // 遍历所有选择
+    // 剪枝二：从 start 开始遍历，避免生成重复子集
+    // 剪枝三：从 start 开始遍历，避免重复选择同一元素
+    for (int i = start; i < choices.size(); i++) {
+        // 剪枝一：若子集和超过 target ，则直接结束循环
+        // 这是因为数组已排序，后边元素更大，子集和一定超过 target
+        if (target - choices[i] < 0) {
+            break;
+        }
+        // 剪枝四：如果该元素与左边元素相等，说明该搜索分支重复，直接跳过
+        if (i > start && choices[i] == choices[i - 1]) {
+            continue;
+        }
+        // 尝试：做出选择，更新 target, start
+        state.push_back(choices[i]);
+        // 进行下一轮选择
+        backtrack(state, target - choices[i], choices, i + 1, res);
+        // 回退：撤销选择，恢复到之前的状态
+        state.pop_back();
+    }
+}
+
+/* 求解子集和 II */
+vector<vector<int>> subsetSumII(vector<int> &nums, int target) {
+    vector<int> state;              // 状态（子集）
+    sort(nums.begin(), nums.end()); // 对 nums 进行排序
+    int start = 0;                  // 遍历起始点
+    vector<vector<int>> res;        // 结果列表（子集列表）
+    backtrack(state, target, nums, start, res);
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {4, 4, 5};
+    int target = 9;
+
+    vector<vector<int>> res = subsetSumII(nums, target);
+
+    cout << "输入数组 nums = ";
+    printVector(nums);
+    cout << "target = " << target << endl;
+    cout << "所有和等于 " << target << " 的子集 res = " << endl;
+    printVectorMatrix(res);
+
+    return 0;
+}
diff --git a/chapter_computational_complexity/CMakeLists.txt b/chapter_computational_complexity/CMakeLists.txt
new file mode 100644
index 0000000..ea2845b
--- /dev/null
+++ b/chapter_computational_complexity/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_executable(iteration iteration.cpp)
+add_executable(recursion recursion.cpp)
+add_executable(space_complexity space_complexity.cpp)
+add_executable(time_complexity time_complexity.cpp)
+add_executable(worst_best_time_complexity worst_best_time_complexity.cpp)
\ No newline at end of file
diff --git a/chapter_computational_complexity/iteration.cpp b/chapter_computational_complexity/iteration.cpp
new file mode 100644
index 0000000..ef262b7
--- /dev/null
+++ b/chapter_computational_complexity/iteration.cpp
@@ -0,0 +1,76 @@
+/**
+ * File: iteration.cpp
+ * Created Time: 2023-08-24
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* for 循环 */
+int forLoop(int n) {
+    int res = 0;
+    // 循环求和 1, 2, ..., n-1, n
+    for (int i = 1; i <= n; ++i) {
+        res += i;
+    }
+    return res;
+}
+
+/* while 循环 */
+int whileLoop(int n) {
+    int res = 0;
+    int i = 1; // 初始化条件变量
+    // 循环求和 1, 2, ..., n-1, n
+    while (i <= n) {
+        res += i;
+        i++; // 更新条件变量
+    }
+    return res;
+}
+
+/* while 循环（两次更新） */
+int whileLoopII(int n) {
+    int res = 0;
+    int i = 1; // 初始化条件变量
+    // 循环求和 1, 4, 10, ...
+    while (i <= n) {
+        res += i;
+        // 更新条件变量
+        i++;
+        i *= 2;
+    }
+    return res;
+}
+
+/* 双层 for 循环 */
+string nestedForLoop(int n) {
+    ostringstream res;
+    // 循环 i = 1, 2, ..., n-1, n
+    for (int i = 1; i <= n; ++i) {
+        // 循环 j = 1, 2, ..., n-1, n
+        for (int j = 1; j <= n; ++j) {
+            res << "(" << i << ", " << j << "), ";
+        }
+    }
+    return res.str();
+}
+
+/* Driver Code */
+int main() {
+    int n = 5;
+    int res;
+
+    res = forLoop(n);
+    cout << "\nfor 循环的求和结果 res = " << res << endl;
+
+    res = whileLoop(n);
+    cout << "\nwhile 循环的求和结果 res = " << res << endl;
+
+    res = whileLoopII(n);
+    cout << "\nwhile 循环（两次更新）求和结果 res = " << res << endl;
+
+    string resStr = nestedForLoop(n);
+    cout << "\n双层 for 循环的遍历结果 " << resStr << endl;
+
+    return 0;
+}
diff --git a/chapter_computational_complexity/recursion.cpp b/chapter_computational_complexity/recursion.cpp
new file mode 100644
index 0000000..3781556
--- /dev/null
+++ b/chapter_computational_complexity/recursion.cpp
@@ -0,0 +1,78 @@
+/**
+ * File: recursion.cpp
+ * Created Time: 2023-08-24
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 递归 */
+int recur(int n) {
+    // 终止条件
+    if (n == 1)
+        return 1;
+    // 递：递归调用
+    int res = recur(n - 1);
+    // 归：返回结果
+    return n + res;
+}
+
+/* 使用迭代模拟递归 */
+int forLoopRecur(int n) {
+    // 使用一个显式的栈来模拟系统调用栈
+    stack<int> stack;
+    int res = 0;
+    // 递：递归调用
+    for (int i = n; i > 0; i--) {
+        // 通过“入栈操作”模拟“递”
+        stack.push(i);
+    }
+    // 归：返回结果
+    while (!stack.empty()) {
+        // 通过“出栈操作”模拟“归”
+        res += stack.top();
+        stack.pop();
+    }
+    // res = 1+2+3+...+n
+    return res;
+}
+
+/* 尾递归 */
+int tailRecur(int n, int res) {
+    // 终止条件
+    if (n == 0)
+        return res;
+    // 尾递归调用
+    return tailRecur(n - 1, res + n);
+}
+
+/* 斐波那契数列：递归 */
+int fib(int n) {
+    // 终止条件 f(1) = 0, f(2) = 1
+    if (n == 1 || n == 2)
+        return n - 1;
+    // 递归调用 f(n) = f(n-1) + f(n-2)
+    int res = fib(n - 1) + fib(n - 2);
+    // 返回结果 f(n)
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    int n = 5;
+    int res;
+
+    res = recur(n);
+    cout << "\n递归函数的求和结果 res = " << res << endl;
+
+    res = forLoopRecur(n);
+    cout << "\n使用迭代模拟递归求和结果 res = " << res << endl;
+
+    res = tailRecur(n, 0);
+    cout << "\n尾递归函数的求和结果 res = " << res << endl;
+
+    res = fib(n);
+    cout << "\n斐波那契数列的第 " << n << " 项为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_computational_complexity/space_complexity.cpp b/chapter_computational_complexity/space_complexity.cpp
new file mode 100644
index 0000000..a41e7e1
--- /dev/null
+++ b/chapter_computational_complexity/space_complexity.cpp
@@ -0,0 +1,107 @@
+/**
+ * File: space_complexity.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 函数 */
+int func() {
+    // 执行某些操作
+    return 0;
+}
+
+/* 常数阶 */
+void constant(int n) {
+    // 常量、变量、对象占用 O(1) 空间
+    const int a = 0;
+    int b = 0;
+    vector<int> nums(10000);
+    ListNode node(0);
+    // 循环中的变量占用 O(1) 空间
+    for (int i = 0; i < n; i++) {
+        int c = 0;
+    }
+    // 循环中的函数占用 O(1) 空间
+    for (int i = 0; i < n; i++) {
+        func();
+    }
+}
+
+/* 线性阶 */
+void linear(int n) {
+    // 长度为 n 的数组占用 O(n) 空间
+    vector<int> nums(n);
+    // 长度为 n 的列表占用 O(n) 空间
+    vector<ListNode> nodes;
+    for (int i = 0; i < n; i++) {
+        nodes.push_back(ListNode(i));
+    }
+    // 长度为 n 的哈希表占用 O(n) 空间
+    unordered_map<int, string> map;
+    for (int i = 0; i < n; i++) {
+        map[i] = to_string(i);
+    }
+}
+
+/* 线性阶（递归实现） */
+void linearRecur(int n) {
+    cout << "递归 n = " << n << endl;
+    if (n == 1)
+        return;
+    linearRecur(n - 1);
+}
+
+/* 平方阶 */
+void quadratic(int n) {
+    // 二维列表占用 O(n^2) 空间
+    vector<vector<int>> numMatrix;
+    for (int i = 0; i < n; i++) {
+        vector<int> tmp;
+        for (int j = 0; j < n; j++) {
+            tmp.push_back(0);
+        }
+        numMatrix.push_back(tmp);
+    }
+}
+
+/* 平方阶（递归实现） */
+int quadraticRecur(int n) {
+    if (n <= 0)
+        return 0;
+    vector<int> nums(n);
+    cout << "递归 n = " << n << " 中的 nums 长度 = " << nums.size() << endl;
+    return quadraticRecur(n - 1);
+}
+
+/* 指数阶（建立满二叉树） */
+TreeNode *buildTree(int n) {
+    if (n == 0)
+        return nullptr;
+    TreeNode *root = new TreeNode(0);
+    root->left = buildTree(n - 1);
+    root->right = buildTree(n - 1);
+    return root;
+}
+
+/* Driver Code */
+int main() {
+    int n = 5;
+    // 常数阶
+    constant(n);
+    // 线性阶
+    linear(n);
+    linearRecur(n);
+    // 平方阶
+    quadratic(n);
+    quadraticRecur(n);
+    // 指数阶
+    TreeNode *root = buildTree(n);
+    printTree(root);
+
+    // 释放内存
+    freeMemoryTree(root);
+
+    return 0;
+}
diff --git a/chapter_computational_complexity/time_complexity.cpp b/chapter_computational_complexity/time_complexity.cpp
new file mode 100644
index 0000000..845e62c
--- /dev/null
+++ b/chapter_computational_complexity/time_complexity.cpp
@@ -0,0 +1,168 @@
+/**
+ * File: time_complexity.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 常数阶 */
+int constant(int n) {
+    int count = 0;
+    int size = 100000;
+    for (int i = 0; i < size; i++)
+        count++;
+    return count;
+}
+
+/* 线性阶 */
+int linear(int n) {
+    int count = 0;
+    for (int i = 0; i < n; i++)
+        count++;
+    return count;
+}
+
+/* 线性阶（遍历数组） */
+int arrayTraversal(vector<int> &nums) {
+    int count = 0;
+    // 循环次数与数组长度成正比
+    for (int num : nums) {
+        count++;
+    }
+    return count;
+}
+
+/* 平方阶 */
+int quadratic(int n) {
+    int count = 0;
+    // 循环次数与数组长度成平方关系
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < n; j++) {
+            count++;
+        }
+    }
+    return count;
+}
+
+/* 平方阶（冒泡排序） */
+int bubbleSort(vector<int> &nums) {
+    int count = 0; // 计数器
+    // 外循环：未排序区间为 [0, i]
+    for (int i = nums.size() - 1; i > 0; i--) {
+        // 内循环：将未排序区间 [0, i] 中的最大元素交换至该区间的最右端
+        for (int j = 0; j < i; j++) {
+            if (nums[j] > nums[j + 1]) {
+                // 交换 nums[j] 与 nums[j + 1]
+                int tmp = nums[j];
+                nums[j] = nums[j + 1];
+                nums[j + 1] = tmp;
+                count += 3; // 元素交换包含 3 个单元操作
+            }
+        }
+    }
+    return count;
+}
+
+/* 指数阶（循环实现） */
+int exponential(int n) {
+    int count = 0, base = 1;
+    // 细胞每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1)
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < base; j++) {
+            count++;
+        }
+        base *= 2;
+    }
+    // count = 1 + 2 + 4 + 8 + .. + 2^(n-1) = 2^n - 1
+    return count;
+}
+
+/* 指数阶（递归实现） */
+int expRecur(int n) {
+    if (n == 1)
+        return 1;
+    return expRecur(n - 1) + expRecur(n - 1) + 1;
+}
+
+/* 对数阶（循环实现） */
+int logarithmic(float n) {
+    int count = 0;
+    while (n > 1) {
+        n = n / 2;
+        count++;
+    }
+    return count;
+}
+
+/* 对数阶（递归实现） */
+int logRecur(float n) {
+    if (n <= 1)
+        return 0;
+    return logRecur(n / 2) + 1;
+}
+
+/* 线性对数阶 */
+int linearLogRecur(float n) {
+    if (n <= 1)
+        return 1;
+    int count = linearLogRecur(n / 2) + linearLogRecur(n / 2);
+    for (int i = 0; i < n; i++) {
+        count++;
+    }
+    return count;
+}
+
+/* 阶乘阶（递归实现） */
+int factorialRecur(int n) {
+    if (n == 0)
+        return 1;
+    int count = 0;
+    // 从 1 个分裂出 n 个
+    for (int i = 0; i < n; i++) {
+        count += factorialRecur(n - 1);
+    }
+    return count;
+}
+
+/* Driver Code */
+int main() {
+    // 可以修改 n 运行，体会一下各种复杂度的操作数量变化趋势
+    int n = 8;
+    cout << "输入数据大小 n = " << n << endl;
+
+    int count = constant(n);
+    cout << "常数阶的操作数量 = " << count << endl;
+
+    count = linear(n);
+    cout << "线性阶的操作数量 = " << count << endl;
+    vector<int> arr(n);
+    count = arrayTraversal(arr);
+    cout << "线性阶（遍历数组）的操作数量 = " << count << endl;
+
+    count = quadratic(n);
+    cout << "平方阶的操作数量 = " << count << endl;
+    vector<int> nums(n);
+    for (int i = 0; i < n; i++)
+        nums[i] = n - i; // [n,n-1,...,2,1]
+    count = bubbleSort(nums);
+    cout << "平方阶（冒泡排序）的操作数量 = " << count << endl;
+
+    count = exponential(n);
+    cout << "指数阶（循环实现）的操作数量 = " << count << endl;
+    count = expRecur(n);
+    cout << "指数阶（递归实现）的操作数量 = " << count << endl;
+
+    count = logarithmic((float)n);
+    cout << "对数阶（循环实现）的操作数量 = " << count << endl;
+    count = logRecur((float)n);
+    cout << "对数阶（递归实现）的操作数量 = " << count << endl;
+
+    count = linearLogRecur((float)n);
+    cout << "线性对数阶（递归实现）的操作数量 = " << count << endl;
+
+    count = factorialRecur(n);
+    cout << "阶乘阶（递归实现）的操作数量 = " << count << endl;
+
+    return 0;
+}
diff --git a/chapter_computational_complexity/worst_best_time_complexity.cpp b/chapter_computational_complexity/worst_best_time_complexity.cpp
new file mode 100644
index 0000000..f2ce76b
--- /dev/null
+++ b/chapter_computational_complexity/worst_best_time_complexity.cpp
@@ -0,0 +1,45 @@
+/**
+ * File: worst_best_time_complexity.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 生成一个数组，元素为 { 1, 2, ..., n }，顺序被打乱 */
+vector<int> randomNumbers(int n) {
+    vector<int> nums(n);
+    // 生成数组 nums = { 1, 2, 3, ..., n }
+    for (int i = 0; i < n; i++) {
+        nums[i] = i + 1;
+    }
+    // 使用系统时间生成随机种子
+    unsigned seed = chrono::system_clock::now().time_since_epoch().count();
+    // 随机打乱数组元素
+    shuffle(nums.begin(), nums.end(), default_random_engine(seed));
+    return nums;
+}
+
+/* 查找数组 nums 中数字 1 所在索引 */
+int findOne(vector<int> &nums) {
+    for (int i = 0; i < nums.size(); i++) {
+        // 当元素 1 在数组头部时，达到最佳时间复杂度 O(1)
+        // 当元素 1 在数组尾部时，达到最差时间复杂度 O(n)
+        if (nums[i] == 1)
+            return i;
+    }
+    return -1;
+}
+
+/* Driver Code */
+int main() {
+    for (int i = 0; i < 1000; i++) {
+        int n = 100;
+        vector<int> nums = randomNumbers(n);
+        int index = findOne(nums);
+        cout << "\n数组 [ 1, 2, ..., n ] 被打乱后 = ";
+        printVector(nums);
+        cout << "数字 1 的索引为 " << index << endl;
+    }
+    return 0;
+}
diff --git a/chapter_divide_and_conquer/CMakeLists.txt b/chapter_divide_and_conquer/CMakeLists.txt
new file mode 100644
index 0000000..38dfff7
--- /dev/null
+++ b/chapter_divide_and_conquer/CMakeLists.txt
@@ -0,0 +1,3 @@
+add_executable(binary_search_recur binary_search_recur.cpp)
+add_executable(build_tree build_tree.cpp)
+add_executable(hanota hanota.cpp)
\ No newline at end of file
diff --git a/chapter_divide_and_conquer/binary_search_recur.cpp b/chapter_divide_and_conquer/binary_search_recur.cpp
new file mode 100644
index 0000000..5bb3b24
--- /dev/null
+++ b/chapter_divide_and_conquer/binary_search_recur.cpp
@@ -0,0 +1,46 @@
+/**
+ * File: binary_search_recur.cpp
+ * Created Time: 2023-07-17
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 二分查找：问题 f(i, j) */
+int dfs(vector<int> &nums, int target, int i, int j) {
+    // 若区间为空，代表无目标元素，则返回 -1
+    if (i > j) {
+        return -1;
+    }
+    // 计算中点索引 m
+    int m = (i + j) / 2;
+    if (nums[m] < target) {
+        // 递归子问题 f(m+1, j)
+        return dfs(nums, target, m + 1, j);
+    } else if (nums[m] > target) {
+        // 递归子问题 f(i, m-1)
+        return dfs(nums, target, i, m - 1);
+    } else {
+        // 找到目标元素，返回其索引
+        return m;
+    }
+}
+
+/* 二分查找 */
+int binarySearch(vector<int> &nums, int target) {
+    int n = nums.size();
+    // 求解问题 f(0, n-1)
+    return dfs(nums, target, 0, n - 1);
+}
+
+/* Driver Code */
+int main() {
+    int target = 6;
+    vector<int> nums = {1, 3, 6, 8, 12, 15, 23, 26, 31, 35};
+
+    // 二分查找（双闭区间）
+    int index = binarySearch(nums, target);
+    cout << "目标元素 6 的索引 = " << index << endl;
+
+    return 0;
+}
\ No newline at end of file
diff --git a/chapter_divide_and_conquer/build_tree.cpp b/chapter_divide_and_conquer/build_tree.cpp
new file mode 100644
index 0000000..ca5389e
--- /dev/null
+++ b/chapter_divide_and_conquer/build_tree.cpp
@@ -0,0 +1,51 @@
+/**
+ * File: build_tree.cpp
+ * Created Time: 2023-07-17
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 构建二叉树：分治 */
+TreeNode *dfs(vector<int> &preorder, unordered_map<int, int> &inorderMap, int i, int l, int r) {
+    // 子树区间为空时终止
+    if (r - l < 0)
+        return NULL;
+    // 初始化根节点
+    TreeNode *root = new TreeNode(preorder[i]);
+    // 查询 m ，从而划分左右子树
+    int m = inorderMap[preorder[i]];
+    // 子问题：构建左子树
+    root->left = dfs(preorder, inorderMap, i + 1, l, m - 1);
+    // 子问题：构建右子树
+    root->right = dfs(preorder, inorderMap, i + 1 + m - l, m + 1, r);
+    // 返回根节点
+    return root;
+}
+
+/* 构建二叉树 */
+TreeNode *buildTree(vector<int> &preorder, vector<int> &inorder) {
+    // 初始化哈希表，存储 inorder 元素到索引的映射
+    unordered_map<int, int> inorderMap;
+    for (int i = 0; i < inorder.size(); i++) {
+        inorderMap[inorder[i]] = i;
+    }
+    TreeNode *root = dfs(preorder, inorderMap, 0, 0, inorder.size() - 1);
+    return root;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> preorder = {3, 9, 2, 1, 7};
+    vector<int> inorder = {9, 3, 1, 2, 7};
+    cout << "前序遍历 = ";
+    printVector(preorder);
+    cout << "中序遍历 = ";
+    printVector(inorder);
+
+    TreeNode *root = buildTree(preorder, inorder);
+    cout << "构建的二叉树为：\n";
+    printTree(root);
+
+    return 0;
+}
diff --git a/chapter_divide_and_conquer/hanota.cpp b/chapter_divide_and_conquer/hanota.cpp
new file mode 100644
index 0000000..7a2bc5a
--- /dev/null
+++ b/chapter_divide_and_conquer/hanota.cpp
@@ -0,0 +1,66 @@
+/**
+ * File: hanota.cpp
+ * Created Time: 2023-07-17
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 移动一个圆盘 */
+void move(vector<int> &src, vector<int> &tar) {
+    // 从 src 顶部拿出一个圆盘
+    int pan = src.back();
+    src.pop_back();
+    // 将圆盘放入 tar 顶部
+    tar.push_back(pan);
+}
+
+/* 求解汉诺塔问题 f(i) */
+void dfs(int i, vector<int> &src, vector<int> &buf, vector<int> &tar) {
+    // 若 src 只剩下一个圆盘，则直接将其移到 tar
+    if (i == 1) {
+        move(src, tar);
+        return;
+    }
+    // 子问题 f(i-1) ：将 src 顶部 i-1 个圆盘借助 tar 移到 buf
+    dfs(i - 1, src, tar, buf);
+    // 子问题 f(1) ：将 src 剩余一个圆盘移到 tar
+    move(src, tar);
+    // 子问题 f(i-1) ：将 buf 顶部 i-1 个圆盘借助 src 移到 tar
+    dfs(i - 1, buf, src, tar);
+}
+
+/* 求解汉诺塔问题 */
+void solveHanota(vector<int> &A, vector<int> &B, vector<int> &C) {
+    int n = A.size();
+    // 将 A 顶部 n 个圆盘借助 B 移到 C
+    dfs(n, A, B, C);
+}
+
+/* Driver Code */
+int main() {
+    // 列表尾部是柱子顶部
+    vector<int> A = {5, 4, 3, 2, 1};
+    vector<int> B = {};
+    vector<int> C = {};
+
+    cout << "初始状态下：\n";
+    cout << "A =";
+    printVector(A);
+    cout << "B =";
+    printVector(B);
+    cout << "C =";
+    printVector(C);
+
+    solveHanota(A, B, C);
+
+    cout << "圆盘移动完成后：\n";
+    cout << "A =";
+    printVector(A);
+    cout << "B =";
+    printVector(B);
+    cout << "C =";
+    printVector(C);
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/CMakeLists.txt b/chapter_dynamic_programming/CMakeLists.txt
new file mode 100644
index 0000000..ed18545
--- /dev/null
+++ b/chapter_dynamic_programming/CMakeLists.txt
@@ -0,0 +1,10 @@
+add_executable(climbing_stairs_backtrack climbing_stairs_backtrack.cpp)
+add_executable(climbing_stairs_dfs climbing_stairs_dfs.cpp)
+add_executable(climbing_stairs_dfs_mem climbing_stairs_dfs_mem.cpp)
+add_executable(climbing_stairs_dp climbing_stairs_dp.cpp)
+add_executable(min_cost_climbing_stairs_dp min_cost_climbing_stairs_dp.cpp)
+add_executable(min_path_sum min_path_sum.cpp)
+add_executable(unbounded_knapsack unbounded_knapsack.cpp)
+add_executable(coin_change coin_change.cpp)
+add_executable(coin_change_ii coin_change_ii.cpp)
+add_executable(edit_distance edit_distance.cpp)
\ No newline at end of file
diff --git a/chapter_dynamic_programming/climbing_stairs_backtrack.cpp b/chapter_dynamic_programming/climbing_stairs_backtrack.cpp
new file mode 100644
index 0000000..4080f28
--- /dev/null
+++ b/chapter_dynamic_programming/climbing_stairs_backtrack.cpp
@@ -0,0 +1,43 @@
+
+/**
+ * File: climbing_stairs_backtrack.cpp
+ * Created Time: 2023-06-30
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 回溯 */
+void backtrack(vector<int> &choices, int state, int n, vector<int> &res) {
+    // 当爬到第 n 阶时，方案数量加 1
+    if (state == n)
+        res[0]++;
+    // 遍历所有选择
+    for (auto &choice : choices) {
+        // 剪枝：不允许越过第 n 阶
+        if (state + choice > n)
+            continue;
+        // 尝试：做出选择，更新状态
+        backtrack(choices, state + choice, n, res);
+        // 回退
+    }
+}
+
+/* 爬楼梯：回溯 */
+int climbingStairsBacktrack(int n) {
+    vector<int> choices = {1, 2}; // 可选择向上爬 1 阶或 2 阶
+    int state = 0;                // 从第 0 阶开始爬
+    vector<int> res = {0};        // 使用 res[0] 记录方案数量
+    backtrack(choices, state, n, res);
+    return res[0];
+}
+
+/* Driver Code */
+int main() {
+    int n = 9;
+
+    int res = climbingStairsBacktrack(n);
+    cout << "爬 " << n << " 阶楼梯共有 " << res << " 种方案" << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/climbing_stairs_constraint_dp.cpp b/chapter_dynamic_programming/climbing_stairs_constraint_dp.cpp
new file mode 100644
index 0000000..eb5fc75
--- /dev/null
+++ b/chapter_dynamic_programming/climbing_stairs_constraint_dp.cpp
@@ -0,0 +1,37 @@
+/**
+ * File: climbing_stairs_constraint_dp.cpp
+ * Created Time: 2023-07-01
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 带约束爬楼梯：动态规划 */
+int climbingStairsConstraintDP(int n) {
+    if (n == 1 || n == 2) {
+        return 1;
+    }
+    // 初始化 dp 表，用于存储子问题的解
+    vector<vector<int>> dp(n + 1, vector<int>(3, 0));
+    // 初始状态：预设最小子问题的解
+    dp[1][1] = 1;
+    dp[1][2] = 0;
+    dp[2][1] = 0;
+    dp[2][2] = 1;
+    // 状态转移：从较小子问题逐步求解较大子问题
+    for (int i = 3; i <= n; i++) {
+        dp[i][1] = dp[i - 1][2];
+        dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
+    }
+    return dp[n][1] + dp[n][2];
+}
+
+/* Driver Code */
+int main() {
+    int n = 9;
+
+    int res = climbingStairsConstraintDP(n);
+    cout << "爬 " << n << " 阶楼梯共有 " << res << " 种方案" << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/climbing_stairs_dfs.cpp b/chapter_dynamic_programming/climbing_stairs_dfs.cpp
new file mode 100644
index 0000000..ffcff18
--- /dev/null
+++ b/chapter_dynamic_programming/climbing_stairs_dfs.cpp
@@ -0,0 +1,32 @@
+/**
+ * File: climbing_stairs_dfs.cpp
+ * Created Time: 2023-06-30
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 搜索 */
+int dfs(int i) {
+    // 已知 dp[1] 和 dp[2] ，返回之
+    if (i == 1 || i == 2)
+        return i;
+    // dp[i] = dp[i-1] + dp[i-2]
+    int count = dfs(i - 1) + dfs(i - 2);
+    return count;
+}
+
+/* 爬楼梯：搜索 */
+int climbingStairsDFS(int n) {
+    return dfs(n);
+}
+
+/* Driver Code */
+int main() {
+    int n = 9;
+
+    int res = climbingStairsDFS(n);
+    cout << "爬 " << n << " 阶楼梯共有 " << res << " 种方案" << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/climbing_stairs_dfs_mem.cpp b/chapter_dynamic_programming/climbing_stairs_dfs_mem.cpp
new file mode 100644
index 0000000..7ae62cb
--- /dev/null
+++ b/chapter_dynamic_programming/climbing_stairs_dfs_mem.cpp
@@ -0,0 +1,39 @@
+/**
+ * File: climbing_stairs_dfs_mem.cpp
+ * Created Time: 2023-06-30
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 记忆化搜索 */
+int dfs(int i, vector<int> &mem) {
+    // 已知 dp[1] 和 dp[2] ，返回之
+    if (i == 1 || i == 2)
+        return i;
+    // 若存在记录 dp[i] ，则直接返回之
+    if (mem[i] != -1)
+        return mem[i];
+    // dp[i] = dp[i-1] + dp[i-2]
+    int count = dfs(i - 1, mem) + dfs(i - 2, mem);
+    // 记录 dp[i]
+    mem[i] = count;
+    return count;
+}
+
+/* 爬楼梯：记忆化搜索 */
+int climbingStairsDFSMem(int n) {
+    // mem[i] 记录爬到第 i 阶的方案总数，-1 代表无记录
+    vector<int> mem(n + 1, -1);
+    return dfs(n, mem);
+}
+
+/* Driver Code */
+int main() {
+    int n = 9;
+
+    int res = climbingStairsDFSMem(n);
+    cout << "爬 " << n << " 阶楼梯共有 " << res << " 种方案" << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/climbing_stairs_dp.cpp b/chapter_dynamic_programming/climbing_stairs_dp.cpp
new file mode 100644
index 0000000..ce822e4
--- /dev/null
+++ b/chapter_dynamic_programming/climbing_stairs_dp.cpp
@@ -0,0 +1,49 @@
+/**
+ * File: climbing_stairs_dp.cpp
+ * Created Time: 2023-06-30
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 爬楼梯：动态规划 */
+int climbingStairsDP(int n) {
+    if (n == 1 || n == 2)
+        return n;
+    // 初始化 dp 表，用于存储子问题的解
+    vector<int> dp(n + 1);
+    // 初始状态：预设最小子问题的解
+    dp[1] = 1;
+    dp[2] = 2;
+    // 状态转移：从较小子问题逐步求解较大子问题
+    for (int i = 3; i <= n; i++) {
+        dp[i] = dp[i - 1] + dp[i - 2];
+    }
+    return dp[n];
+}
+
+/* 爬楼梯：空间优化后的动态规划 */
+int climbingStairsDPComp(int n) {
+    if (n == 1 || n == 2)
+        return n;
+    int a = 1, b = 2;
+    for (int i = 3; i <= n; i++) {
+        int tmp = b;
+        b = a + b;
+        a = tmp;
+    }
+    return b;
+}
+
+/* Driver Code */
+int main() {
+    int n = 9;
+
+    int res = climbingStairsDP(n);
+    cout << "爬 " << n << " 阶楼梯共有 " << res << " 种方案" << endl;
+
+    res = climbingStairsDPComp(n);
+    cout << "爬 " << n << " 阶楼梯共有 " << res << " 种方案" << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/coin_change.cpp b/chapter_dynamic_programming/coin_change.cpp
new file mode 100644
index 0000000..c59b83a
--- /dev/null
+++ b/chapter_dynamic_programming/coin_change.cpp
@@ -0,0 +1,70 @@
+/**
+ * File: coin_change.cpp
+ * Created Time: 2023-07-11
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 零钱兑换：动态规划 */
+int coinChangeDP(vector<int> &coins, int amt) {
+    int n = coins.size();
+    int MAX = amt + 1;
+    // 初始化 dp 表
+    vector<vector<int>> dp(n + 1, vector<int>(amt + 1, 0));
+    // 状态转移：首行首列
+    for (int a = 1; a <= amt; a++) {
+        dp[0][a] = MAX;
+    }
+    // 状态转移：其余行和列
+    for (int i = 1; i <= n; i++) {
+        for (int a = 1; a <= amt; a++) {
+            if (coins[i - 1] > a) {
+                // 若超过目标金额，则不选硬币 i
+                dp[i][a] = dp[i - 1][a];
+            } else {
+                // 不选和选硬币 i 这两种方案的较小值
+                dp[i][a] = min(dp[i - 1][a], dp[i][a - coins[i - 1]] + 1);
+            }
+        }
+    }
+    return dp[n][amt] != MAX ? dp[n][amt] : -1;
+}
+
+/* 零钱兑换：空间优化后的动态规划 */
+int coinChangeDPComp(vector<int> &coins, int amt) {
+    int n = coins.size();
+    int MAX = amt + 1;
+    // 初始化 dp 表
+    vector<int> dp(amt + 1, MAX);
+    dp[0] = 0;
+    // 状态转移
+    for (int i = 1; i <= n; i++) {
+        for (int a = 1; a <= amt; a++) {
+            if (coins[i - 1] > a) {
+                // 若超过目标金额，则不选硬币 i
+                dp[a] = dp[a];
+            } else {
+                // 不选和选硬币 i 这两种方案的较小值
+                dp[a] = min(dp[a], dp[a - coins[i - 1]] + 1);
+            }
+        }
+    }
+    return dp[amt] != MAX ? dp[amt] : -1;
+}
+
+/* Driver code */
+int main() {
+    vector<int> coins = {1, 2, 5};
+    int amt = 4;
+
+    // 动态规划
+    int res = coinChangeDP(coins, amt);
+    cout << "凑到目标金额所需的最少硬币数量为 " << res << endl;
+
+    // 空间优化后的动态规划
+    res = coinChangeDPComp(coins, amt);
+    cout << "凑到目标金额所需的最少硬币数量为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/coin_change_ii.cpp b/chapter_dynamic_programming/coin_change_ii.cpp
new file mode 100644
index 0000000..7364074
--- /dev/null
+++ b/chapter_dynamic_programming/coin_change_ii.cpp
@@ -0,0 +1,68 @@
+/**
+ * File: coin_change_ii.cpp
+ * Created Time: 2023-07-11
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 零钱兑换 II：动态规划 */
+int coinChangeIIDP(vector<int> &coins, int amt) {
+    int n = coins.size();
+    // 初始化 dp 表
+    vector<vector<int>> dp(n + 1, vector<int>(amt + 1, 0));
+    // 初始化首列
+    for (int i = 0; i <= n; i++) {
+        dp[i][0] = 1;
+    }
+    // 状态转移
+    for (int i = 1; i <= n; i++) {
+        for (int a = 1; a <= amt; a++) {
+            if (coins[i - 1] > a) {
+                // 若超过目标金额，则不选硬币 i
+                dp[i][a] = dp[i - 1][a];
+            } else {
+                // 不选和选硬币 i 这两种方案之和
+                dp[i][a] = dp[i - 1][a] + dp[i][a - coins[i - 1]];
+            }
+        }
+    }
+    return dp[n][amt];
+}
+
+/* 零钱兑换 II：空间优化后的动态规划 */
+int coinChangeIIDPComp(vector<int> &coins, int amt) {
+    int n = coins.size();
+    // 初始化 dp 表
+    vector<int> dp(amt + 1, 0);
+    dp[0] = 1;
+    // 状态转移
+    for (int i = 1; i <= n; i++) {
+        for (int a = 1; a <= amt; a++) {
+            if (coins[i - 1] > a) {
+                // 若超过目标金额，则不选硬币 i
+                dp[a] = dp[a];
+            } else {
+                // 不选和选硬币 i 这两种方案之和
+                dp[a] = dp[a] + dp[a - coins[i - 1]];
+            }
+        }
+    }
+    return dp[amt];
+}
+
+/* Driver code */
+int main() {
+    vector<int> coins = {1, 2, 5};
+    int amt = 5;
+
+    // 动态规划
+    int res = coinChangeIIDP(coins, amt);
+    cout << "凑出目标金额的硬币组合数量为 " << res << endl;
+
+    // 空间优化后的动态规划
+    res = coinChangeIIDPComp(coins, amt);
+    cout << "凑出目标金额的硬币组合数量为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/edit_distance.cpp b/chapter_dynamic_programming/edit_distance.cpp
new file mode 100644
index 0000000..21a04b0
--- /dev/null
+++ b/chapter_dynamic_programming/edit_distance.cpp
@@ -0,0 +1,136 @@
+/**
+ * File: edit_distance.cpp
+ * Created Time: 2023-07-13
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 编辑距离：暴力搜索 */
+int editDistanceDFS(string s, string t, int i, int j) {
+    // 若 s 和 t 都为空，则返回 0
+    if (i == 0 && j == 0)
+        return 0;
+    // 若 s 为空，则返回 t 长度
+    if (i == 0)
+        return j;
+    // 若 t 为空，则返回 s 长度
+    if (j == 0)
+        return i;
+    // 若两字符相等，则直接跳过此两字符
+    if (s[i - 1] == t[j - 1])
+        return editDistanceDFS(s, t, i - 1, j - 1);
+    // 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
+    int insert = editDistanceDFS(s, t, i, j - 1);
+    int del = editDistanceDFS(s, t, i - 1, j);
+    int replace = editDistanceDFS(s, t, i - 1, j - 1);
+    // 返回最少编辑步数
+    return min(min(insert, del), replace) + 1;
+}
+
+/* 编辑距离：记忆化搜索 */
+int editDistanceDFSMem(string s, string t, vector<vector<int>> &mem, int i, int j) {
+    // 若 s 和 t 都为空，则返回 0
+    if (i == 0 && j == 0)
+        return 0;
+    // 若 s 为空，则返回 t 长度
+    if (i == 0)
+        return j;
+    // 若 t 为空，则返回 s 长度
+    if (j == 0)
+        return i;
+    // 若已有记录，则直接返回之
+    if (mem[i][j] != -1)
+        return mem[i][j];
+    // 若两字符相等，则直接跳过此两字符
+    if (s[i - 1] == t[j - 1])
+        return editDistanceDFSMem(s, t, mem, i - 1, j - 1);
+    // 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
+    int insert = editDistanceDFSMem(s, t, mem, i, j - 1);
+    int del = editDistanceDFSMem(s, t, mem, i - 1, j);
+    int replace = editDistanceDFSMem(s, t, mem, i - 1, j - 1);
+    // 记录并返回最少编辑步数
+    mem[i][j] = min(min(insert, del), replace) + 1;
+    return mem[i][j];
+}
+
+/* 编辑距离：动态规划 */
+int editDistanceDP(string s, string t) {
+    int n = s.length(), m = t.length();
+    vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
+    // 状态转移：首行首列
+    for (int i = 1; i <= n; i++) {
+        dp[i][0] = i;
+    }
+    for (int j = 1; j <= m; j++) {
+        dp[0][j] = j;
+    }
+    // 状态转移：其余行和列
+    for (int i = 1; i <= n; i++) {
+        for (int j = 1; j <= m; j++) {
+            if (s[i - 1] == t[j - 1]) {
+                // 若两字符相等，则直接跳过此两字符
+                dp[i][j] = dp[i - 1][j - 1];
+            } else {
+                // 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
+                dp[i][j] = min(min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1;
+            }
+        }
+    }
+    return dp[n][m];
+}
+
+/* 编辑距离：空间优化后的动态规划 */
+int editDistanceDPComp(string s, string t) {
+    int n = s.length(), m = t.length();
+    vector<int> dp(m + 1, 0);
+    // 状态转移：首行
+    for (int j = 1; j <= m; j++) {
+        dp[j] = j;
+    }
+    // 状态转移：其余行
+    for (int i = 1; i <= n; i++) {
+        // 状态转移：首列
+        int leftup = dp[0]; // 暂存 dp[i-1, j-1]
+        dp[0] = i;
+        // 状态转移：其余列
+        for (int j = 1; j <= m; j++) {
+            int temp = dp[j];
+            if (s[i - 1] == t[j - 1]) {
+                // 若两字符相等，则直接跳过此两字符
+                dp[j] = leftup;
+            } else {
+                // 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
+                dp[j] = min(min(dp[j - 1], dp[j]), leftup) + 1;
+            }
+            leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
+        }
+    }
+    return dp[m];
+}
+
+/* Driver Code */
+int main() {
+    string s = "bag";
+    string t = "pack";
+    int n = s.length(), m = t.length();
+
+    // 暴力搜索
+    int res = editDistanceDFS(s, t, n, m);
+    cout << "将 " << s << " 更改为 " << t << " 最少需要编辑 " << res << " 步\n";
+
+    // 记忆化搜索
+    vector<vector<int>> mem(n + 1, vector<int>(m + 1, -1));
+    res = editDistanceDFSMem(s, t, mem, n, m);
+    cout << "将 " << s << " 更改为 " << t << " 最少需要编辑 " << res << " 步\n";
+
+    // 动态规划
+    res = editDistanceDP(s, t);
+    cout << "将 " << s << " 更改为 " << t << " 最少需要编辑 " << res << " 步\n";
+
+    // 空间优化后的动态规划
+    res = editDistanceDPComp(s, t);
+    cout << "将 " << s << " 更改为 " << t << " 最少需要编辑 " << res << " 步\n";
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/knapsack.cpp b/chapter_dynamic_programming/knapsack.cpp
new file mode 100644
index 0000000..a0848c8
--- /dev/null
+++ b/chapter_dynamic_programming/knapsack.cpp
@@ -0,0 +1,109 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+/* 0-1 背包：暴力搜索 */
+int knapsackDFS(vector<int> &wgt, vector<int> &val, int i, int c) {
+    // 若已选完所有物品或背包无剩余容量，则返回价值 0
+    if (i == 0 || c == 0) {
+        return 0;
+    }
+    // 若超过背包容量，则只能选择不放入背包
+    if (wgt[i - 1] > c) {
+        return knapsackDFS(wgt, val, i - 1, c);
+    }
+    // 计算不放入和放入物品 i 的最大价值
+    int no = knapsackDFS(wgt, val, i - 1, c);
+    int yes = knapsackDFS(wgt, val, i - 1, c - wgt[i - 1]) + val[i - 1];
+    // 返回两种方案中价值更大的那一个
+    return max(no, yes);
+}
+
+/* 0-1 背包：记忆化搜索 */
+int knapsackDFSMem(vector<int> &wgt, vector<int> &val, vector<vector<int>> &mem, int i, int c) {
+    // 若已选完所有物品或背包无剩余容量，则返回价值 0
+    if (i == 0 || c == 0) {
+        return 0;
+    }
+    // 若已有记录，则直接返回
+    if (mem[i][c] != -1) {
+        return mem[i][c];
+    }
+    // 若超过背包容量，则只能选择不放入背包
+    if (wgt[i - 1] > c) {
+        return knapsackDFSMem(wgt, val, mem, i - 1, c);
+    }
+    // 计算不放入和放入物品 i 的最大价值
+    int no = knapsackDFSMem(wgt, val, mem, i - 1, c);
+    int yes = knapsackDFSMem(wgt, val, mem, i - 1, c - wgt[i - 1]) + val[i - 1];
+    // 记录并返回两种方案中价值更大的那一个
+    mem[i][c] = max(no, yes);
+    return mem[i][c];
+}
+
+/* 0-1 背包：动态规划 */
+int knapsackDP(vector<int> &wgt, vector<int> &val, int cap) {
+    int n = wgt.size();
+    // 初始化 dp 表
+    vector<vector<int>> dp(n + 1, vector<int>(cap + 1, 0));
+    // 状态转移
+    for (int i = 1; i <= n; i++) {
+        for (int c = 1; c <= cap; c++) {
+            if (wgt[i - 1] > c) {
+                // 若超过背包容量，则不选物品 i
+                dp[i][c] = dp[i - 1][c];
+            } else {
+                // 不选和选物品 i 这两种方案的较大值
+                dp[i][c] = max(dp[i - 1][c], dp[i - 1][c - wgt[i - 1]] + val[i - 1]);
+            }
+        }
+    }
+    return dp[n][cap];
+}
+
+/* 0-1 背包：空间优化后的动态规划 */
+int knapsackDPComp(vector<int> &wgt, vector<int> &val, int cap) {
+    int n = wgt.size();
+    // 初始化 dp 表
+    vector<int> dp(cap + 1, 0);
+    // 状态转移
+    for (int i = 1; i <= n; i++) {
+        // 倒序遍历
+        for (int c = cap; c >= 1; c--) {
+            if (wgt[i - 1] <= c) {
+                // 不选和选物品 i 这两种方案的较大值
+                dp[c] = max(dp[c], dp[c - wgt[i - 1]] + val[i - 1]);
+            }
+        }
+    }
+    return dp[cap];
+}
+
+/* Driver Code */
+int main() {
+    vector<int> wgt = {10, 20, 30, 40, 50};
+    vector<int> val = {50, 120, 150, 210, 240};
+    int cap = 50;
+    int n = wgt.size();
+
+    // 暴力搜索
+    int res = knapsackDFS(wgt, val, n, cap);
+    cout << "不超过背包容量的最大物品价值为 " << res << endl;
+
+    // 记忆化搜索
+    vector<vector<int>> mem(n + 1, vector<int>(cap + 1, -1));
+    res = knapsackDFSMem(wgt, val, mem, n, cap);
+    cout << "不超过背包容量的最大物品价值为 " << res << endl;
+
+    // 动态规划
+    res = knapsackDP(wgt, val, cap);
+    cout << "不超过背包容量的最大物品价值为 " << res << endl;
+
+    // 空间优化后的动态规划
+    res = knapsackDPComp(wgt, val, cap);
+    cout << "不超过背包容量的最大物品价值为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/min_cost_climbing_stairs_dp.cpp b/chapter_dynamic_programming/min_cost_climbing_stairs_dp.cpp
new file mode 100644
index 0000000..7736940
--- /dev/null
+++ b/chapter_dynamic_programming/min_cost_climbing_stairs_dp.cpp
@@ -0,0 +1,53 @@
+/**
+ * File: min_cost_climbing_stairs_dp.cpp
+ * Created Time: 2023-06-30
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 爬楼梯最小代价：动态规划 */
+int minCostClimbingStairsDP(vector<int> &cost) {
+    int n = cost.size() - 1;
+    if (n == 1 || n == 2)
+        return cost[n];
+    // 初始化 dp 表，用于存储子问题的解
+    vector<int> dp(n + 1);
+    // 初始状态：预设最小子问题的解
+    dp[1] = cost[1];
+    dp[2] = cost[2];
+    // 状态转移：从较小子问题逐步求解较大子问题
+    for (int i = 3; i <= n; i++) {
+        dp[i] = min(dp[i - 1], dp[i - 2]) + cost[i];
+    }
+    return dp[n];
+}
+
+/* 爬楼梯最小代价：空间优化后的动态规划 */
+int minCostClimbingStairsDPComp(vector<int> &cost) {
+    int n = cost.size() - 1;
+    if (n == 1 || n == 2)
+        return cost[n];
+    int a = cost[1], b = cost[2];
+    for (int i = 3; i <= n; i++) {
+        int tmp = b;
+        b = min(a, tmp) + cost[i];
+        a = tmp;
+    }
+    return b;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> cost = {0, 1, 10, 1, 1, 1, 10, 1, 1, 10, 1};
+    cout << "输入楼梯的代价列表为 ";
+    printVector(cost);
+
+    int res = minCostClimbingStairsDP(cost);
+    cout << "爬完楼梯的最低代价为 " << res << endl;
+
+    res = minCostClimbingStairsDPComp(cost);
+    cout << "爬完楼梯的最低代价为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/min_path_sum.cpp b/chapter_dynamic_programming/min_path_sum.cpp
new file mode 100644
index 0000000..a59f6bc
--- /dev/null
+++ b/chapter_dynamic_programming/min_path_sum.cpp
@@ -0,0 +1,116 @@
+/**
+ * File: min_path_sum.cpp
+ * Created Time: 2023-07-10
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 最小路径和：暴力搜索 */
+int minPathSumDFS(vector<vector<int>> &grid, int i, int j) {
+    // 若为左上角单元格，则终止搜索
+    if (i == 0 && j == 0) {
+        return grid[0][0];
+    }
+    // 若行列索引越界，则返回 +∞ 代价
+    if (i < 0 || j < 0) {
+        return INT_MAX;
+    }
+    // 计算从左上角到 (i-1, j) 和 (i, j-1) 的最小路径代价
+    int up = minPathSumDFS(grid, i - 1, j);
+    int left = minPathSumDFS(grid, i, j - 1);
+    // 返回从左上角到 (i, j) 的最小路径代价
+    return min(left, up) != INT_MAX ? min(left, up) + grid[i][j] : INT_MAX;
+}
+
+/* 最小路径和：记忆化搜索 */
+int minPathSumDFSMem(vector<vector<int>> &grid, vector<vector<int>> &mem, int i, int j) {
+    // 若为左上角单元格，则终止搜索
+    if (i == 0 && j == 0) {
+        return grid[0][0];
+    }
+    // 若行列索引越界，则返回 +∞ 代价
+    if (i < 0 || j < 0) {
+        return INT_MAX;
+    }
+    // 若已有记录，则直接返回
+    if (mem[i][j] != -1) {
+        return mem[i][j];
+    }
+    // 左边和上边单元格的最小路径代价
+    int up = minPathSumDFSMem(grid, mem, i - 1, j);
+    int left = minPathSumDFSMem(grid, mem, i, j - 1);
+    // 记录并返回左上角到 (i, j) 的最小路径代价
+    mem[i][j] = min(left, up) != INT_MAX ? min(left, up) + grid[i][j] : INT_MAX;
+    return mem[i][j];
+}
+
+/* 最小路径和：动态规划 */
+int minPathSumDP(vector<vector<int>> &grid) {
+    int n = grid.size(), m = grid[0].size();
+    // 初始化 dp 表
+    vector<vector<int>> dp(n, vector<int>(m));
+    dp[0][0] = grid[0][0];
+    // 状态转移：首行
+    for (int j = 1; j < m; j++) {
+        dp[0][j] = dp[0][j - 1] + grid[0][j];
+    }
+    // 状态转移：首列
+    for (int i = 1; i < n; i++) {
+        dp[i][0] = dp[i - 1][0] + grid[i][0];
+    }
+    // 状态转移：其余行和列
+    for (int i = 1; i < n; i++) {
+        for (int j = 1; j < m; j++) {
+            dp[i][j] = min(dp[i][j - 1], dp[i - 1][j]) + grid[i][j];
+        }
+    }
+    return dp[n - 1][m - 1];
+}
+
+/* 最小路径和：空间优化后的动态规划 */
+int minPathSumDPComp(vector<vector<int>> &grid) {
+    int n = grid.size(), m = grid[0].size();
+    // 初始化 dp 表
+    vector<int> dp(m);
+    // 状态转移：首行
+    dp[0] = grid[0][0];
+    for (int j = 1; j < m; j++) {
+        dp[j] = dp[j - 1] + grid[0][j];
+    }
+    // 状态转移：其余行
+    for (int i = 1; i < n; i++) {
+        // 状态转移：首列
+        dp[0] = dp[0] + grid[i][0];
+        // 状态转移：其余列
+        for (int j = 1; j < m; j++) {
+            dp[j] = min(dp[j - 1], dp[j]) + grid[i][j];
+        }
+    }
+    return dp[m - 1];
+}
+
+/* Driver Code */
+int main() {
+    vector<vector<int>> grid = {{1, 3, 1, 5}, {2, 2, 4, 2}, {5, 3, 2, 1}, {4, 3, 5, 2}};
+    int n = grid.size(), m = grid[0].size();
+
+    // 暴力搜索
+    int res = minPathSumDFS(grid, n - 1, m - 1);
+    cout << "从左上角到右下角的最小路径和为 " << res << endl;
+
+    // 记忆化搜索
+    vector<vector<int>> mem(n, vector<int>(m, -1));
+    res = minPathSumDFSMem(grid, mem, n - 1, m - 1);
+    cout << "从左上角到右下角的最小路径和为 " << res << endl;
+
+    // 动态规划
+    res = minPathSumDP(grid);
+    cout << "从左上角到右下角的最小路径和为 " << res << endl;
+
+    // 空间优化后的动态规划
+    res = minPathSumDPComp(grid);
+    cout << "从左上角到右下角的最小路径和为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_dynamic_programming/unbounded_knapsack.cpp b/chapter_dynamic_programming/unbounded_knapsack.cpp
new file mode 100644
index 0000000..9e1b6dd
--- /dev/null
+++ b/chapter_dynamic_programming/unbounded_knapsack.cpp
@@ -0,0 +1,64 @@
+/**
+ * File: unbounded_knapsack.cpp
+ * Created Time: 2023-07-11
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 完全背包：动态规划 */
+int unboundedKnapsackDP(vector<int> &wgt, vector<int> &val, int cap) {
+    int n = wgt.size();
+    // 初始化 dp 表
+    vector<vector<int>> dp(n + 1, vector<int>(cap + 1, 0));
+    // 状态转移
+    for (int i = 1; i <= n; i++) {
+        for (int c = 1; c <= cap; c++) {
+            if (wgt[i - 1] > c) {
+                // 若超过背包容量，则不选物品 i
+                dp[i][c] = dp[i - 1][c];
+            } else {
+                // 不选和选物品 i 这两种方案的较大值
+                dp[i][c] = max(dp[i - 1][c], dp[i][c - wgt[i - 1]] + val[i - 1]);
+            }
+        }
+    }
+    return dp[n][cap];
+}
+
+/* 完全背包：空间优化后的动态规划 */
+int unboundedKnapsackDPComp(vector<int> &wgt, vector<int> &val, int cap) {
+    int n = wgt.size();
+    // 初始化 dp 表
+    vector<int> dp(cap + 1, 0);
+    // 状态转移
+    for (int i = 1; i <= n; i++) {
+        for (int c = 1; c <= cap; c++) {
+            if (wgt[i - 1] > c) {
+                // 若超过背包容量，则不选物品 i
+                dp[c] = dp[c];
+            } else {
+                // 不选和选物品 i 这两种方案的较大值
+                dp[c] = max(dp[c], dp[c - wgt[i - 1]] + val[i - 1]);
+            }
+        }
+    }
+    return dp[cap];
+}
+
+/* Driver code */
+int main() {
+    vector<int> wgt = {1, 2, 3};
+    vector<int> val = {5, 11, 15};
+    int cap = 4;
+
+    // 动态规划
+    int res = unboundedKnapsackDP(wgt, val, cap);
+    cout << "不超过背包容量的最大物品价值为 " << res << endl;
+
+    // 空间优化后的动态规划
+    res = unboundedKnapsackDPComp(wgt, val, cap);
+    cout << "不超过背包容量的最大物品价值为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_graph/CMakeLists.txt b/chapter_graph/CMakeLists.txt
new file mode 100644
index 0000000..4a56ce3
--- /dev/null
+++ b/chapter_graph/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_executable(graph_bfs graph_bfs.cpp)
+add_executable(graph_dfs graph_dfs.cpp)
+# add_executable(graph_adjacency_list graph_adjacency_list.cpp)
+add_executable(graph_adjacency_list_test graph_adjacency_list_test.cpp)
+add_executable(graph_adjacency_matrix graph_adjacency_matrix.cpp)
diff --git a/chapter_graph/graph_adjacency_list.cpp b/chapter_graph/graph_adjacency_list.cpp
new file mode 100644
index 0000000..e23026f
--- /dev/null
+++ b/chapter_graph/graph_adjacency_list.cpp
@@ -0,0 +1,90 @@
+/**
+ * File: graph_adjacency_list.cpp
+ * Created Time: 2023-02-09
+ * Author: what-is-me (whatisme@outlook.jp), krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于邻接表实现的无向图类 */
+class GraphAdjList {
+  public:
+    // 邻接表，key：顶点，value：该顶点的所有邻接顶点
+    unordered_map<Vertex *, vector<Vertex *>> adjList;
+
+    /* 在 vector 中删除指定节点 */
+    void remove(vector<Vertex *> &vec, Vertex *vet) {
+        for (int i = 0; i < vec.size(); i++) {
+            if (vec[i] == vet) {
+                vec.erase(vec.begin() + i);
+                break;
+            }
+        }
+    }
+
+    /* 构造方法 */
+    GraphAdjList(const vector<vector<Vertex *>> &edges) {
+        // 添加所有顶点和边
+        for (const vector<Vertex *> &edge : edges) {
+            addVertex(edge[0]);
+            addVertex(edge[1]);
+            addEdge(edge[0], edge[1]);
+        }
+    }
+
+    /* 获取顶点数量 */
+    int size() {
+        return adjList.size();
+    }
+
+    /* 添加边 */
+    void addEdge(Vertex *vet1, Vertex *vet2) {
+        if (!adjList.count(vet1) || !adjList.count(vet2) || vet1 == vet2)
+            throw invalid_argument("不存在顶点");
+        // 添加边 vet1 - vet2
+        adjList[vet1].push_back(vet2);
+        adjList[vet2].push_back(vet1);
+    }
+
+    /* 删除边 */
+    void removeEdge(Vertex *vet1, Vertex *vet2) {
+        if (!adjList.count(vet1) || !adjList.count(vet2) || vet1 == vet2)
+            throw invalid_argument("不存在顶点");
+        // 删除边 vet1 - vet2
+        remove(adjList[vet1], vet2);
+        remove(adjList[vet2], vet1);
+    }
+
+    /* 添加顶点 */
+    void addVertex(Vertex *vet) {
+        if (adjList.count(vet))
+            return;
+        // 在邻接表中添加一个新链表
+        adjList[vet] = vector<Vertex *>();
+    }
+
+    /* 删除顶点 */
+    void removeVertex(Vertex *vet) {
+        if (!adjList.count(vet))
+            throw invalid_argument("不存在顶点");
+        // 在邻接表中删除顶点 vet 对应的链表
+        adjList.erase(vet);
+        // 遍历其他顶点的链表，删除所有包含 vet 的边
+        for (auto &adj : adjList) {
+            remove(adj.second, vet);
+        }
+    }
+
+    /* 打印邻接表 */
+    void print() {
+        cout << "邻接表 =" << endl;
+        for (auto &adj : adjList) {
+            const auto &key = adj.first;
+            const auto &vec = adj.second;
+            cout << key->val << ": ";
+            printVector(vetsToVals(vec));
+        }
+    }
+};
+
+// 测试样例请见 graph_adjacency_list_test.cpp
diff --git a/chapter_graph/graph_adjacency_list_test.cpp b/chapter_graph/graph_adjacency_list_test.cpp
new file mode 100644
index 0000000..39ea794
--- /dev/null
+++ b/chapter_graph/graph_adjacency_list_test.cpp
@@ -0,0 +1,49 @@
+/**
+ * File: graph_adjacency_list_test.cpp
+ * Created Time: 2023-02-09
+ * Author: what-is-me (whatisme@outlook.jp), krahets (krahets@163.com)
+ */
+
+#include "./graph_adjacency_list.cpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化无向图 */
+    vector<Vertex *> v = valsToVets(vector<int>{1, 3, 2, 5, 4});
+    vector<vector<Vertex *>> edges = {{v[0], v[1]}, {v[0], v[3]}, {v[1], v[2]},
+                                      {v[2], v[3]}, {v[2], v[4]}, {v[3], v[4]}};
+    GraphAdjList graph(edges);
+    cout << "\n初始化后，图为" << endl;
+    graph.print();
+
+    /* 添加边 */
+    // 顶点 1, 2 即 v[0], v[2]
+    graph.addEdge(v[0], v[2]);
+    cout << "\n添加边 1-2 后，图为" << endl;
+    graph.print();
+
+    /* 删除边 */
+    // 顶点 1, 3 即 v[0], v[1]
+    graph.removeEdge(v[0], v[1]);
+    cout << "\n删除边 1-3 后，图为" << endl;
+    graph.print();
+
+    /* 添加顶点 */
+    Vertex *v5 = new Vertex(6);
+    graph.addVertex(v5);
+    cout << "\n添加顶点 6 后，图为" << endl;
+    graph.print();
+
+    /* 删除顶点 */
+    // 顶点 3 即 v[1]
+    graph.removeVertex(v[1]);
+    cout << "\n删除顶点 3 后，图为" << endl;
+    graph.print();
+
+    // 释放内存
+    for (Vertex *vet : v) {
+        delete vet;
+    }
+
+    return 0;
+}
diff --git a/chapter_graph/graph_adjacency_matrix.cpp b/chapter_graph/graph_adjacency_matrix.cpp
new file mode 100644
index 0000000..91d51a6
--- /dev/null
+++ b/chapter_graph/graph_adjacency_matrix.cpp
@@ -0,0 +1,127 @@
+/**
+ * File: graph_adjacency_matrix.cpp
+ * Created Time: 2023-02-09
+ * Author: what-is-me (whatisme@outlook.jp)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于邻接矩阵实现的无向图类 */
+class GraphAdjMat {
+    vector<int> vertices;       // 顶点列表，元素代表“顶点值”，索引代表“顶点索引”
+    vector<vector<int>> adjMat; // 邻接矩阵，行列索引对应“顶点索引”
+
+  public:
+    /* 构造方法 */
+    GraphAdjMat(const vector<int> &vertices, const vector<vector<int>> &edges) {
+        // 添加顶点
+        for (int val : vertices) {
+            addVertex(val);
+        }
+        // 添加边
+        // 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
+        for (const vector<int> &edge : edges) {
+            addEdge(edge[0], edge[1]);
+        }
+    }
+
+    /* 获取顶点数量 */
+    int size() const {
+        return vertices.size();
+    }
+
+    /* 添加顶点 */
+    void addVertex(int val) {
+        int n = size();
+        // 向顶点列表中添加新顶点的值
+        vertices.push_back(val);
+        // 在邻接矩阵中添加一行
+        adjMat.emplace_back(vector<int>(n, 0));
+        // 在邻接矩阵中添加一列
+        for (vector<int> &row : adjMat) {
+            row.push_back(0);
+        }
+    }
+
+    /* 删除顶点 */
+    void removeVertex(int index) {
+        if (index >= size()) {
+            throw out_of_range("顶点不存在");
+        }
+        // 在顶点列表中移除索引 index 的顶点
+        vertices.erase(vertices.begin() + index);
+        // 在邻接矩阵中删除索引 index 的行
+        adjMat.erase(adjMat.begin() + index);
+        // 在邻接矩阵中删除索引 index 的列
+        for (vector<int> &row : adjMat) {
+            row.erase(row.begin() + index);
+        }
+    }
+
+    /* 添加边 */
+    // 参数 i, j 对应 vertices 元素索引
+    void addEdge(int i, int j) {
+        // 索引越界与相等处理
+        if (i < 0 || j < 0 || i >= size() || j >= size() || i == j) {
+            throw out_of_range("顶点不存在");
+        }
+        // 在无向图中，邻接矩阵关于主对角线对称，即满足 (i, j) == (j, i)
+        adjMat[i][j] = 1;
+        adjMat[j][i] = 1;
+    }
+
+    /* 删除边 */
+    // 参数 i, j 对应 vertices 元素索引
+    void removeEdge(int i, int j) {
+        // 索引越界与相等处理
+        if (i < 0 || j < 0 || i >= size() || j >= size() || i == j) {
+            throw out_of_range("顶点不存在");
+        }
+        adjMat[i][j] = 0;
+        adjMat[j][i] = 0;
+    }
+
+    /* 打印邻接矩阵 */
+    void print() {
+        cout << "顶点列表 = ";
+        printVector(vertices);
+        cout << "邻接矩阵 =" << endl;
+        printVectorMatrix(adjMat);
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化无向图 */
+    // 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
+    vector<int> vertices = {1, 3, 2, 5, 4};
+    vector<vector<int>> edges = {{0, 1}, {0, 3}, {1, 2}, {2, 3}, {2, 4}, {3, 4}};
+    GraphAdjMat graph(vertices, edges);
+    cout << "\n初始化后，图为" << endl;
+    graph.print();
+
+    /* 添加边 */
+    // 顶点 1, 2 的索引分别为 0, 2
+    graph.addEdge(0, 2);
+    cout << "\n添加边 1-2 后，图为" << endl;
+    graph.print();
+
+    /* 删除边 */
+    // 顶点 1, 3 的索引分别为 0, 1
+    graph.removeEdge(0, 1);
+    cout << "\n删除边 1-3 后，图为" << endl;
+    graph.print();
+
+    /* 添加顶点 */
+    graph.addVertex(6);
+    cout << "\n添加顶点 6 后，图为" << endl;
+    graph.print();
+
+    /* 删除顶点 */
+    // 顶点 3 的索引为 1
+    graph.removeVertex(1);
+    cout << "\n删除顶点 3 后，图为" << endl;
+    graph.print();
+
+    return 0;
+}
diff --git a/chapter_graph/graph_bfs.cpp b/chapter_graph/graph_bfs.cpp
new file mode 100644
index 0000000..a4efd8a
--- /dev/null
+++ b/chapter_graph/graph_bfs.cpp
@@ -0,0 +1,59 @@
+/**
+ * File: graph_bfs.cpp
+ * Created Time: 2023-03-02
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+#include "./graph_adjacency_list.cpp"
+
+/* 广度优先遍历 */
+// 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
+vector<Vertex *> graphBFS(GraphAdjList &graph, Vertex *startVet) {
+    // 顶点遍历序列
+    vector<Vertex *> res;
+    // 哈希表，用于记录已被访问过的顶点
+    unordered_set<Vertex *> visited = {startVet};
+    // 队列用于实现 BFS
+    queue<Vertex *> que;
+    que.push(startVet);
+    // 以顶点 vet 为起点，循环直至访问完所有顶点
+    while (!que.empty()) {
+        Vertex *vet = que.front();
+        que.pop();          // 队首顶点出队
+        res.push_back(vet); // 记录访问顶点
+        // 遍历该顶点的所有邻接顶点
+        for (auto adjVet : graph.adjList[vet]) {
+            if (visited.count(adjVet))
+                continue;            // 跳过已被访问的顶点
+            que.push(adjVet);        // 只入队未访问的顶点
+            visited.emplace(adjVet); // 标记该顶点已被访问
+        }
+    }
+    // 返回顶点遍历序列
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化无向图 */
+    vector<Vertex *> v = valsToVets({0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
+    vector<vector<Vertex *>> edges = {{v[0], v[1]}, {v[0], v[3]}, {v[1], v[2]}, {v[1], v[4]},
+                                      {v[2], v[5]}, {v[3], v[4]}, {v[3], v[6]}, {v[4], v[5]},
+                                      {v[4], v[7]}, {v[5], v[8]}, {v[6], v[7]}, {v[7], v[8]}};
+    GraphAdjList graph(edges);
+    cout << "\n初始化后，图为\\n";
+    graph.print();
+
+    /* 广度优先遍历 */
+    vector<Vertex *> res = graphBFS(graph, v[0]);
+    cout << "\n广度优先遍历（BFS）顶点序列为" << endl;
+    printVector(vetsToVals(res));
+
+    // 释放内存
+    for (Vertex *vet : v) {
+        delete vet;
+    }
+
+    return 0;
+}
diff --git a/chapter_graph/graph_dfs.cpp b/chapter_graph/graph_dfs.cpp
new file mode 100644
index 0000000..e1c5c6f
--- /dev/null
+++ b/chapter_graph/graph_dfs.cpp
@@ -0,0 +1,55 @@
+/**
+ * File: graph_dfs.cpp
+ * Created Time: 2023-03-02
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+#include "./graph_adjacency_list.cpp"
+
+/* 深度优先遍历辅助函数 */
+void dfs(GraphAdjList &graph, unordered_set<Vertex *> &visited, vector<Vertex *> &res, Vertex *vet) {
+    res.push_back(vet);   // 记录访问顶点
+    visited.emplace(vet); // 标记该顶点已被访问
+    // 遍历该顶点的所有邻接顶点
+    for (Vertex *adjVet : graph.adjList[vet]) {
+        if (visited.count(adjVet))
+            continue; // 跳过已被访问的顶点
+        // 递归访问邻接顶点
+        dfs(graph, visited, res, adjVet);
+    }
+}
+
+/* 深度优先遍历 */
+// 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
+vector<Vertex *> graphDFS(GraphAdjList &graph, Vertex *startVet) {
+    // 顶点遍历序列
+    vector<Vertex *> res;
+    // 哈希表，用于记录已被访问过的顶点
+    unordered_set<Vertex *> visited;
+    dfs(graph, visited, res, startVet);
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化无向图 */
+    vector<Vertex *> v = valsToVets(vector<int>{0, 1, 2, 3, 4, 5, 6});
+    vector<vector<Vertex *>> edges = {{v[0], v[1]}, {v[0], v[3]}, {v[1], v[2]},
+                                      {v[2], v[5]}, {v[4], v[5]}, {v[5], v[6]}};
+    GraphAdjList graph(edges);
+    cout << "\n初始化后，图为" << endl;
+    graph.print();
+
+    /* 深度优先遍历 */
+    vector<Vertex *> res = graphDFS(graph, v[0]);
+    cout << "\n深度优先遍历（DFS）顶点序列为" << endl;
+    printVector(vetsToVals(res));
+
+    // 释放内存
+    for (Vertex *vet : v) {
+        delete vet;
+    }
+
+    return 0;
+}
diff --git a/chapter_greedy/CMakeLists.txt b/chapter_greedy/CMakeLists.txt
new file mode 100644
index 0000000..9178866
--- /dev/null
+++ b/chapter_greedy/CMakeLists.txt
@@ -0,0 +1,3 @@
+add_executable(coin_change_greedy coin_change_greedy.cpp)
+add_executable(fractional_knapsack fractional_knapsack.cpp)
+add_executable(max_capacity max_capacity.cpp)
\ No newline at end of file
diff --git a/chapter_greedy/coin_change_greedy.cpp b/chapter_greedy/coin_change_greedy.cpp
new file mode 100644
index 0000000..5f1db7c
--- /dev/null
+++ b/chapter_greedy/coin_change_greedy.cpp
@@ -0,0 +1,60 @@
+/**
+ * File: coin_change_greedy.cpp
+ * Created Time: 2023-07-20
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 零钱兑换：贪心 */
+int coinChangeGreedy(vector<int> &coins, int amt) {
+    // 假设 coins 列表有序
+    int i = coins.size() - 1;
+    int count = 0;
+    // 循环进行贪心选择，直到无剩余金额
+    while (amt > 0) {
+        // 找到小于且最接近剩余金额的硬币
+        while (i > 0 && coins[i] > amt) {
+            i--;
+        }
+        // 选择 coins[i]
+        amt -= coins[i];
+        count++;
+    }
+    // 若未找到可行方案，则返回 -1
+    return amt == 0 ? count : -1;
+}
+
+/* Driver Code */
+int main() {
+    // 贪心：能够保证找到全局最优解
+    vector<int> coins = {1, 5, 10, 20, 50, 100};
+    int amt = 186;
+    int res = coinChangeGreedy(coins, amt);
+    cout << "\ncoins = ";
+    printVector(coins);
+    cout << "amt = " << amt << endl;
+    cout << "凑到 " << amt << " 所需的最少硬币数量为 " << res << endl;
+
+    // 贪心：无法保证找到全局最优解
+    coins = {1, 20, 50};
+    amt = 60;
+    res = coinChangeGreedy(coins, amt);
+    cout << "\ncoins = ";
+    printVector(coins);
+    cout << "amt = " << amt << endl;
+    cout << "凑到 " << amt << " 所需的最少硬币数量为 " << res << endl;
+    cout << "实际上需要的最少数量为 3 ，即 20 + 20 + 20" << endl;
+
+    // 贪心：无法保证找到全局最优解
+    coins = {1, 49, 50};
+    amt = 98;
+    res = coinChangeGreedy(coins, amt);
+    cout << "\ncoins = ";
+    printVector(coins);
+    cout << "amt = " << amt << endl;
+    cout << "凑到 " << amt << " 所需的最少硬币数量为 " << res << endl;
+    cout << "实际上需要的最少数量为 2 ，即 49 + 49" << endl;
+
+    return 0;
+}
diff --git a/chapter_greedy/fractional_knapsack.cpp b/chapter_greedy/fractional_knapsack.cpp
new file mode 100644
index 0000000..a9cdc4f
--- /dev/null
+++ b/chapter_greedy/fractional_knapsack.cpp
@@ -0,0 +1,56 @@
+/**
+ * File: fractional_knapsack.cpp
+ * Created Time: 2023-07-20
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 物品 */
+class Item {
+  public:
+    int w; // 物品重量
+    int v; // 物品价值
+
+    Item(int w, int v) : w(w), v(v) {
+    }
+};
+
+/* 分数背包：贪心 */
+double fractionalKnapsack(vector<int> &wgt, vector<int> &val, int cap) {
+    // 创建物品列表，包含两个属性：重量、价值
+    vector<Item> items;
+    for (int i = 0; i < wgt.size(); i++) {
+        items.push_back(Item(wgt[i], val[i]));
+    }
+    // 按照单位价值 item.v / item.w 从高到低进行排序
+    sort(items.begin(), items.end(), [](Item &a, Item &b) { return (double)a.v / a.w > (double)b.v / b.w; });
+    // 循环贪心选择
+    double res = 0;
+    for (auto &item : items) {
+        if (item.w <= cap) {
+            // 若剩余容量充足，则将当前物品整个装进背包
+            res += item.v;
+            cap -= item.w;
+        } else {
+            // 若剩余容量不足，则将当前物品的一部分装进背包
+            res += (double)item.v / item.w * cap;
+            // 已无剩余容量，因此跳出循环
+            break;
+        }
+    }
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> wgt = {10, 20, 30, 40, 50};
+    vector<int> val = {50, 120, 150, 210, 240};
+    int cap = 50;
+
+    // 贪心算法
+    double res = fractionalKnapsack(wgt, val, cap);
+    cout << "不超过背包容量的最大物品价值为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_greedy/max_capacity.cpp b/chapter_greedy/max_capacity.cpp
new file mode 100644
index 0000000..eff2f6c
--- /dev/null
+++ b/chapter_greedy/max_capacity.cpp
@@ -0,0 +1,39 @@
+/**
+ * File: max_capacity.cpp
+ * Created Time: 2023-07-21
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 最大容量：贪心 */
+int maxCapacity(vector<int> &ht) {
+    // 初始化 i, j，使其分列数组两端
+    int i = 0, j = ht.size() - 1;
+    // 初始最大容量为 0
+    int res = 0;
+    // 循环贪心选择，直至两板相遇
+    while (i < j) {
+        // 更新最大容量
+        int cap = min(ht[i], ht[j]) * (j - i);
+        res = max(res, cap);
+        // 向内移动短板
+        if (ht[i] < ht[j]) {
+            i++;
+        } else {
+            j--;
+        }
+    }
+    return res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> ht = {3, 8, 5, 2, 7, 7, 3, 4};
+
+    // 贪心算法
+    int res = maxCapacity(ht);
+    cout << "最大容量为 " << res << endl;
+
+    return 0;
+}
diff --git a/chapter_greedy/max_product_cutting.cpp b/chapter_greedy/max_product_cutting.cpp
new file mode 100644
index 0000000..880d828
--- /dev/null
+++ b/chapter_greedy/max_product_cutting.cpp
@@ -0,0 +1,39 @@
+/**
+ * File: max_product_cutting.cpp
+ * Created Time: 2023-07-21
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 最大切分乘积：贪心 */
+int maxProductCutting(int n) {
+    // 当 n <= 3 时，必须切分出一个 1
+    if (n <= 3) {
+        return 1 * (n - 1);
+    }
+    // 贪心地切分出 3 ，a 为 3 的个数，b 为余数
+    int a = n / 3;
+    int b = n % 3;
+    if (b == 1) {
+        // 当余数为 1 时，将一对 1 * 3 转化为 2 * 2
+        return (int)pow(3, a - 1) * 2 * 2;
+    }
+    if (b == 2) {
+        // 当余数为 2 时，不做处理
+        return (int)pow(3, a) * 2;
+    }
+    // 当余数为 0 时，不做处理
+    return (int)pow(3, a);
+}
+
+/* Driver Code */
+int main() {
+    int n = 58;
+
+    // 贪心算法
+    int res = maxProductCutting(n);
+    cout << "最大切分乘积为" << res << endl;
+
+    return 0;
+}
diff --git a/chapter_hashing/CMakeLists.txt b/chapter_hashing/CMakeLists.txt
new file mode 100644
index 0000000..6b583ef
--- /dev/null
+++ b/chapter_hashing/CMakeLists.txt
@@ -0,0 +1,6 @@
+add_executable(hash_map hash_map.cpp)
+add_executable(array_hash_map_test array_hash_map_test.cpp)
+add_executable(hash_map_chaining hash_map_chaining.cpp)
+add_executable(hash_map_open_addressing hash_map_open_addressing.cpp)
+add_executable(simple_hash simple_hash.cpp)
+add_executable(built_in_hash built_in_hash.cpp)
\ No newline at end of file
diff --git a/chapter_hashing/array_hash_map.cpp b/chapter_hashing/array_hash_map.cpp
new file mode 100644
index 0000000..96a1a14
--- /dev/null
+++ b/chapter_hashing/array_hash_map.cpp
@@ -0,0 +1,110 @@
+/**
+ * File: array_hash_map.cpp
+ * Created Time: 2022-12-14
+ * Author: msk397 (machangxinq@gmail.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 键值对 */
+struct Pair {
+  public:
+    int key;
+    string val;
+    Pair(int key, string val) {
+        this->key = key;
+        this->val = val;
+    }
+};
+
+/* 基于数组实现的哈希表 */
+class ArrayHashMap {
+  private:
+    vector<Pair *> buckets;
+
+  public:
+    ArrayHashMap() {
+        // 初始化数组，包含 100 个桶
+        buckets = vector<Pair *>(100);
+    }
+
+    ~ArrayHashMap() {
+        // 释放内存
+        for (const auto &bucket : buckets) {
+            delete bucket;
+        }
+        buckets.clear();
+    }
+
+    /* 哈希函数 */
+    int hashFunc(int key) {
+        int index = key % 100;
+        return index;
+    }
+
+    /* 查询操作 */
+    string get(int key) {
+        int index = hashFunc(key);
+        Pair *pair = buckets[index];
+        if (pair == nullptr)
+            return "";
+        return pair->val;
+    }
+
+    /* 添加操作 */
+    void put(int key, string val) {
+        Pair *pair = new Pair(key, val);
+        int index = hashFunc(key);
+        buckets[index] = pair;
+    }
+
+    /* 删除操作 */
+    void remove(int key) {
+        int index = hashFunc(key);
+        // 释放内存并置为 nullptr
+        delete buckets[index];
+        buckets[index] = nullptr;
+    }
+
+    /* 获取所有键值对 */
+    vector<Pair *> pairSet() {
+        vector<Pair *> pairSet;
+        for (Pair *pair : buckets) {
+            if (pair != nullptr) {
+                pairSet.push_back(pair);
+            }
+        }
+        return pairSet;
+    }
+
+    /* 获取所有键 */
+    vector<int> keySet() {
+        vector<int> keySet;
+        for (Pair *pair : buckets) {
+            if (pair != nullptr) {
+                keySet.push_back(pair->key);
+            }
+        }
+        return keySet;
+    }
+
+    /* 获取所有值 */
+    vector<string> valueSet() {
+        vector<string> valueSet;
+        for (Pair *pair : buckets) {
+            if (pair != nullptr) {
+                valueSet.push_back(pair->val);
+            }
+        }
+        return valueSet;
+    }
+
+    /* 打印哈希表 */
+    void print() {
+        for (Pair *kv : pairSet()) {
+            cout << kv->key << " -> " << kv->val << endl;
+        }
+    }
+};
+
+// 测试样例请见 array_hash_map_test.cpp
diff --git a/chapter_hashing/array_hash_map_test.cpp b/chapter_hashing/array_hash_map_test.cpp
new file mode 100644
index 0000000..4b3ccc8
--- /dev/null
+++ b/chapter_hashing/array_hash_map_test.cpp
@@ -0,0 +1,52 @@
+/**
+ * File: array_hash_map_test.cpp
+ * Created Time: 2022-12-14
+ * Author: msk397 (machangxinq@gmail.com)
+ */
+
+#include "./array_hash_map.cpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化哈希表 */
+    ArrayHashMap map = ArrayHashMap();
+
+    /* 添加操作 */
+    // 在哈希表中添加键值对 (key, value)
+    map.put(12836, "小哈");
+    map.put(15937, "小啰");
+    map.put(16750, "小算");
+    map.put(13276, "小法");
+    map.put(10583, "小鸭");
+    cout << "\n添加完成后，哈希表为\nKey -> Value" << endl;
+    map.print();
+
+    /* 查询操作 */
+    // 向哈希表中输入键 key ，得到值 value
+    string name = map.get(15937);
+    cout << "\n输入学号 15937 ，查询到姓名 " << name << endl;
+
+    /* 删除操作 */
+    // 在哈希表中删除键值对 (key, value)
+    map.remove(10583);
+    cout << "\n删除 10583 后，哈希表为\nKey -> Value" << endl;
+    map.print();
+
+    /* 遍历哈希表 */
+    cout << "\n遍历键值对 Key->Value" << endl;
+    for (auto kv : map.pairSet()) {
+        cout << kv->key << " -> " << kv->val << endl;
+    }
+
+    cout << "\n单独遍历键 Key" << endl;
+    for (auto key : map.keySet()) {
+        cout << key << endl;
+    }
+
+    cout << "\n单独遍历值 Value" << endl;
+    for (auto val : map.valueSet()) {
+        cout << val << endl;
+    }
+
+    return 0;
+}
diff --git a/chapter_hashing/built_in_hash.cpp b/chapter_hashing/built_in_hash.cpp
new file mode 100644
index 0000000..da3f90c
--- /dev/null
+++ b/chapter_hashing/built_in_hash.cpp
@@ -0,0 +1,29 @@
+/**
+ * File: built_in_hash.cpp
+ * Created Time: 2023-06-21
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Driver Code */
+int main() {
+    int num = 3;
+    size_t hashNum = hash<int>()(num);
+    cout << "整数 " << num << " 的哈希值为 " << hashNum << "\n";
+
+    bool bol = true;
+    size_t hashBol = hash<bool>()(bol);
+    cout << "布尔量 " << bol << " 的哈希值为 " << hashBol << "\n";
+
+    double dec = 3.14159;
+    size_t hashDec = hash<double>()(dec);
+    cout << "小数 " << dec << " 的哈希值为 " << hashDec << "\n";
+
+    string str = "Hello 算法";
+    size_t hashStr = hash<string>()(str);
+    cout << "字符串 " << str << " 的哈希值为 " << hashStr << "\n";
+
+    // 在 C++ 中，内置 std:hash() 仅提供基本数据类型的哈希值计算
+    // 数组、对象的哈希值计算需要自行实现
+}
diff --git a/chapter_hashing/hash_map.cpp b/chapter_hashing/hash_map.cpp
new file mode 100644
index 0000000..8875032
--- /dev/null
+++ b/chapter_hashing/hash_map.cpp
@@ -0,0 +1,46 @@
+/**
+ * File: hash_map.cpp
+ * Created Time: 2022-12-14
+ * Author: msk397 (machangxinq@gmail.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化哈希表 */
+    unordered_map<int, string> map;
+
+    /* 添加操作 */
+    // 在哈希表中添加键值对 (key, value)
+    map[12836] = "小哈";
+    map[15937] = "小啰";
+    map[16750] = "小算";
+    map[13276] = "小法";
+    map[10583] = "小鸭";
+    cout << "\n添加完成后，哈希表为\nKey -> Value" << endl;
+    printHashMap(map);
+
+    /* 查询操作 */
+    // 向哈希表中输入键 key ，得到值 value
+    string name = map[15937];
+    cout << "\n输入学号 15937 ，查询到姓名 " << name << endl;
+
+    /* 删除操作 */
+    // 在哈希表中删除键值对 (key, value)
+    map.erase(10583);
+    cout << "\n删除 10583 后，哈希表为\nKey -> Value" << endl;
+    printHashMap(map);
+
+    /* 遍历哈希表 */
+    cout << "\n遍历键值对 Key->Value" << endl;
+    for (auto kv : map) {
+        cout << kv.first << " -> " << kv.second << endl;
+    }
+    cout << "\n使用迭代器遍历 Key->Value" << endl;
+    for (auto iter = map.begin(); iter != map.end(); iter++) {
+        cout << iter->first << "->" << iter->second << endl;
+    }
+
+    return 0;
+}
diff --git a/chapter_hashing/hash_map_chaining.cpp b/chapter_hashing/hash_map_chaining.cpp
new file mode 100644
index 0000000..4fc373e
--- /dev/null
+++ b/chapter_hashing/hash_map_chaining.cpp
@@ -0,0 +1,150 @@
+/**
+ * File: hash_map_chaining.cpp
+ * Created Time: 2023-06-13
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "./array_hash_map.cpp"
+
+/* 链式地址哈希表 */
+class HashMapChaining {
+  private:
+    int size;                       // 键值对数量
+    int capacity;                   // 哈希表容量
+    double loadThres;               // 触发扩容的负载因子阈值
+    int extendRatio;                // 扩容倍数
+    vector<vector<Pair *>> buckets; // 桶数组
+
+  public:
+    /* 构造方法 */
+    HashMapChaining() : size(0), capacity(4), loadThres(2.0 / 3.0), extendRatio(2) {
+        buckets.resize(capacity);
+    }
+
+    /* 析构方法 */
+    ~HashMapChaining() {
+        for (auto &bucket : buckets) {
+            for (Pair *pair : bucket) {
+                // 释放内存
+                delete pair;
+            }
+        }
+    }
+
+    /* 哈希函数 */
+    int hashFunc(int key) {
+        return key % capacity;
+    }
+
+    /* 负载因子 */
+    double loadFactor() {
+        return (double)size / (double)capacity;
+    }
+
+    /* 查询操作 */
+    string get(int key) {
+        int index = hashFunc(key);
+        // 遍历桶，若找到 key ，则返回对应 val
+        for (Pair *pair : buckets[index]) {
+            if (pair->key == key) {
+                return pair->val;
+            }
+        }
+        // 若未找到 key ，则返回空字符串
+        return "";
+    }
+
+    /* 添加操作 */
+    void put(int key, string val) {
+        // 当负载因子超过阈值时，执行扩容
+        if (loadFactor() > loadThres) {
+            extend();
+        }
+        int index = hashFunc(key);
+        // 遍历桶，若遇到指定 key ，则更新对应 val 并返回
+        for (Pair *pair : buckets[index]) {
+            if (pair->key == key) {
+                pair->val = val;
+                return;
+            }
+        }
+        // 若无该 key ，则将键值对添加至尾部
+        buckets[index].push_back(new Pair(key, val));
+        size++;
+    }
+
+    /* 删除操作 */
+    void remove(int key) {
+        int index = hashFunc(key);
+        auto &bucket = buckets[index];
+        // 遍历桶，从中删除键值对
+        for (int i = 0; i < bucket.size(); i++) {
+            if (bucket[i]->key == key) {
+                Pair *tmp = bucket[i];
+                bucket.erase(bucket.begin() + i); // 从中删除键值对
+                delete tmp;                       // 释放内存
+                size--;
+                return;
+            }
+        }
+    }
+
+    /* 扩容哈希表 */
+    void extend() {
+        // 暂存原哈希表
+        vector<vector<Pair *>> bucketsTmp = buckets;
+        // 初始化扩容后的新哈希表
+        capacity *= extendRatio;
+        buckets.clear();
+        buckets.resize(capacity);
+        size = 0;
+        // 将键值对从原哈希表搬运至新哈希表
+        for (auto &bucket : bucketsTmp) {
+            for (Pair *pair : bucket) {
+                put(pair->key, pair->val);
+                // 释放内存
+                delete pair;
+            }
+        }
+    }
+
+    /* 打印哈希表 */
+    void print() {
+        for (auto &bucket : buckets) {
+            cout << "[";
+            for (Pair *pair : bucket) {
+                cout << pair->key << " -> " << pair->val << ", ";
+            }
+            cout << "]\n";
+        }
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化哈希表 */
+    HashMapChaining map = HashMapChaining();
+
+    /* 添加操作 */
+    // 在哈希表中添加键值对 (key, value)
+    map.put(12836, "小哈");
+    map.put(15937, "小啰");
+    map.put(16750, "小算");
+    map.put(13276, "小法");
+    map.put(10583, "小鸭");
+    cout << "\n添加完成后，哈希表为\nKey -> Value" << endl;
+    map.print();
+
+    /* 查询操作 */
+    // 向哈希表中输入键 key ，得到值 value
+    string name = map.get(13276);
+    cout << "\n输入学号 13276 ，查询到姓名 " << name << endl;
+
+    /* 删除操作 */
+    // 在哈希表中删除键值对 (key, value)
+    map.remove(12836);
+    cout << "\n删除 12836 后，哈希表为\nKey -> Value" << endl;
+    map.print();
+
+    return 0;
+}
diff --git a/chapter_hashing/hash_map_open_addressing.cpp b/chapter_hashing/hash_map_open_addressing.cpp
new file mode 100644
index 0000000..7f9bf5a
--- /dev/null
+++ b/chapter_hashing/hash_map_open_addressing.cpp
@@ -0,0 +1,171 @@
+/**
+ * File: hash_map_open_addressing.cpp
+ * Created Time: 2023-06-13
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "./array_hash_map.cpp"
+
+/* 开放寻址哈希表 */
+class HashMapOpenAddressing {
+  private:
+    int size;                             // 键值对数量
+    int capacity = 4;                     // 哈希表容量
+    const double loadThres = 2.0 / 3.0;     // 触发扩容的负载因子阈值
+    const int extendRatio = 2;            // 扩容倍数
+    vector<Pair *> buckets;               // 桶数组
+    Pair *TOMBSTONE = new Pair(-1, "-1"); // 删除标记
+
+  public:
+    /* 构造方法 */
+    HashMapOpenAddressing() : size(0), buckets(capacity, nullptr) {
+    }
+
+    /* 析构方法 */
+    ~HashMapOpenAddressing() {
+        for (Pair *pair : buckets) {
+            if (pair != nullptr && pair != TOMBSTONE) {
+                delete pair;
+            }
+        }
+        delete TOMBSTONE;
+    }
+
+    /* 哈希函数 */
+    int hashFunc(int key) {
+        return key % capacity;
+    }
+
+    /* 负载因子 */
+    double loadFactor() {
+        return (double)size / capacity;
+    }
+
+    /* 搜索 key 对应的桶索引 */
+    int findBucket(int key) {
+        int index = hashFunc(key);
+        int firstTombstone = -1;
+        // 线性探测，当遇到空桶时跳出
+        while (buckets[index] != nullptr) {
+            // 若遇到 key ，返回对应的桶索引
+            if (buckets[index]->key == key) {
+                // 若之前遇到了删除标记，则将键值对移动至该索引处
+                if (firstTombstone != -1) {
+                    buckets[firstTombstone] = buckets[index];
+                    buckets[index] = TOMBSTONE;
+                    return firstTombstone; // 返回移动后的桶索引
+                }
+                return index; // 返回桶索引
+            }
+            // 记录遇到的首个删除标记
+            if (firstTombstone == -1 && buckets[index] == TOMBSTONE) {
+                firstTombstone = index;
+            }
+            // 计算桶索引，越过尾部则返回头部
+            index = (index + 1) % capacity;
+        }
+        // 若 key 不存在，则返回添加点的索引
+        return firstTombstone == -1 ? index : firstTombstone;
+    }
+
+    /* 查询操作 */
+    string get(int key) {
+        // 搜索 key 对应的桶索引
+        int index = findBucket(key);
+        // 若找到键值对，则返回对应 val
+        if (buckets[index] != nullptr && buckets[index] != TOMBSTONE) {
+            return buckets[index]->val;
+        }
+        // 若键值对不存在，则返回空字符串
+        return "";
+    }
+
+    /* 添加操作 */
+    void put(int key, string val) {
+        // 当负载因子超过阈值时，执行扩容
+        if (loadFactor() > loadThres) {
+            extend();
+        }
+        // 搜索 key 对应的桶索引
+        int index = findBucket(key);
+        // 若找到键值对，则覆盖 val 并返回
+        if (buckets[index] != nullptr && buckets[index] != TOMBSTONE) {
+            buckets[index]->val = val;
+            return;
+        }
+        // 若键值对不存在，则添加该键值对
+        buckets[index] = new Pair(key, val);
+        size++;
+    }
+
+    /* 删除操作 */
+    void remove(int key) {
+        // 搜索 key 对应的桶索引
+        int index = findBucket(key);
+        // 若找到键值对，则用删除标记覆盖它
+        if (buckets[index] != nullptr && buckets[index] != TOMBSTONE) {
+            delete buckets[index];
+            buckets[index] = TOMBSTONE;
+            size--;
+        }
+    }
+
+    /* 扩容哈希表 */
+    void extend() {
+        // 暂存原哈希表
+        vector<Pair *> bucketsTmp = buckets;
+        // 初始化扩容后的新哈希表
+        capacity *= extendRatio;
+        buckets = vector<Pair *>(capacity, nullptr);
+        size = 0;
+        // 将键值对从原哈希表搬运至新哈希表
+        for (Pair *pair : bucketsTmp) {
+            if (pair != nullptr && pair != TOMBSTONE) {
+                put(pair->key, pair->val);
+                delete pair;
+            }
+        }
+    }
+
+    /* 打印哈希表 */
+    void print() {
+        for (Pair *pair : buckets) {
+            if (pair == nullptr) {
+                cout << "nullptr" << endl;
+            } else if (pair == TOMBSTONE) {
+                cout << "TOMBSTONE" << endl;
+            } else {
+                cout << pair->key << " -> " << pair->val << endl;
+            }
+        }
+    }
+};
+
+/* Driver Code */
+int main() {
+    // 初始化哈希表
+    HashMapOpenAddressing hashmap;
+
+    // 添加操作
+    // 在哈希表中添加键值对 (key, val)
+    hashmap.put(12836, "小哈");
+    hashmap.put(15937, "小啰");
+    hashmap.put(16750, "小算");
+    hashmap.put(13276, "小法");
+    hashmap.put(10583, "小鸭");
+    cout << "\n添加完成后，哈希表为\nKey -> Value" << endl;
+    hashmap.print();
+
+    // 查询操作
+    // 向哈希表中输入键 key ，得到值 val
+    string name = hashmap.get(13276);
+    cout << "\n输入学号 13276 ，查询到姓名 " << name << endl;
+
+    // 删除操作
+    // 在哈希表中删除键值对 (key, val)
+    hashmap.remove(16750);
+    cout << "\n删除 16750 后，哈希表为\nKey -> Value" << endl;
+    hashmap.print();
+
+    return 0;
+}
diff --git a/chapter_hashing/simple_hash.cpp b/chapter_hashing/simple_hash.cpp
new file mode 100644
index 0000000..02b3eb7
--- /dev/null
+++ b/chapter_hashing/simple_hash.cpp
@@ -0,0 +1,66 @@
+/**
+ * File: simple_hash.cpp
+ * Created Time: 2023-06-21
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 加法哈希 */
+int addHash(string key) {
+    long long hash = 0;
+    const int MODULUS = 1000000007;
+    for (unsigned char c : key) {
+        hash = (hash + (int)c) % MODULUS;
+    }
+    return (int)hash;
+}
+
+/* 乘法哈希 */
+int mulHash(string key) {
+    long long hash = 0;
+    const int MODULUS = 1000000007;
+    for (unsigned char c : key) {
+        hash = (31 * hash + (int)c) % MODULUS;
+    }
+    return (int)hash;
+}
+
+/* 异或哈希 */
+int xorHash(string key) {
+    int hash = 0;
+    const int MODULUS = 1000000007;
+    for (unsigned char c : key) {
+        hash ^= (int)c;
+    }
+    return hash & MODULUS;
+}
+
+/* 旋转哈希 */
+int rotHash(string key) {
+    long long hash = 0;
+    const int MODULUS = 1000000007;
+    for (unsigned char c : key) {
+        hash = ((hash << 4) ^ (hash >> 28) ^ (int)c) % MODULUS;
+    }
+    return (int)hash;
+}
+
+/* Driver Code */
+int main() {
+    string key = "Hello dsad3241241dsa算123法";
+
+    int hash = addHash(key);
+    cout << "加法哈希值为 " << hash << endl;
+
+    hash = mulHash(key);
+    cout << "乘法哈希值为 " << hash << endl;
+
+    hash = xorHash(key);
+    cout << "异或哈希值为 " << hash << endl;
+
+    hash = rotHash(key);
+    cout << "旋转哈希值为 " << hash << endl;
+
+    return 0;
+}
diff --git a/chapter_heap/CMakeLists.txt b/chapter_heap/CMakeLists.txt
new file mode 100644
index 0000000..1ac33a4
--- /dev/null
+++ b/chapter_heap/CMakeLists.txt
@@ -0,0 +1,3 @@
+add_executable(heap heap.cpp)
+add_executable(my_heap my_heap.cpp)
+add_executable(top_k top_k.cpp)
diff --git a/chapter_heap/heap.cpp b/chapter_heap/heap.cpp
new file mode 100644
index 0000000..84f70bb
--- /dev/null
+++ b/chapter_heap/heap.cpp
@@ -0,0 +1,66 @@
+/**
+ * File: heap.cpp
+ * Created Time: 2023-01-19
+ * Author: LoneRanger(836253168@qq.com)
+ */
+
+#include "../utils/common.hpp"
+
+void testPush(priority_queue<int> &heap, int val) {
+    heap.push(val); // 元素入堆
+    cout << "\n元素 " << val << " 入堆后" << endl;
+    printHeap(heap);
+}
+
+void testPop(priority_queue<int> &heap) {
+    int val = heap.top();
+    heap.pop();
+    cout << "\n堆顶元素 " << val << " 出堆后" << endl;
+    printHeap(heap);
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化堆 */
+    // 初始化小顶堆
+    // priority_queue<int, vector<int>, greater<int>> minHeap;
+    // 初始化大顶堆
+    priority_queue<int, vector<int>, less<int>> maxHeap;
+
+    cout << "\n以下测试样例为大顶堆" << endl;
+
+    /* 元素入堆 */
+    testPush(maxHeap, 1);
+    testPush(maxHeap, 3);
+    testPush(maxHeap, 2);
+    testPush(maxHeap, 5);
+    testPush(maxHeap, 4);
+
+    /* 获取堆顶元素 */
+    int peek = maxHeap.top();
+    cout << "\n堆顶元素为 " << peek << endl;
+
+    /* 堆顶元素出堆 */
+    testPop(maxHeap);
+    testPop(maxHeap);
+    testPop(maxHeap);
+    testPop(maxHeap);
+    testPop(maxHeap);
+
+    /* 获取堆大小 */
+    int size = maxHeap.size();
+    cout << "\n堆元素数量为 " << size << endl;
+
+    /* 判断堆是否为空 */
+    bool isEmpty = maxHeap.empty();
+    cout << "\n堆是否为空 " << isEmpty << endl;
+
+    /* 输入列表并建堆 */
+    // 时间复杂度为 O(n) ，而非 O(nlogn)
+    vector<int> input{1, 3, 2, 5, 4};
+    priority_queue<int, vector<int>, greater<int>> minHeap(input.begin(), input.end());
+    cout << "输入列表并建立小顶堆后" << endl;
+    printHeap(minHeap);
+
+    return 0;
+}
diff --git a/chapter_heap/my_heap.cpp b/chapter_heap/my_heap.cpp
new file mode 100644
index 0000000..5e6299e
--- /dev/null
+++ b/chapter_heap/my_heap.cpp
@@ -0,0 +1,155 @@
+/**
+ * File: my_heap.cpp
+ * Created Time: 2023-02-04
+ * Author: LoneRanger (836253168@qq.com), what-is-me (whatisme@outlook.jp)
+ */
+
+#include "../utils/common.hpp"
+
+/* 大顶堆 */
+class MaxHeap {
+  private:
+    // 使用动态数组，这样无须考虑扩容问题
+    vector<int> maxHeap;
+
+    /* 获取左子节点的索引 */
+    int left(int i) {
+        return 2 * i + 1;
+    }
+
+    /* 获取右子节点的索引 */
+    int right(int i) {
+        return 2 * i + 2;
+    }
+
+    /* 获取父节点的索引 */
+    int parent(int i) {
+        return (i - 1) / 2; // 向下整除
+    }
+
+    /* 从节点 i 开始，从底至顶堆化 */
+    void siftUp(int i) {
+        while (true) {
+            // 获取节点 i 的父节点
+            int p = parent(i);
+            // 当“越过根节点”或“节点无须修复”时，结束堆化
+            if (p < 0 || maxHeap[i] <= maxHeap[p])
+                break;
+            // 交换两节点
+            swap(maxHeap[i], maxHeap[p]);
+            // 循环向上堆化
+            i = p;
+        }
+    }
+
+    /* 从节点 i 开始，从顶至底堆化 */
+    void siftDown(int i) {
+        while (true) {
+            // 判断节点 i, l, r 中值最大的节点，记为 ma
+            int l = left(i), r = right(i), ma = i;
+            if (l < size() && maxHeap[l] > maxHeap[ma])
+                ma = l;
+            if (r < size() && maxHeap[r] > maxHeap[ma])
+                ma = r;
+            // 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出
+            if (ma == i)
+                break;
+            swap(maxHeap[i], maxHeap[ma]);
+            // 循环向下堆化
+            i = ma;
+        }
+    }
+
+  public:
+    /* 构造方法，根据输入列表建堆 */
+    MaxHeap(vector<int> nums) {
+        // 将列表元素原封不动添加进堆
+        maxHeap = nums;
+        // 堆化除叶节点以外的其他所有节点
+        for (int i = parent(size() - 1); i >= 0; i--) {
+            siftDown(i);
+        }
+    }
+
+    /* 获取堆大小 */
+    int size() {
+        return maxHeap.size();
+    }
+
+    /* 判断堆是否为空 */
+    bool isEmpty() {
+        return size() == 0;
+    }
+
+    /* 访问堆顶元素 */
+    int peek() {
+        return maxHeap[0];
+    }
+
+    /* 元素入堆 */
+    void push(int val) {
+        // 添加节点
+        maxHeap.push_back(val);
+        // 从底至顶堆化
+        siftUp(size() - 1);
+    }
+
+    /* 元素出堆 */
+    void pop() {
+        // 判空处理
+        if (isEmpty()) {
+            throw out_of_range("堆为空");
+        }
+        // 交换根节点与最右叶节点（交换首元素与尾元素）
+        swap(maxHeap[0], maxHeap[size() - 1]);
+        // 删除节点
+        maxHeap.pop_back();
+        // 从顶至底堆化
+        siftDown(0);
+    }
+
+    /* 打印堆（二叉树）*/
+    void print() {
+        cout << "堆的数组表示：";
+        printVector(maxHeap);
+        cout << "堆的树状表示：" << endl;
+        TreeNode *root = vectorToTree(maxHeap);
+        printTree(root);
+        freeMemoryTree(root);
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化大顶堆 */
+    vector<int> vec{9, 8, 6, 6, 7, 5, 2, 1, 4, 3, 6, 2};
+    MaxHeap maxHeap(vec);
+    cout << "\n输入列表并建堆后" << endl;
+    maxHeap.print();
+
+    /* 获取堆顶元素 */
+    int peek = maxHeap.peek();
+    cout << "\n堆顶元素为 " << peek << endl;
+
+    /* 元素入堆 */
+    int val = 7;
+    maxHeap.push(val);
+    cout << "\n元素 " << val << " 入堆后" << endl;
+    maxHeap.print();
+
+    /* 堆顶元素出堆 */
+    peek = maxHeap.peek();
+    maxHeap.pop();
+    cout << "\n堆顶元素 " << peek << " 出堆后" << endl;
+    maxHeap.print();
+
+    /* 获取堆大小 */
+    int size = maxHeap.size();
+    cout << "\n堆元素数量为 " << size << endl;
+
+    /* 判断堆是否为空 */
+    bool isEmpty = maxHeap.isEmpty();
+    cout << "\n堆是否为空 " << isEmpty << endl;
+
+    return 0;
+}
diff --git a/chapter_heap/top_k.cpp b/chapter_heap/top_k.cpp
new file mode 100644
index 0000000..0b4b11a
--- /dev/null
+++ b/chapter_heap/top_k.cpp
@@ -0,0 +1,38 @@
+/**
+ * File: top_k.cpp
+ * Created Time: 2023-06-12
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于堆查找数组中最大的 k 个元素 */
+priority_queue<int, vector<int>, greater<int>> topKHeap(vector<int> &nums, int k) {
+    // 初始化小顶堆
+    priority_queue<int, vector<int>, greater<int>> heap;
+    // 将数组的前 k 个元素入堆
+    for (int i = 0; i < k; i++) {
+        heap.push(nums[i]);
+    }
+    // 从第 k+1 个元素开始，保持堆的长度为 k
+    for (int i = k; i < nums.size(); i++) {
+        // 若当前元素大于堆顶元素，则将堆顶元素出堆、当前元素入堆
+        if (nums[i] > heap.top()) {
+            heap.pop();
+            heap.push(nums[i]);
+        }
+    }
+    return heap;
+}
+
+// Driver Code
+int main() {
+    vector<int> nums = {1, 7, 6, 3, 2};
+    int k = 3;
+
+    priority_queue<int, vector<int>, greater<int>> res = topKHeap(nums, k);
+    cout << "最大的 " << k << " 个元素为: ";
+    printHeap(res);
+
+    return 0;
+}
diff --git a/chapter_searching/CMakeLists.txt b/chapter_searching/CMakeLists.txt
new file mode 100644
index 0000000..60a223d
--- /dev/null
+++ b/chapter_searching/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_executable(binary_search binary_search.cpp)
+add_executable(binary_search_insertion binary_search_insertion.cpp)
+add_executable(binary_search_edge binary_search_edge.cpp)
+add_executable(two_sum two_sum.cpp)
diff --git a/chapter_searching/binary_search.cpp b/chapter_searching/binary_search.cpp
new file mode 100644
index 0000000..a36670e
--- /dev/null
+++ b/chapter_searching/binary_search.cpp
@@ -0,0 +1,59 @@
+/**
+ * File: binary_search.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 二分查找（双闭区间） */
+int binarySearch(vector<int> &nums, int target) {
+    // 初始化双闭区间 [0, n-1] ，即 i, j 分别指向数组首元素、尾元素
+    int i = 0, j = nums.size() - 1;
+    // 循环，当搜索区间为空时跳出（当 i > j 时为空）
+    while (i <= j) {
+        int m = i + (j - i) / 2; // 计算中点索引 m
+        if (nums[m] < target)    // 此情况说明 target 在区间 [m+1, j] 中
+            i = m + 1;
+        else if (nums[m] > target) // 此情况说明 target 在区间 [i, m-1] 中
+            j = m - 1;
+        else // 找到目标元素，返回其索引
+            return m;
+    }
+    // 未找到目标元素，返回 -1
+    return -1;
+}
+
+/* 二分查找（左闭右开区间） */
+int binarySearchLCRO(vector<int> &nums, int target) {
+    // 初始化左闭右开区间 [0, n) ，即 i, j 分别指向数组首元素、尾元素+1
+    int i = 0, j = nums.size();
+    // 循环，当搜索区间为空时跳出（当 i = j 时为空）
+    while (i < j) {
+        int m = i + (j - i) / 2; // 计算中点索引 m
+        if (nums[m] < target)    // 此情况说明 target 在区间 [m+1, j) 中
+            i = m + 1;
+        else if (nums[m] > target) // 此情况说明 target 在区间 [i, m) 中
+            j = m;
+        else // 找到目标元素，返回其索引
+            return m;
+    }
+    // 未找到目标元素，返回 -1
+    return -1;
+}
+
+/* Driver Code */
+int main() {
+    int target = 6;
+    vector<int> nums = {1, 3, 6, 8, 12, 15, 23, 26, 31, 35};
+
+    /* 二分查找（双闭区间） */
+    int index = binarySearch(nums, target);
+    cout << "目标元素 6 的索引 = " << index << endl;
+
+    /* 二分查找（左闭右开区间） */
+    index = binarySearchLCRO(nums, target);
+    cout << "目标元素 6 的索引 = " << index << endl;
+
+    return 0;
+}
diff --git a/chapter_searching/binary_search_edge.cpp b/chapter_searching/binary_search_edge.cpp
new file mode 100644
index 0000000..6a536c2
--- /dev/null
+++ b/chapter_searching/binary_search_edge.cpp
@@ -0,0 +1,66 @@
+/**
+ * File: binary_search_edge.cpp
+ * Created Time: 2023-08-04
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 二分查找插入点（存在重复元素） */
+int binarySearchInsertion(const vector<int> &nums, int target) {
+    int i = 0, j = nums.size() - 1; // 初始化双闭区间 [0, n-1]
+    while (i <= j) {
+        int m = i + (j - i) / 2; // 计算中点索引 m
+        if (nums[m] < target) {
+            i = m + 1; // target 在区间 [m+1, j] 中
+        } else {
+            j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中
+        }
+    }
+    // 返回插入点 i
+    return i;
+}
+
+/* 二分查找最左一个 target */
+int binarySearchLeftEdge(vector<int> &nums, int target) {
+    // 等价于查找 target 的插入点
+    int i = binarySearchInsertion(nums, target);
+    // 未找到 target ，返回 -1
+    if (i == nums.size() || nums[i] != target) {
+        return -1;
+    }
+    // 找到 target ，返回索引 i
+    return i;
+}
+
+/* 二分查找最右一个 target */
+int binarySearchRightEdge(vector<int> &nums, int target) {
+    // 转化为查找最左一个 target + 1
+    int i = binarySearchInsertion(nums, target + 1);
+    // j 指向最右一个 target ，i 指向首个大于 target 的元素
+    int j = i - 1;
+    // 未找到 target ，返回 -1
+    if (j == -1 || nums[j] != target) {
+        return -1;
+    }
+    // 找到 target ，返回索引 j
+    return j;
+}
+
+/* Driver Code */
+int main() {
+    // 包含重复元素的数组
+    vector<int> nums = {1, 3, 6, 6, 6, 6, 6, 10, 12, 15};
+    cout << "\n数组 nums = ";
+    printVector(nums);
+
+    // 二分查找左边界和右边界
+    for (int target : {6, 7}) {
+        int index = binarySearchLeftEdge(nums, target);
+        cout << "最左一个元素 " << target << " 的索引为 " << index << endl;
+        index = binarySearchRightEdge(nums, target);
+        cout << "最右一个元素 " << target << " 的索引为 " << index << endl;
+    }
+
+    return 0;
+}
diff --git a/chapter_searching/binary_search_insertion.cpp b/chapter_searching/binary_search_insertion.cpp
new file mode 100644
index 0000000..f2fd15a
--- /dev/null
+++ b/chapter_searching/binary_search_insertion.cpp
@@ -0,0 +1,66 @@
+/**
+ * File: binary_search_insertion.cpp
+ * Created Time: 2023-08-04
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 二分查找插入点（无重复元素） */
+int binarySearchInsertionSimple(vector<int> &nums, int target) {
+    int i = 0, j = nums.size() - 1; // 初始化双闭区间 [0, n-1]
+    while (i <= j) {
+        int m = i + (j - i) / 2; // 计算中点索引 m
+        if (nums[m] < target) {
+            i = m + 1; // target 在区间 [m+1, j] 中
+        } else if (nums[m] > target) {
+            j = m - 1; // target 在区间 [i, m-1] 中
+        } else {
+            return m; // 找到 target ，返回插入点 m
+        }
+    }
+    // 未找到 target ，返回插入点 i
+    return i;
+}
+
+/* 二分查找插入点（存在重复元素） */
+int binarySearchInsertion(vector<int> &nums, int target) {
+    int i = 0, j = nums.size() - 1; // 初始化双闭区间 [0, n-1]
+    while (i <= j) {
+        int m = i + (j - i) / 2; // 计算中点索引 m
+        if (nums[m] < target) {
+            i = m + 1; // target 在区间 [m+1, j] 中
+        } else if (nums[m] > target) {
+            j = m - 1; // target 在区间 [i, m-1] 中
+        } else {
+            j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中
+        }
+    }
+    // 返回插入点 i
+    return i;
+}
+
+/* Driver Code */
+int main() {
+    // 无重复元素的数组
+    vector<int> nums = {1, 3, 6, 8, 12, 15, 23, 26, 31, 35};
+    cout << "\n数组 nums = ";
+    printVector(nums);
+    // 二分查找插入点
+    for (int target : {6, 9}) {
+        int index = binarySearchInsertionSimple(nums, target);
+        cout << "元素 " << target << " 的插入点的索引为 " << index << endl;
+    }
+
+    // 包含重复元素的数组
+    nums = {1, 3, 6, 6, 6, 6, 6, 10, 12, 15};
+    cout << "\n数组 nums = ";
+    printVector(nums);
+    // 二分查找插入点
+    for (int target : {2, 6, 20}) {
+        int index = binarySearchInsertion(nums, target);
+        cout << "元素 " << target << " 的插入点的索引为 " << index << endl;
+    }
+
+    return 0;
+}
diff --git a/chapter_searching/hashing_search.cpp b/chapter_searching/hashing_search.cpp
new file mode 100644
index 0000000..4bd6bd5
--- /dev/null
+++ b/chapter_searching/hashing_search.cpp
@@ -0,0 +1,53 @@
+/**
+ * File: hashing_search.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 哈希查找（数组） */
+int hashingSearchArray(unordered_map<int, int> map, int target) {
+    // 哈希表的 key: 目标元素，value: 索引
+    // 若哈希表中无此 key ，返回 -1
+    if (map.find(target) == map.end())
+        return -1;
+    return map[target];
+}
+
+/* 哈希查找（链表） */
+ListNode *hashingSearchLinkedList(unordered_map<int, ListNode *> map, int target) {
+    // 哈希表的 key: 目标节点值，value: 节点对象
+    // 若哈希表中无此 key ，返回 nullptr
+    if (map.find(target) == map.end())
+        return nullptr;
+    return map[target];
+}
+
+/* Driver Code */
+int main() {
+    int target = 3;
+
+    /* 哈希查找（数组） */
+    vector<int> nums = {1, 5, 3, 2, 4, 7, 5, 9, 10, 8};
+    // 初始化哈希表
+    unordered_map<int, int> map;
+    for (int i = 0; i < nums.size(); i++) {
+        map[nums[i]] = i; // key: 元素，value: 索引
+    }
+    int index = hashingSearchArray(map, target);
+    cout << "目标元素 3 的索引 = " << index << endl;
+
+    /* 哈希查找（链表） */
+    ListNode *head = vecToLinkedList(nums);
+    // 初始化哈希表
+    unordered_map<int, ListNode *> map1;
+    while (head != nullptr) {
+        map1[head->val] = head; // key: 节点值，value: 节点
+        head = head->next;
+    }
+    ListNode *node = hashingSearchLinkedList(map1, target);
+    cout << "目标节点值 3 的对应节点对象为 " << node << endl;
+
+    return 0;
+}
diff --git a/chapter_searching/linear_search.cpp b/chapter_searching/linear_search.cpp
new file mode 100644
index 0000000..fb4aece
--- /dev/null
+++ b/chapter_searching/linear_search.cpp
@@ -0,0 +1,49 @@
+/**
+ * File: linear_search.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 线性查找（数组） */
+int linearSearchArray(vector<int> &nums, int target) {
+    // 遍历数组
+    for (int i = 0; i < nums.size(); i++) {
+        // 找到目标元素，返回其索引
+        if (nums[i] == target)
+            return i;
+    }
+    // 未找到目标元素，返回 -1
+    return -1;
+}
+
+/* 线性查找（链表） */
+ListNode *linearSearchLinkedList(ListNode *head, int target) {
+    // 遍历链表
+    while (head != nullptr) {
+        // 找到目标节点，返回之
+        if (head->val == target)
+            return head;
+        head = head->next;
+    }
+    // 未找到目标节点，返回 nullptr
+    return nullptr;
+}
+
+/* Driver Code */
+int main() {
+    int target = 3;
+
+    /* 在数组中执行线性查找 */
+    vector<int> nums = {1, 5, 3, 2, 4, 7, 5, 9, 10, 8};
+    int index = linearSearchArray(nums, target);
+    cout << "目标元素 3 的索引 = " << index << endl;
+
+    /* 在链表中执行线性查找 */
+    ListNode *head = vecToLinkedList(nums);
+    ListNode *node = linearSearchLinkedList(head, target);
+    cout << "目标节点值 3 的对应节点对象为 " << node << endl;
+
+    return 0;
+}
diff --git a/chapter_searching/two_sum.cpp b/chapter_searching/two_sum.cpp
new file mode 100644
index 0000000..eba46c1
--- /dev/null
+++ b/chapter_searching/two_sum.cpp
@@ -0,0 +1,54 @@
+/**
+ * File: two_sum.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 方法一：暴力枚举 */
+vector<int> twoSumBruteForce(vector<int> &nums, int target) {
+    int size = nums.size();
+    // 两层循环，时间复杂度为 O(n^2)
+    for (int i = 0; i < size - 1; i++) {
+        for (int j = i + 1; j < size; j++) {
+            if (nums[i] + nums[j] == target)
+                return {i, j};
+        }
+    }
+    return {};
+}
+
+/* 方法二：辅助哈希表 */
+vector<int> twoSumHashTable(vector<int> &nums, int target) {
+    int size = nums.size();
+    // 辅助哈希表，空间复杂度为 O(n)
+    unordered_map<int, int> dic;
+    // 单层循环，时间复杂度为 O(n)
+    for (int i = 0; i < size; i++) {
+        if (dic.find(target - nums[i]) != dic.end()) {
+            return {dic[target - nums[i]], i};
+        }
+        dic.emplace(nums[i], i);
+    }
+    return {};
+}
+
+/* Driver Code */
+int main() {
+    // ======= Test Case =======
+    vector<int> nums = {2, 7, 11, 15};
+    int target = 13;
+
+    // ====== Driver Code ======
+    // 方法一
+    vector<int> res = twoSumBruteForce(nums, target);
+    cout << "方法一 res = ";
+    printVector(res);
+    // 方法二
+    res = twoSumHashTable(nums, target);
+    cout << "方法二 res = ";
+    printVector(res);
+
+    return 0;
+}
diff --git a/chapter_sorting/CMakeLists.txt b/chapter_sorting/CMakeLists.txt
new file mode 100644
index 0000000..e6347cf
--- /dev/null
+++ b/chapter_sorting/CMakeLists.txt
@@ -0,0 +1,6 @@
+add_executable(selection_sort selection_sort.cpp)
+add_executable(bubble_sort bubble_sort.cpp)
+add_executable(insertion_sort insertion_sort.cpp)
+add_executable(merge_sort merge_sort.cpp)
+add_executable(quick_sort quick_sort.cpp)
+add_executable(heap_sort heap_sort.cpp)
\ No newline at end of file
diff --git a/chapter_sorting/bubble_sort.cpp b/chapter_sorting/bubble_sort.cpp
new file mode 100644
index 0000000..a64d239
--- /dev/null
+++ b/chapter_sorting/bubble_sort.cpp
@@ -0,0 +1,56 @@
+/**
+ * File: bubble_sort.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 冒泡排序 */
+void bubbleSort(vector<int> &nums) {
+    // 外循环：未排序区间为 [0, i]
+    for (int i = nums.size() - 1; i > 0; i--) {
+        // 内循环：将未排序区间 [0, i] 中的最大元素交换至该区间的最右端
+        for (int j = 0; j < i; j++) {
+            if (nums[j] > nums[j + 1]) {
+                // 交换 nums[j] 与 nums[j + 1]
+                // 这里使用了 std::swap() 函数
+                swap(nums[j], nums[j + 1]);
+            }
+        }
+    }
+}
+
+/* 冒泡排序（标志优化）*/
+void bubbleSortWithFlag(vector<int> &nums) {
+    // 外循环：未排序区间为 [0, i]
+    for (int i = nums.size() - 1; i > 0; i--) {
+        bool flag = false; // 初始化标志位
+        // 内循环：将未排序区间 [0, i] 中的最大元素交换至该区间的最右端
+        for (int j = 0; j < i; j++) {
+            if (nums[j] > nums[j + 1]) {
+                // 交换 nums[j] 与 nums[j + 1]
+                // 这里使用了 std::swap() 函数
+                swap(nums[j], nums[j + 1]);
+                flag = true; // 记录交换元素
+            }
+        }
+        if (!flag)
+            break; // 此轮“冒泡”未交换任何元素，直接跳出
+    }
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {4, 1, 3, 1, 5, 2};
+    bubbleSort(nums);
+    cout << "冒泡排序完成后 nums = ";
+    printVector(nums);
+
+    vector<int> nums1 = {4, 1, 3, 1, 5, 2};
+    bubbleSortWithFlag(nums1);
+    cout << "冒泡排序完成后 nums1 = ";
+    printVector(nums1);
+
+    return 0;
+}
diff --git a/chapter_sorting/bucket_sort.cpp b/chapter_sorting/bucket_sort.cpp
new file mode 100644
index 0000000..42be5c3
--- /dev/null
+++ b/chapter_sorting/bucket_sort.cpp
@@ -0,0 +1,44 @@
+/**
+ * File: bucket_sort.cpp
+ * Created Time: 2023-03-30
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 桶排序 */
+void bucketSort(vector<float> &nums) {
+    // 初始化 k = n/2 个桶，预期向每个桶分配 2 个元素
+    int k = nums.size() / 2;
+    vector<vector<float>> buckets(k);
+    // 1. 将数组元素分配到各个桶中
+    for (float num : nums) {
+        // 输入数据范围为 [0, 1)，使用 num * k 映射到索引范围 [0, k-1]
+        int i = num * k;
+        // 将 num 添加进桶 bucket_idx
+        buckets[i].push_back(num);
+    }
+    // 2. 对各个桶执行排序
+    for (vector<float> &bucket : buckets) {
+        // 使用内置排序函数，也可以替换成其他排序算法
+        sort(bucket.begin(), bucket.end());
+    }
+    // 3. 遍历桶合并结果
+    int i = 0;
+    for (vector<float> &bucket : buckets) {
+        for (float num : bucket) {
+            nums[i++] = num;
+        }
+    }
+}
+
+/* Driver Code */
+int main() {
+    // 设输入数据为浮点数，范围为 [0, 1)
+    vector<float> nums = {0.49f, 0.96f, 0.82f, 0.09f, 0.57f, 0.43f, 0.91f, 0.75f, 0.15f, 0.37f};
+    bucketSort(nums);
+    cout << "桶排序完成后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_sorting/counting_sort.cpp b/chapter_sorting/counting_sort.cpp
new file mode 100644
index 0000000..824ef0a
--- /dev/null
+++ b/chapter_sorting/counting_sort.cpp
@@ -0,0 +1,77 @@
+/**
+ * File: counting_sort.cpp
+ * Created Time: 2023-03-17
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 计数排序 */
+// 简单实现，无法用于排序对象
+void countingSortNaive(vector<int> &nums) {
+    // 1. 统计数组最大元素 m
+    int m = 0;
+    for (int num : nums) {
+        m = max(m, num);
+    }
+    // 2. 统计各数字的出现次数
+    // counter[num] 代表 num 的出现次数
+    vector<int> counter(m + 1, 0);
+    for (int num : nums) {
+        counter[num]++;
+    }
+    // 3. 遍历 counter ，将各元素填入原数组 nums
+    int i = 0;
+    for (int num = 0; num < m + 1; num++) {
+        for (int j = 0; j < counter[num]; j++, i++) {
+            nums[i] = num;
+        }
+    }
+}
+
+/* 计数排序 */
+// 完整实现，可排序对象，并且是稳定排序
+void countingSort(vector<int> &nums) {
+    // 1. 统计数组最大元素 m
+    int m = 0;
+    for (int num : nums) {
+        m = max(m, num);
+    }
+    // 2. 统计各数字的出现次数
+    // counter[num] 代表 num 的出现次数
+    vector<int> counter(m + 1, 0);
+    for (int num : nums) {
+        counter[num]++;
+    }
+    // 3. 求 counter 的前缀和，将“出现次数”转换为“尾索引”
+    // 即 counter[num]-1 是 num 在 res 中最后一次出现的索引
+    for (int i = 0; i < m; i++) {
+        counter[i + 1] += counter[i];
+    }
+    // 4. 倒序遍历 nums ，将各元素填入结果数组 res
+    // 初始化数组 res 用于记录结果
+    int n = nums.size();
+    vector<int> res(n);
+    for (int i = n - 1; i >= 0; i--) {
+        int num = nums[i];
+        res[counter[num] - 1] = num; // 将 num 放置到对应索引处
+        counter[num]--;              // 令前缀和自减 1 ，得到下次放置 num 的索引
+    }
+    // 使用结果数组 res 覆盖原数组 nums
+    nums = res;
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {1, 0, 1, 2, 0, 4, 0, 2, 2, 4};
+    countingSortNaive(nums);
+    cout << "计数排序（无法排序对象）完成后 nums = ";
+    printVector(nums);
+
+    vector<int> nums1 = {1, 0, 1, 2, 0, 4, 0, 2, 2, 4};
+    countingSort(nums1);
+    cout << "计数排序完成后 nums1 = ";
+    printVector(nums1);
+
+    return 0;
+}
diff --git a/chapter_sorting/heap_sort.cpp b/chapter_sorting/heap_sort.cpp
new file mode 100644
index 0000000..1e568b8
--- /dev/null
+++ b/chapter_sorting/heap_sort.cpp
@@ -0,0 +1,54 @@
+/**
+ * File: heap_sort.cpp
+ * Created Time: 2023-05-26
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 堆的长度为 n ，从节点 i 开始，从顶至底堆化 */
+void siftDown(vector<int> &nums, int n, int i) {
+    while (true) {
+        // 判断节点 i, l, r 中值最大的节点，记为 ma
+        int l = 2 * i + 1;
+        int r = 2 * i + 2;
+        int ma = i;
+        if (l < n && nums[l] > nums[ma])
+            ma = l;
+        if (r < n && nums[r] > nums[ma])
+            ma = r;
+        // 若节点 i 最大或索引 l, r 越界，则无须继续堆化，跳出
+        if (ma == i) {
+            break;
+        }
+        // 交换两节点
+        swap(nums[i], nums[ma]);
+        // 循环向下堆化
+        i = ma;
+    }
+}
+
+/* 堆排序 */
+void heapSort(vector<int> &nums) {
+    // 建堆操作：堆化除叶节点以外的其他所有节点
+    for (int i = nums.size() / 2 - 1; i >= 0; --i) {
+        siftDown(nums, nums.size(), i);
+    }
+    // 从堆中提取最大元素，循环 n-1 轮
+    for (int i = nums.size() - 1; i > 0; --i) {
+        // 交换根节点与最右叶节点（交换首元素与尾元素）
+        swap(nums[0], nums[i]);
+        // 以根节点为起点，从顶至底进行堆化
+        siftDown(nums, i, 0);
+    }
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {4, 1, 3, 1, 5, 2};
+    heapSort(nums);
+    cout << "堆排序完成后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_sorting/insertion_sort.cpp b/chapter_sorting/insertion_sort.cpp
new file mode 100644
index 0000000..d9ea719
--- /dev/null
+++ b/chapter_sorting/insertion_sort.cpp
@@ -0,0 +1,31 @@
+/**
+ * File: insertion_sort.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 插入排序 */
+void insertionSort(vector<int> &nums) {
+    // 外循环：已排序元素数量为 1, 2, ..., n
+    for (int i = 1; i < nums.size(); i++) {
+        int base = nums[i], j = i - 1;
+        // 内循环：将 base 插入到已排序部分的正确位置
+        while (j >= 0 && nums[j] > base) {
+            nums[j + 1] = nums[j]; // 将 nums[j] 向右移动一位
+            j--;
+        }
+        nums[j + 1] = base; // 将 base 赋值到正确位置
+    }
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {4, 1, 3, 1, 5, 2};
+    insertionSort(nums);
+    cout << "插入排序完成后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_sorting/merge_sort.cpp b/chapter_sorting/merge_sort.cpp
new file mode 100644
index 0000000..98a2795
--- /dev/null
+++ b/chapter_sorting/merge_sort.cpp
@@ -0,0 +1,58 @@
+/**
+ * File: merge_sort.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 合并左子数组和右子数组 */
+void merge(vector<int> &nums, int left, int mid, int right) {
+    // 左子数组区间为 [left, mid], 右子数组区间为 [mid+1, right]
+    // 创建一个临时数组 tmp ，用于存放合并后的结果
+    vector<int> tmp(right - left + 1);
+    // 初始化左子数组和右子数组的起始索引
+    int i = left, j = mid + 1, k = 0;
+    // 当左右子数组都还有元素时，进行比较并将较小的元素复制到临时数组中
+    while (i <= mid && j <= right) {
+        if (nums[i] <= nums[j])
+            tmp[k++] = nums[i++];
+        else
+            tmp[k++] = nums[j++];
+    }
+    // 将左子数组和右子数组的剩余元素复制到临时数组中
+    while (i <= mid) {
+        tmp[k++] = nums[i++];
+    }
+    while (j <= right) {
+        tmp[k++] = nums[j++];
+    }
+    // 将临时数组 tmp 中的元素复制回原数组 nums 的对应区间
+    for (k = 0; k < tmp.size(); k++) {
+        nums[left + k] = tmp[k];
+    }
+}
+
+/* 归并排序 */
+void mergeSort(vector<int> &nums, int left, int right) {
+    // 终止条件
+    if (left >= right)
+        return; // 当子数组长度为 1 时终止递归
+    // 划分阶段
+    int mid = (left + right) / 2;    // 计算中点
+    mergeSort(nums, left, mid);      // 递归左子数组
+    mergeSort(nums, mid + 1, right); // 递归右子数组
+    // 合并阶段
+    merge(nums, left, mid, right);
+}
+
+/* Driver Code */
+int main() {
+    /* 归并排序 */
+    vector<int> nums = {7, 3, 2, 6, 0, 1, 5, 4};
+    mergeSort(nums, 0, nums.size() - 1);
+    cout << "归并排序完成后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_sorting/quick_sort.cpp b/chapter_sorting/quick_sort.cpp
new file mode 100644
index 0000000..32d3fb4
--- /dev/null
+++ b/chapter_sorting/quick_sort.cpp
@@ -0,0 +1,168 @@
+/**
+ * File: quick_sort.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 快速排序类 */
+class QuickSort {
+  private:
+    /* 元素交换 */
+    static void swap(vector<int> &nums, int i, int j) {
+        int tmp = nums[i];
+        nums[i] = nums[j];
+        nums[j] = tmp;
+    }
+
+    /* 哨兵划分 */
+    static int partition(vector<int> &nums, int left, int right) {
+        // 以 nums[left] 为基准数
+        int i = left, j = right;
+        while (i < j) {
+            while (i < j && nums[j] >= nums[left])
+                j--; // 从右向左找首个小于基准数的元素
+            while (i < j && nums[i] <= nums[left])
+                i++;          // 从左向右找首个大于基准数的元素
+            swap(nums, i, j); // 交换这两个元素
+        }
+        swap(nums, i, left); // 将基准数交换至两子数组的分界线
+        return i;            // 返回基准数的索引
+    }
+
+  public:
+    /* 快速排序 */
+    static void quickSort(vector<int> &nums, int left, int right) {
+        // 子数组长度为 1 时终止递归
+        if (left >= right)
+            return;
+        // 哨兵划分
+        int pivot = partition(nums, left, right);
+        // 递归左子数组、右子数组
+        quickSort(nums, left, pivot - 1);
+        quickSort(nums, pivot + 1, right);
+    }
+};
+
+/* 快速排序类（中位基准数优化） */
+class QuickSortMedian {
+  private:
+    /* 元素交换 */
+    static void swap(vector<int> &nums, int i, int j) {
+        int tmp = nums[i];
+        nums[i] = nums[j];
+        nums[j] = tmp;
+    }
+
+    /* 选取三个候选元素的中位数 */
+    static int medianThree(vector<int> &nums, int left, int mid, int right) {
+        // 此处使用异或运算来简化代码
+        // 异或规则为 0 ^ 0 = 1 ^ 1 = 0, 0 ^ 1 = 1 ^ 0 = 1
+        if ((nums[left] < nums[mid]) ^ (nums[left] < nums[right]))
+            return left;
+        else if ((nums[mid] < nums[left]) ^ (nums[mid] < nums[right]))
+            return mid;
+        else
+            return right;
+    }
+
+    /* 哨兵划分（三数取中值） */
+    static int partition(vector<int> &nums, int left, int right) {
+        // 选取三个候选元素的中位数
+        int med = medianThree(nums, left, (left + right) / 2, right);
+        // 将中位数交换至数组最左端
+        swap(nums, left, med);
+        // 以 nums[left] 为基准数
+        int i = left, j = right;
+        while (i < j) {
+            while (i < j && nums[j] >= nums[left])
+                j--; // 从右向左找首个小于基准数的元素
+            while (i < j && nums[i] <= nums[left])
+                i++;          // 从左向右找首个大于基准数的元素
+            swap(nums, i, j); // 交换这两个元素
+        }
+        swap(nums, i, left); // 将基准数交换至两子数组的分界线
+        return i;            // 返回基准数的索引
+    }
+
+  public:
+    /* 快速排序 */
+    static void quickSort(vector<int> &nums, int left, int right) {
+        // 子数组长度为 1 时终止递归
+        if (left >= right)
+            return;
+        // 哨兵划分
+        int pivot = partition(nums, left, right);
+        // 递归左子数组、右子数组
+        quickSort(nums, left, pivot - 1);
+        quickSort(nums, pivot + 1, right);
+    }
+};
+
+/* 快速排序类（尾递归优化） */
+class QuickSortTailCall {
+  private:
+    /* 元素交换 */
+    static void swap(vector<int> &nums, int i, int j) {
+        int tmp = nums[i];
+        nums[i] = nums[j];
+        nums[j] = tmp;
+    }
+
+    /* 哨兵划分 */
+    static int partition(vector<int> &nums, int left, int right) {
+        // 以 nums[left] 为基准数
+        int i = left, j = right;
+        while (i < j) {
+            while (i < j && nums[j] >= nums[left])
+                j--; // 从右向左找首个小于基准数的元素
+            while (i < j && nums[i] <= nums[left])
+                i++;          // 从左向右找首个大于基准数的元素
+            swap(nums, i, j); // 交换这两个元素
+        }
+        swap(nums, i, left); // 将基准数交换至两子数组的分界线
+        return i;            // 返回基准数的索引
+    }
+
+  public:
+    /* 快速排序（尾递归优化） */
+    static void quickSort(vector<int> &nums, int left, int right) {
+        // 子数组长度为 1 时终止
+        while (left < right) {
+            // 哨兵划分操作
+            int pivot = partition(nums, left, right);
+            // 对两个子数组中较短的那个执行快速排序
+            if (pivot - left < right - pivot) {
+                quickSort(nums, left, pivot - 1); // 递归排序左子数组
+                left = pivot + 1;                 // 剩余未排序区间为 [pivot + 1, right]
+            } else {
+                quickSort(nums, pivot + 1, right); // 递归排序右子数组
+                right = pivot - 1;                 // 剩余未排序区间为 [left, pivot - 1]
+            }
+        }
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 快速排序 */
+    vector<int> nums{2, 4, 1, 0, 3, 5};
+    QuickSort::quickSort(nums, 0, nums.size() - 1);
+    cout << "快速排序完成后 nums = ";
+    printVector(nums);
+
+    /* 快速排序（中位基准数优化） */
+    vector<int> nums1 = {2, 4, 1, 0, 3, 5};
+    QuickSortMedian::quickSort(nums1, 0, nums1.size() - 1);
+    cout << "快速排序（中位基准数优化）完成后 nums = ";
+    printVector(nums);
+
+    /* 快速排序（尾递归优化） */
+    vector<int> nums2 = {2, 4, 1, 0, 3, 5};
+    QuickSortTailCall::quickSort(nums2, 0, nums2.size() - 1);
+    cout << "快速排序（尾递归优化）完成后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_sorting/radix_sort.cpp b/chapter_sorting/radix_sort.cpp
new file mode 100644
index 0000000..ef4ce40
--- /dev/null
+++ b/chapter_sorting/radix_sort.cpp
@@ -0,0 +1,65 @@
+/**
+ * File: radix_sort.cpp
+ * Created Time: 2023-03-26
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 获取元素 num 的第 k 位，其中 exp = 10^(k-1) */
+int digit(int num, int exp) {
+    // 传入 exp 而非 k 可以避免在此重复执行昂贵的次方计算
+    return (num / exp) % 10;
+}
+
+/* 计数排序（根据 nums 第 k 位排序） */
+void countingSortDigit(vector<int> &nums, int exp) {
+    // 十进制的位范围为 0~9 ，因此需要长度为 10 的桶数组
+    vector<int> counter(10, 0);
+    int n = nums.size();
+    // 统计 0~9 各数字的出现次数
+    for (int i = 0; i < n; i++) {
+        int d = digit(nums[i], exp); // 获取 nums[i] 第 k 位，记为 d
+        counter[d]++;                // 统计数字 d 的出现次数
+    }
+    // 求前缀和，将“出现个数”转换为“数组索引”
+    for (int i = 1; i < 10; i++) {
+        counter[i] += counter[i - 1];
+    }
+    // 倒序遍历，根据桶内统计结果，将各元素填入 res
+    vector<int> res(n, 0);
+    for (int i = n - 1; i >= 0; i--) {
+        int d = digit(nums[i], exp);
+        int j = counter[d] - 1; // 获取 d 在数组中的索引 j
+        res[j] = nums[i];       // 将当前元素填入索引 j
+        counter[d]--;           // 将 d 的数量减 1
+    }
+    // 使用结果覆盖原数组 nums
+    for (int i = 0; i < n; i++)
+        nums[i] = res[i];
+}
+
+/* 基数排序 */
+void radixSort(vector<int> &nums) {
+    // 获取数组的最大元素，用于判断最大位数
+    int m = *max_element(nums.begin(), nums.end());
+    // 按照从低位到高位的顺序遍历
+    for (int exp = 1; exp <= m; exp *= 10)
+        // 对数组元素的第 k 位执行计数排序
+        // k = 1 -> exp = 1
+        // k = 2 -> exp = 10
+        // 即 exp = 10^(k-1)
+        countingSortDigit(nums, exp);
+}
+
+/* Driver Code */
+int main() {
+    // 基数排序
+    vector<int> nums = {10546151, 35663510, 42865989, 34862445, 81883077,
+                        88906420, 72429244, 30524779, 82060337, 63832996};
+    radixSort(nums);
+    cout << "基数排序完成后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_sorting/selection_sort.cpp b/chapter_sorting/selection_sort.cpp
new file mode 100644
index 0000000..027d2ac
--- /dev/null
+++ b/chapter_sorting/selection_sort.cpp
@@ -0,0 +1,34 @@
+/**
+ * File: selection_sort.cpp
+ * Created Time: 2023-05-23
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 选择排序 */
+void selectionSort(vector<int> &nums) {
+    int n = nums.size();
+    // 外循环：未排序区间为 [i, n-1]
+    for (int i = 0; i < n - 1; i++) {
+        // 内循环：找到未排序区间内的最小元素
+        int k = i;
+        for (int j = i + 1; j < n; j++) {
+            if (nums[j] < nums[k])
+                k = j; // 记录最小元素的索引
+        }
+        // 将该最小元素与未排序区间的首个元素交换
+        swap(nums[i], nums[k]);
+    }
+}
+
+/* Driver Code */
+int main() {
+    vector<int> nums = {4, 1, 3, 1, 5, 2};
+    selectionSort(nums);
+
+    cout << "选择排序完成后 nums = ";
+    printVector(nums);
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/CMakeLists.txt b/chapter_stack_and_queue/CMakeLists.txt
new file mode 100644
index 0000000..b55878a
--- /dev/null
+++ b/chapter_stack_and_queue/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_executable(array_deque array_deque.cpp)
+add_executable(array_queue array_queue.cpp)
+add_executable(array_stack array_stack.cpp)
+add_executable(deque deque.cpp)
+add_executable(linkedlist_deque linkedlist_deque.cpp)
+add_executable(linkedlist_queue linkedlist_queue.cpp)
+add_executable(linkedlist_stack linkedlist_stack.cpp)
+add_executable(queue queue.cpp)
+add_executable(stack stack.cpp)
diff --git a/chapter_stack_and_queue/array_deque.cpp b/chapter_stack_and_queue/array_deque.cpp
new file mode 100644
index 0000000..00bf776
--- /dev/null
+++ b/chapter_stack_and_queue/array_deque.cpp
@@ -0,0 +1,156 @@
+/**
+ * File: array_deque.cpp
+ * Created Time: 2023-03-02
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于环形数组实现的双向队列 */
+class ArrayDeque {
+  private:
+    vector<int> nums; // 用于存储双向队列元素的数组
+    int front;        // 队首指针，指向队首元素
+    int queSize;      // 双向队列长度
+
+  public:
+    /* 构造方法 */
+    ArrayDeque(int capacity) {
+        nums.resize(capacity);
+        front = queSize = 0;
+    }
+
+    /* 获取双向队列的容量 */
+    int capacity() {
+        return nums.size();
+    }
+
+    /* 获取双向队列的长度 */
+    int size() {
+        return queSize;
+    }
+
+    /* 判断双向队列是否为空 */
+    bool isEmpty() {
+        return queSize == 0;
+    }
+
+    /* 计算环形数组索引 */
+    int index(int i) {
+        // 通过取余操作实现数组首尾相连
+        // 当 i 越过数组尾部后，回到头部
+        // 当 i 越过数组头部后，回到尾部
+        return (i + capacity()) % capacity();
+    }
+
+    /* 队首入队 */
+    void pushFirst(int num) {
+        if (queSize == capacity()) {
+            cout << "双向队列已满" << endl;
+            return;
+        }
+        // 队首指针向左移动一位
+        // 通过取余操作实现 front 越过数组头部后回到尾部
+        front = index(front - 1);
+        // 将 num 添加至队首
+        nums[front] = num;
+        queSize++;
+    }
+
+    /* 队尾入队 */
+    void pushLast(int num) {
+        if (queSize == capacity()) {
+            cout << "双向队列已满" << endl;
+            return;
+        }
+        // 计算队尾指针，指向队尾索引 + 1
+        int rear = index(front + queSize);
+        // 将 num 添加至队尾
+        nums[rear] = num;
+        queSize++;
+    }
+
+    /* 队首出队 */
+    int popFirst() {
+        int num = peekFirst();
+        // 队首指针向后移动一位
+        front = index(front + 1);
+        queSize--;
+        return num;
+    }
+
+    /* 队尾出队 */
+    int popLast() {
+        int num = peekLast();
+        queSize--;
+        return num;
+    }
+
+    /* 访问队首元素 */
+    int peekFirst() {
+        if (isEmpty())
+            throw out_of_range("双向队列为空");
+        return nums[front];
+    }
+
+    /* 访问队尾元素 */
+    int peekLast() {
+        if (isEmpty())
+            throw out_of_range("双向队列为空");
+        // 计算尾元素索引
+        int last = index(front + queSize - 1);
+        return nums[last];
+    }
+
+    /* 返回数组用于打印 */
+    vector<int> toVector() {
+        // 仅转换有效长度范围内的列表元素
+        vector<int> res(queSize);
+        for (int i = 0, j = front; i < queSize; i++, j++) {
+            res[i] = nums[index(j)];
+        }
+        return res;
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化双向队列 */
+    ArrayDeque *deque = new ArrayDeque(10);
+    deque->pushLast(3);
+    deque->pushLast(2);
+    deque->pushLast(5);
+    cout << "双向队列 deque = ";
+    printVector(deque->toVector());
+
+    /* 访问元素 */
+    int peekFirst = deque->peekFirst();
+    cout << "队首元素 peekFirst = " << peekFirst << endl;
+    int peekLast = deque->peekLast();
+    cout << "队尾元素 peekLast = " << peekLast << endl;
+
+    /* 元素入队 */
+    deque->pushLast(4);
+    cout << "元素 4 队尾入队后 deque = ";
+    printVector(deque->toVector());
+    deque->pushFirst(1);
+    cout << "元素 1 队首入队后 deque = ";
+    printVector(deque->toVector());
+
+    /* 元素出队 */
+    int popLast = deque->popLast();
+    cout << "队尾出队元素 = " << popLast << "，队尾出队后 deque = ";
+    printVector(deque->toVector());
+    int popFirst = deque->popFirst();
+    cout << "队首出队元素 = " << popFirst << "，队首出队后 deque = ";
+    printVector(deque->toVector());
+
+    /* 获取双向队列的长度 */
+    int size = deque->size();
+    cout << "双向队列长度 size = " << size << endl;
+
+    /* 判断双向队列是否为空 */
+    bool isEmpty = deque->isEmpty();
+    cout << "双向队列是否为空 = " << boolalpha << isEmpty << endl;
+    return 0;
+}
diff --git a/chapter_stack_and_queue/array_queue.cpp b/chapter_stack_and_queue/array_queue.cpp
new file mode 100644
index 0000000..e6def13
--- /dev/null
+++ b/chapter_stack_and_queue/array_queue.cpp
@@ -0,0 +1,129 @@
+/**
+ * File: array_queue.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于环形数组实现的队列 */
+class ArrayQueue {
+  private:
+    int *nums;       // 用于存储队列元素的数组
+    int front;       // 队首指针，指向队首元素
+    int queSize;     // 队列长度
+    int queCapacity; // 队列容量
+
+  public:
+    ArrayQueue(int capacity) {
+        // 初始化数组
+        nums = new int[capacity];
+        queCapacity = capacity;
+        front = queSize = 0;
+    }
+
+    ~ArrayQueue() {
+        delete[] nums;
+    }
+
+    /* 获取队列的容量 */
+    int capacity() {
+        return queCapacity;
+    }
+
+    /* 获取队列的长度 */
+    int size() {
+        return queSize;
+    }
+
+    /* 判断队列是否为空 */
+    bool isEmpty() {
+        return size() == 0;
+    }
+
+    /* 入队 */
+    void push(int num) {
+        if (queSize == queCapacity) {
+            cout << "队列已满" << endl;
+            return;
+        }
+        // 计算队尾指针，指向队尾索引 + 1
+        // 通过取余操作实现 rear 越过数组尾部后回到头部
+        int rear = (front + queSize) % queCapacity;
+        // 将 num 添加至队尾
+        nums[rear] = num;
+        queSize++;
+    }
+
+    /* 出队 */
+    int pop() {
+        int num = peek();
+        // 队首指针向后移动一位，若越过尾部，则返回到数组头部
+        front = (front + 1) % queCapacity;
+        queSize--;
+        return num;
+    }
+
+    /* 访问队首元素 */
+    int peek() {
+        if (isEmpty())
+            throw out_of_range("队列为空");
+        return nums[front];
+    }
+
+    /* 将数组转化为 Vector 并返回 */
+    vector<int> toVector() {
+        // 仅转换有效长度范围内的列表元素
+        vector<int> arr(queSize);
+        for (int i = 0, j = front; i < queSize; i++, j++) {
+            arr[i] = nums[j % queCapacity];
+        }
+        return arr;
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化队列 */
+    int capacity = 10;
+    ArrayQueue *queue = new ArrayQueue(capacity);
+
+    /* 元素入队 */
+    queue->push(1);
+    queue->push(3);
+    queue->push(2);
+    queue->push(5);
+    queue->push(4);
+    cout << "队列 queue = ";
+    printVector(queue->toVector());
+
+    /* 访问队首元素 */
+    int peek = queue->peek();
+    cout << "队首元素 peek = " << peek << endl;
+
+    /* 元素出队 */
+    peek = queue->pop();
+    cout << "出队元素 pop = " << peek << "，出队后 queue = ";
+    printVector(queue->toVector());
+
+    /* 获取队列的长度 */
+    int size = queue->size();
+    cout << "队列长度 size = " << size << endl;
+
+    /* 判断队列是否为空 */
+    bool empty = queue->isEmpty();
+    cout << "队列是否为空 = " << empty << endl;
+
+    /* 测试环形数组 */
+    for (int i = 0; i < 10; i++) {
+        queue->push(i);
+        queue->pop();
+        cout << "第 " << i << " 轮入队 + 出队后 queue = ";
+        printVector(queue->toVector());
+    }
+
+    // 释放内存
+    delete queue;
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/array_stack.cpp b/chapter_stack_and_queue/array_stack.cpp
new file mode 100644
index 0000000..c59e076
--- /dev/null
+++ b/chapter_stack_and_queue/array_stack.cpp
@@ -0,0 +1,85 @@
+/**
+ * File: array_stack.cpp
+ * Created Time: 2022-11-28
+ * Author: qualifier1024 (2539244001@qq.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于数组实现的栈 */
+class ArrayStack {
+  private:
+    vector<int> stack;
+
+  public:
+    /* 获取栈的长度 */
+    int size() {
+        return stack.size();
+    }
+
+    /* 判断栈是否为空 */
+    bool isEmpty() {
+        return stack.size() == 0;
+    }
+
+    /* 入栈 */
+    void push(int num) {
+        stack.push_back(num);
+    }
+
+    /* 出栈 */
+    int pop() {
+        int num = top();
+        stack.pop_back();
+        return num;
+    }
+
+    /* 访问栈顶元素 */
+    int top() {
+        if (isEmpty())
+            throw out_of_range("栈为空");
+        return stack.back();
+    }
+
+    /* 返回 Vector */
+    vector<int> toVector() {
+        return stack;
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化栈 */
+    ArrayStack *stack = new ArrayStack();
+
+    /* 元素入栈 */
+    stack->push(1);
+    stack->push(3);
+    stack->push(2);
+    stack->push(5);
+    stack->push(4);
+    cout << "栈 stack = ";
+    printVector(stack->toVector());
+
+    /* 访问栈顶元素 */
+    int top = stack->top();
+    cout << "栈顶元素 top = " << top << endl;
+
+    /* 元素出栈 */
+    top = stack->pop();
+    cout << "出栈元素 pop = " << top << "，出栈后 stack = ";
+    printVector(stack->toVector());
+
+    /* 获取栈的长度 */
+    int size = stack->size();
+    cout << "栈的长度 size = " << size << endl;
+
+    /* 判断是否为空 */
+    bool empty = stack->isEmpty();
+    cout << "栈是否为空 = " << empty << endl;
+
+    // 释放内存
+    delete stack;
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/deque.cpp b/chapter_stack_and_queue/deque.cpp
new file mode 100644
index 0000000..16da9ae
--- /dev/null
+++ b/chapter_stack_and_queue/deque.cpp
@@ -0,0 +1,46 @@
+/**
+ * File: deque.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化双向队列 */
+    deque<int> deque;
+
+    /* 元素入队 */
+    deque.push_back(2);
+    deque.push_back(5);
+    deque.push_back(4);
+    deque.push_front(3);
+    deque.push_front(1);
+    cout << "双向队列 deque = ";
+    printDeque(deque);
+
+    /* 访问元素 */
+    int front = deque.front();
+    cout << "队首元素 front = " << front << endl;
+    int back = deque.back();
+    cout << "队尾元素 back = " << back << endl;
+
+    /* 元素出队 */
+    deque.pop_front();
+    cout << "队首出队元素 popFront = " << front << "，队首出队后 deque = ";
+    printDeque(deque);
+    deque.pop_back();
+    cout << "队尾出队元素 popLast = " << back << "，队尾出队后 deque = ";
+    printDeque(deque);
+
+    /* 获取双向队列的长度 */
+    int size = deque.size();
+    cout << "双向队列长度 size = " << size << endl;
+
+    /* 判断双向队列是否为空 */
+    bool empty = deque.empty();
+    cout << "双向队列是否为空 = " << empty << endl;
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/linkedlist_deque.cpp b/chapter_stack_and_queue/linkedlist_deque.cpp
new file mode 100644
index 0000000..7eea86c
--- /dev/null
+++ b/chapter_stack_and_queue/linkedlist_deque.cpp
@@ -0,0 +1,194 @@
+/**
+ * File: linkedlist_deque.cpp
+ * Created Time: 2023-03-02
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 双向链表节点 */
+struct DoublyListNode {
+    int val;              // 节点值
+    DoublyListNode *next; // 后继节点指针
+    DoublyListNode *prev; // 前驱节点指针
+    DoublyListNode(int val) : val(val), prev(nullptr), next(nullptr) {
+    }
+};
+
+/* 基于双向链表实现的双向队列 */
+class LinkedListDeque {
+  private:
+    DoublyListNode *front, *rear; // 头节点 front ，尾节点 rear
+    int queSize = 0;              // 双向队列的长度
+
+  public:
+    /* 构造方法 */
+    LinkedListDeque() : front(nullptr), rear(nullptr) {
+    }
+
+    /* 析构方法 */
+    ~LinkedListDeque() {
+        // 遍历链表删除节点，释放内存
+        DoublyListNode *pre, *cur = front;
+        while (cur != nullptr) {
+            pre = cur;
+            cur = cur->next;
+            delete pre;
+        }
+    }
+
+    /* 获取双向队列的长度 */
+    int size() {
+        return queSize;
+    }
+
+    /* 判断双向队列是否为空 */
+    bool isEmpty() {
+        return size() == 0;
+    }
+
+    /* 入队操作 */
+    void push(int num, bool isFront) {
+        DoublyListNode *node = new DoublyListNode(num);
+        // 若链表为空，则令 front 和 rear 都指向 node
+        if (isEmpty())
+            front = rear = node;
+        // 队首入队操作
+        else if (isFront) {
+            // 将 node 添加至链表头部
+            front->prev = node;
+            node->next = front;
+            front = node; // 更新头节点
+        // 队尾入队操作
+        } else {
+            // 将 node 添加至链表尾部
+            rear->next = node;
+            node->prev = rear;
+            rear = node; // 更新尾节点
+        }
+        queSize++; // 更新队列长度
+    }
+
+    /* 队首入队 */
+    void pushFirst(int num) {
+        push(num, true);
+    }
+
+    /* 队尾入队 */
+    void pushLast(int num) {
+        push(num, false);
+    }
+
+    /* 出队操作 */
+    int pop(bool isFront) {
+        if (isEmpty())
+            throw out_of_range("队列为空");
+        int val;
+        // 队首出队操作
+        if (isFront) {
+            val = front->val; // 暂存头节点值
+            // 删除头节点
+            DoublyListNode *fNext = front->next;
+            if (fNext != nullptr) {
+                fNext->prev = nullptr;
+                front->next = nullptr;
+            }
+            delete front;
+            front = fNext; // 更新头节点
+        // 队尾出队操作
+        } else {
+            val = rear->val; // 暂存尾节点值
+            // 删除尾节点
+            DoublyListNode *rPrev = rear->prev;
+            if (rPrev != nullptr) {
+                rPrev->next = nullptr;
+                rear->prev = nullptr;
+            }
+            delete rear;
+            rear = rPrev; // 更新尾节点
+        }
+        queSize--; // 更新队列长度
+        return val;
+    }
+
+    /* 队首出队 */
+    int popFirst() {
+        return pop(true);
+    }
+
+    /* 队尾出队 */
+    int popLast() {
+        return pop(false);
+    }
+
+    /* 访问队首元素 */
+    int peekFirst() {
+        if (isEmpty())
+            throw out_of_range("双向队列为空");
+        return front->val;
+    }
+
+    /* 访问队尾元素 */
+    int peekLast() {
+        if (isEmpty())
+            throw out_of_range("双向队列为空");
+        return rear->val;
+    }
+
+    /* 返回数组用于打印 */
+    vector<int> toVector() {
+        DoublyListNode *node = front;
+        vector<int> res(size());
+        for (int i = 0; i < res.size(); i++) {
+            res[i] = node->val;
+            node = node->next;
+        }
+        return res;
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化双向队列 */
+    LinkedListDeque *deque = new LinkedListDeque();
+    deque->pushLast(3);
+    deque->pushLast(2);
+    deque->pushLast(5);
+    cout << "双向队列 deque = ";
+    printVector(deque->toVector());
+
+    /* 访问元素 */
+    int peekFirst = deque->peekFirst();
+    cout << "队首元素 peekFirst = " << peekFirst << endl;
+    int peekLast = deque->peekLast();
+    cout << "队尾元素 peekLast = " << peekLast << endl;
+
+    /* 元素入队 */
+    deque->pushLast(4);
+    cout << "元素 4 队尾入队后 deque =";
+    printVector(deque->toVector());
+    deque->pushFirst(1);
+    cout << "元素 1 队首入队后 deque = ";
+    printVector(deque->toVector());
+
+    /* 元素出队 */
+    int popLast = deque->popLast();
+    cout << "队尾出队元素 = " << popLast << "，队尾出队后 deque = ";
+    printVector(deque->toVector());
+    int popFirst = deque->popFirst();
+    cout << "队首出队元素 = " << popFirst << "，队首出队后 deque = ";
+    printVector(deque->toVector());
+
+    /* 获取双向队列的长度 */
+    int size = deque->size();
+    cout << "双向队列长度 size = " << size << endl;
+
+    /* 判断双向队列是否为空 */
+    bool isEmpty = deque->isEmpty();
+    cout << "双向队列是否为空 = " << boolalpha << isEmpty << endl;
+
+    // 释放内存
+    delete deque;
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/linkedlist_queue.cpp b/chapter_stack_and_queue/linkedlist_queue.cpp
new file mode 100644
index 0000000..687f136
--- /dev/null
+++ b/chapter_stack_and_queue/linkedlist_queue.cpp
@@ -0,0 +1,120 @@
+/**
+ * File: linkedlist_queue.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于链表实现的队列 */
+class LinkedListQueue {
+  private:
+    ListNode *front, *rear; // 头节点 front ，尾节点 rear
+    int queSize;
+
+  public:
+    LinkedListQueue() {
+        front = nullptr;
+        rear = nullptr;
+        queSize = 0;
+    }
+
+    ~LinkedListQueue() {
+        // 遍历链表删除节点，释放内存
+        freeMemoryLinkedList(front);
+    }
+
+    /* 获取队列的长度 */
+    int size() {
+        return queSize;
+    }
+
+    /* 判断队列是否为空 */
+    bool isEmpty() {
+        return queSize == 0;
+    }
+
+    /* 入队 */
+    void push(int num) {
+        // 在尾节点后添加 num
+        ListNode *node = new ListNode(num);
+        // 如果队列为空，则令头、尾节点都指向该节点
+        if (front == nullptr) {
+            front = node;
+            rear = node;
+        }
+        // 如果队列不为空，则将该节点添加到尾节点后
+        else {
+            rear->next = node;
+            rear = node;
+        }
+        queSize++;
+    }
+
+    /* 出队 */
+    int pop() {
+        int num = peek();
+        // 删除头节点
+        ListNode *tmp = front;
+        front = front->next;
+        // 释放内存
+        delete tmp;
+        queSize--;
+        return num;
+    }
+
+    /* 访问队首元素 */
+    int peek() {
+        if (size() == 0)
+            throw out_of_range("队列为空");
+        return front->val;
+    }
+
+    /* 将链表转化为 Vector 并返回 */
+    vector<int> toVector() {
+        ListNode *node = front;
+        vector<int> res(size());
+        for (int i = 0; i < res.size(); i++) {
+            res[i] = node->val;
+            node = node->next;
+        }
+        return res;
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化队列 */
+    LinkedListQueue *queue = new LinkedListQueue();
+
+    /* 元素入队 */
+    queue->push(1);
+    queue->push(3);
+    queue->push(2);
+    queue->push(5);
+    queue->push(4);
+    cout << "队列 queue = ";
+    printVector(queue->toVector());
+
+    /* 访问队首元素 */
+    int peek = queue->peek();
+    cout << "队首元素 peek = " << peek << endl;
+
+    /* 元素出队 */
+    peek = queue->pop();
+    cout << "出队元素 pop = " << peek << "，出队后 queue = ";
+    printVector(queue->toVector());
+
+    /* 获取队列的长度 */
+    int size = queue->size();
+    cout << "队列长度 size = " << size << endl;
+
+    /* 判断队列是否为空 */
+    bool empty = queue->isEmpty();
+    cout << "队列是否为空 = " << empty << endl;
+
+    // 释放内存
+    delete queue;
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/linkedlist_stack.cpp b/chapter_stack_and_queue/linkedlist_stack.cpp
new file mode 100644
index 0000000..dbf1f67
--- /dev/null
+++ b/chapter_stack_and_queue/linkedlist_stack.cpp
@@ -0,0 +1,109 @@
+/**
+ * File: linkedlist_stack.cpp
+ * Created Time: 2022-11-28
+ * Author: qualifier1024 (2539244001@qq.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 基于链表实现的栈 */
+class LinkedListStack {
+  private:
+    ListNode *stackTop; // 将头节点作为栈顶
+    int stkSize;        // 栈的长度
+
+  public:
+    LinkedListStack() {
+        stackTop = nullptr;
+        stkSize = 0;
+    }
+
+    ~LinkedListStack() {
+        // 遍历链表删除节点，释放内存
+        freeMemoryLinkedList(stackTop);
+    }
+
+    /* 获取栈的长度 */
+    int size() {
+        return stkSize;
+    }
+
+    /* 判断栈是否为空 */
+    bool isEmpty() {
+        return size() == 0;
+    }
+
+    /* 入栈 */
+    void push(int num) {
+        ListNode *node = new ListNode(num);
+        node->next = stackTop;
+        stackTop = node;
+        stkSize++;
+    }
+
+    /* 出栈 */
+    int pop() {
+        int num = top();
+        ListNode *tmp = stackTop;
+        stackTop = stackTop->next;
+        // 释放内存
+        delete tmp;
+        stkSize--;
+        return num;
+    }
+
+    /* 访问栈顶元素 */
+    int top() {
+        if (isEmpty())
+            throw out_of_range("栈为空");
+        return stackTop->val;
+    }
+
+    /* 将 List 转化为 Array 并返回 */
+    vector<int> toVector() {
+        ListNode *node = stackTop;
+        vector<int> res(size());
+        for (int i = res.size() - 1; i >= 0; i--) {
+            res[i] = node->val;
+            node = node->next;
+        }
+        return res;
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化栈 */
+    LinkedListStack *stack = new LinkedListStack();
+
+    /* 元素入栈 */
+    stack->push(1);
+    stack->push(3);
+    stack->push(2);
+    stack->push(5);
+    stack->push(4);
+    cout << "栈 stack = ";
+    printVector(stack->toVector());
+
+    /* 访问栈顶元素 */
+    int top = stack->top();
+    cout << "栈顶元素 top = " << top << endl;
+
+    /* 元素出栈 */
+    top = stack->pop();
+    cout << "出栈元素 pop = " << top << "，出栈后 stack = ";
+    printVector(stack->toVector());
+
+    /* 获取栈的长度 */
+    int size = stack->size();
+    cout << "栈的长度 size = " << size << endl;
+
+    /* 判断是否为空 */
+    bool empty = stack->isEmpty();
+    cout << "栈是否为空 = " << empty << endl;
+
+    // 释放内存
+    delete stack;
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/queue.cpp b/chapter_stack_and_queue/queue.cpp
new file mode 100644
index 0000000..b94ba40
--- /dev/null
+++ b/chapter_stack_and_queue/queue.cpp
@@ -0,0 +1,41 @@
+/**
+ * File: queue.cpp
+ * Created Time: 2022-11-28
+ * Author: qualifier1024 (2539244001@qq.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化队列 */
+    queue<int> queue;
+
+    /* 元素入队 */
+    queue.push(1);
+    queue.push(3);
+    queue.push(2);
+    queue.push(5);
+    queue.push(4);
+    cout << "队列 queue = ";
+    printQueue(queue);
+
+    /* 访问队首元素 */
+    int front = queue.front();
+    cout << "队首元素 front = " << front << endl;
+
+    /* 元素出队 */
+    queue.pop();
+    cout << "出队元素 front = " << front << "，出队后 queue = ";
+    printQueue(queue);
+
+    /* 获取队列的长度 */
+    int size = queue.size();
+    cout << "队列长度 size = " << size << endl;
+
+    /* 判断队列是否为空 */
+    bool empty = queue.empty();
+    cout << "队列是否为空 = " << empty << endl;
+
+    return 0;
+}
diff --git a/chapter_stack_and_queue/stack.cpp b/chapter_stack_and_queue/stack.cpp
new file mode 100644
index 0000000..18743bf
--- /dev/null
+++ b/chapter_stack_and_queue/stack.cpp
@@ -0,0 +1,41 @@
+/**
+ * File: stack.cpp
+ * Created Time: 2022-11-28
+ * Author: qualifier1024 (2539244001@qq.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化栈 */
+    stack<int> stack;
+
+    /* 元素入栈 */
+    stack.push(1);
+    stack.push(3);
+    stack.push(2);
+    stack.push(5);
+    stack.push(4);
+    cout << "栈 stack = ";
+    printStack(stack);
+
+    /* 访问栈顶元素 */
+    int top = stack.top();
+    cout << "栈顶元素 top = " << top << endl;
+
+    /* 元素出栈 */
+    stack.pop(); // 无返回值
+    cout << "出栈元素 pop = " << top << "，出栈后 stack = ";
+    printStack(stack);
+
+    /* 获取栈的长度 */
+    int size = stack.size();
+    cout << "栈的长度 size = " << size << endl;
+
+    /* 判断是否为空 */
+    bool empty = stack.empty();
+    cout << "栈是否为空 = " << empty << endl;
+
+    return 0;
+}
diff --git a/chapter_tree/CMakeLists.txt b/chapter_tree/CMakeLists.txt
new file mode 100644
index 0000000..fa7009b
--- /dev/null
+++ b/chapter_tree/CMakeLists.txt
@@ -0,0 +1,6 @@
+add_executable(avl_tree avl_tree.cpp)
+add_executable(binary_search_tree binary_search_tree.cpp)
+add_executable(binary_tree binary_tree.cpp)
+add_executable(binary_tree_bfs binary_tree_bfs.cpp)
+add_executable(binary_tree_dfs binary_tree_dfs.cpp)
+add_executable(array_binary_tree array_binary_tree.cpp)
\ No newline at end of file
diff --git a/chapter_tree/array_binary_tree.cpp b/chapter_tree/array_binary_tree.cpp
new file mode 100644
index 0000000..031c664
--- /dev/null
+++ b/chapter_tree/array_binary_tree.cpp
@@ -0,0 +1,137 @@
+/**
+ * File: array_binary_tree.cpp
+ * Created Time: 2023-07-19
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 数组表示下的二叉树类 */
+class ArrayBinaryTree {
+  public:
+    /* 构造方法 */
+    ArrayBinaryTree(vector<int> arr) {
+        tree = arr;
+    }
+
+    /* 列表容量 */
+    int size() {
+        return tree.size();
+    }
+
+    /* 获取索引为 i 节点的值 */
+    int val(int i) {
+        // 若索引越界，则返回 INT_MAX ，代表空位
+        if (i < 0 || i >= size())
+            return INT_MAX;
+        return tree[i];
+    }
+
+    /* 获取索引为 i 节点的左子节点的索引 */
+    int left(int i) {
+        return 2 * i + 1;
+    }
+
+    /* 获取索引为 i 节点的右子节点的索引 */
+    int right(int i) {
+        return 2 * i + 2;
+    }
+
+    /* 获取索引为 i 节点的父节点的索引 */
+    int parent(int i) {
+        return (i - 1) / 2;
+    }
+
+    /* 层序遍历 */
+    vector<int> levelOrder() {
+        vector<int> res;
+        // 直接遍历数组
+        for (int i = 0; i < size(); i++) {
+            if (val(i) != INT_MAX)
+                res.push_back(val(i));
+        }
+        return res;
+    }
+
+    /* 前序遍历 */
+    vector<int> preOrder() {
+        vector<int> res;
+        dfs(0, "pre", res);
+        return res;
+    }
+
+    /* 中序遍历 */
+    vector<int> inOrder() {
+        vector<int> res;
+        dfs(0, "in", res);
+        return res;
+    }
+
+    /* 后序遍历 */
+    vector<int> postOrder() {
+        vector<int> res;
+        dfs(0, "post", res);
+        return res;
+    }
+
+  private:
+    vector<int> tree;
+
+    /* 深度优先遍历 */
+    void dfs(int i, string order, vector<int> &res) {
+        // 若为空位，则返回
+        if (val(i) == INT_MAX)
+            return;
+        // 前序遍历
+        if (order == "pre")
+            res.push_back(val(i));
+        dfs(left(i), order, res);
+        // 中序遍历
+        if (order == "in")
+            res.push_back(val(i));
+        dfs(right(i), order, res);
+        // 后序遍历
+        if (order == "post")
+            res.push_back(val(i));
+    }
+};
+
+/* Driver Code */
+int main() {
+    // 初始化二叉树
+    // 使用 INT_MAX 代表空位 nullptr
+    vector<int> arr = {1, 2, 3, 4, INT_MAX, 6, 7, 8, 9, INT_MAX, INT_MAX, 12, INT_MAX, INT_MAX, 15};
+    TreeNode *root = vectorToTree(arr);
+    cout << "\n初始化二叉树\n";
+    cout << "二叉树的数组表示：\n";
+    printVector(arr);
+    cout << "二叉树的链表表示：\n";
+    printTree(root);
+
+    // 数组表示下的二叉树类
+    ArrayBinaryTree abt(arr);
+
+    // 访问节点
+    int i = 1;
+    int l = abt.left(i), r = abt.right(i), p = abt.parent(i);
+    cout << "\n当前节点的索引为 " << i << "，值为 " << abt.val(i) << "\n";
+    cout << "其左子节点的索引为 " << l << "，值为 " << (l != INT_MAX ? to_string(abt.val(l)) : "nullptr") << "\n";
+    cout << "其右子节点的索引为 " << r << "，值为 " << (r != INT_MAX ? to_string(abt.val(r)) : "nullptr") << "\n";
+    cout << "其父节点的索引为 " << p << "，值为 " << (p != INT_MAX ? to_string(abt.val(p)) : "nullptr") << "\n";
+
+    // 遍历树
+    vector<int> res = abt.levelOrder();
+    cout << "\n层序遍历为： ";
+    printVector(res);
+    res = abt.preOrder();
+    cout << "前序遍历为： ";
+    printVector(res);
+    res = abt.inOrder();
+    cout << "中序遍历为： ";
+    printVector(res);
+    res = abt.postOrder();
+    cout << "后序遍历为： ";
+    printVector(res);
+
+    return 0;
+}
diff --git a/chapter_tree/avl_tree.cpp b/chapter_tree/avl_tree.cpp
new file mode 100644
index 0000000..be5b40d
--- /dev/null
+++ b/chapter_tree/avl_tree.cpp
@@ -0,0 +1,233 @@
+/**
+ * File: avl_tree.cpp
+ * Created Time: 2023-02-03
+ * Author: what-is-me (whatisme@outlook.jp)
+ */
+
+#include "../utils/common.hpp"
+
+/* AVL 树 */
+class AVLTree {
+  public:
+    TreeNode *root; // 根节点
+  private:
+    /* 更新节点高度 */
+    void updateHeight(TreeNode *node) {
+        // 节点高度等于最高子树高度 + 1
+        node->height = max(height(node->left), height(node->right)) + 1;
+    }
+
+    /* 右旋操作 */
+    TreeNode *rightRotate(TreeNode *node) {
+        TreeNode *child = node->left;
+        TreeNode *grandChild = child->right;
+        // 以 child 为原点，将 node 向右旋转
+        child->right = node;
+        node->left = grandChild;
+        // 更新节点高度
+        updateHeight(node);
+        updateHeight(child);
+        // 返回旋转后子树的根节点
+        return child;
+    }
+
+    /* 左旋操作 */
+    TreeNode *leftRotate(TreeNode *node) {
+        TreeNode *child = node->right;
+        TreeNode *grandChild = child->left;
+        // 以 child 为原点，将 node 向左旋转
+        child->left = node;
+        node->right = grandChild;
+        // 更新节点高度
+        updateHeight(node);
+        updateHeight(child);
+        // 返回旋转后子树的根节点
+        return child;
+    }
+
+    /* 执行旋转操作，使该子树重新恢复平衡 */
+    TreeNode *rotate(TreeNode *node) {
+        // 获取节点 node 的平衡因子
+        int _balanceFactor = balanceFactor(node);
+        // 左偏树
+        if (_balanceFactor > 1) {
+            if (balanceFactor(node->left) >= 0) {
+                // 右旋
+                return rightRotate(node);
+            } else {
+                // 先左旋后右旋
+                node->left = leftRotate(node->left);
+                return rightRotate(node);
+            }
+        }
+        // 右偏树
+        if (_balanceFactor < -1) {
+            if (balanceFactor(node->right) <= 0) {
+                // 左旋
+                return leftRotate(node);
+            } else {
+                // 先右旋后左旋
+                node->right = rightRotate(node->right);
+                return leftRotate(node);
+            }
+        }
+        // 平衡树，无须旋转，直接返回
+        return node;
+    }
+
+    /* 递归插入节点（辅助方法） */
+    TreeNode *insertHelper(TreeNode *node, int val) {
+        if (node == nullptr)
+            return new TreeNode(val);
+        /* 1. 查找插入位置并插入节点 */
+        if (val < node->val)
+            node->left = insertHelper(node->left, val);
+        else if (val > node->val)
+            node->right = insertHelper(node->right, val);
+        else
+            return node;    // 重复节点不插入，直接返回
+        updateHeight(node); // 更新节点高度
+        /* 2. 执行旋转操作，使该子树重新恢复平衡 */
+        node = rotate(node);
+        // 返回子树的根节点
+        return node;
+    }
+
+    /* 递归删除节点（辅助方法） */
+    TreeNode *removeHelper(TreeNode *node, int val) {
+        if (node == nullptr)
+            return nullptr;
+        /* 1. 查找节点并删除 */
+        if (val < node->val)
+            node->left = removeHelper(node->left, val);
+        else if (val > node->val)
+            node->right = removeHelper(node->right, val);
+        else {
+            if (node->left == nullptr || node->right == nullptr) {
+                TreeNode *child = node->left != nullptr ? node->left : node->right;
+                // 子节点数量 = 0 ，直接删除 node 并返回
+                if (child == nullptr) {
+                    delete node;
+                    return nullptr;
+                }
+                // 子节点数量 = 1 ，直接删除 node
+                else {
+                    delete node;
+                    node = child;
+                }
+            } else {
+                // 子节点数量 = 2 ，则将中序遍历的下个节点删除，并用该节点替换当前节点
+                TreeNode *temp = node->right;
+                while (temp->left != nullptr) {
+                    temp = temp->left;
+                }
+                int tempVal = temp->val;
+                node->right = removeHelper(node->right, temp->val);
+                node->val = tempVal;
+            }
+        }
+        updateHeight(node); // 更新节点高度
+        /* 2. 执行旋转操作，使该子树重新恢复平衡 */
+        node = rotate(node);
+        // 返回子树的根节点
+        return node;
+    }
+
+  public:
+    /* 获取节点高度 */
+    int height(TreeNode *node) {
+        // 空节点高度为 -1 ，叶节点高度为 0
+        return node == nullptr ? -1 : node->height;
+    }
+
+    /* 获取平衡因子 */
+    int balanceFactor(TreeNode *node) {
+        // 空节点平衡因子为 0
+        if (node == nullptr)
+            return 0;
+        // 节点平衡因子 = 左子树高度 - 右子树高度
+        return height(node->left) - height(node->right);
+    }
+
+    /* 插入节点 */
+    void insert(int val) {
+        root = insertHelper(root, val);
+    }
+
+    /* 删除节点 */
+    void remove(int val) {
+        root = removeHelper(root, val);
+    }
+
+    /* 查找节点 */
+    TreeNode *search(int val) {
+        TreeNode *cur = root;
+        // 循环查找，越过叶节点后跳出
+        while (cur != nullptr) {
+            // 目标节点在 cur 的右子树中
+            if (cur->val < val)
+                cur = cur->right;
+            // 目标节点在 cur 的左子树中
+            else if (cur->val > val)
+                cur = cur->left;
+            // 找到目标节点，跳出循环
+            else
+                break;
+        }
+        // 返回目标节点
+        return cur;
+    }
+
+    /*构造方法*/
+    AVLTree() : root(nullptr) {
+    }
+
+    /*析构方法*/
+    ~AVLTree() {
+        freeMemoryTree(root);
+    }
+};
+
+void testInsert(AVLTree &tree, int val) {
+    tree.insert(val);
+    cout << "\n插入节点 " << val << " 后，AVL 树为" << endl;
+    printTree(tree.root);
+}
+
+void testRemove(AVLTree &tree, int val) {
+    tree.remove(val);
+    cout << "\n删除节点 " << val << " 后，AVL 树为" << endl;
+    printTree(tree.root);
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化空 AVL 树 */
+    AVLTree avlTree;
+
+    /* 插入节点 */
+    // 请关注插入节点后，AVL 树是如何保持平衡的
+    testInsert(avlTree, 1);
+    testInsert(avlTree, 2);
+    testInsert(avlTree, 3);
+    testInsert(avlTree, 4);
+    testInsert(avlTree, 5);
+    testInsert(avlTree, 8);
+    testInsert(avlTree, 7);
+    testInsert(avlTree, 9);
+    testInsert(avlTree, 10);
+    testInsert(avlTree, 6);
+
+    /* 插入重复节点 */
+    testInsert(avlTree, 7);
+
+    /* 删除节点 */
+    // 请关注删除节点后，AVL 树是如何保持平衡的
+    testRemove(avlTree, 8); // 删除度为 0 的节点
+    testRemove(avlTree, 5); // 删除度为 1 的节点
+    testRemove(avlTree, 4); // 删除度为 2 的节点
+
+    /* 查询节点 */
+    TreeNode *node = avlTree.search(7);
+    cout << "\n查找到的节点对象为 " << node << "，节点值 = " << node->val << endl;
+}
diff --git a/chapter_tree/binary_search_tree.cpp b/chapter_tree/binary_search_tree.cpp
new file mode 100644
index 0000000..420d0d1
--- /dev/null
+++ b/chapter_tree/binary_search_tree.cpp
@@ -0,0 +1,170 @@
+/**
+ * File: binary_search_tree.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 二叉搜索树 */
+class BinarySearchTree {
+  private:
+    TreeNode *root;
+
+  public:
+    /* 构造方法 */
+    BinarySearchTree() {
+        // 初始化空树
+        root = nullptr;
+    }
+
+    /* 析构方法 */
+    ~BinarySearchTree() {
+        freeMemoryTree(root);
+    }
+
+    /* 获取二叉树根节点 */
+    TreeNode *getRoot() {
+        return root;
+    }
+
+    /* 查找节点 */
+    TreeNode *search(int num) {
+        TreeNode *cur = root;
+        // 循环查找，越过叶节点后跳出
+        while (cur != nullptr) {
+            // 目标节点在 cur 的右子树中
+            if (cur->val < num)
+                cur = cur->right;
+            // 目标节点在 cur 的左子树中
+            else if (cur->val > num)
+                cur = cur->left;
+            // 找到目标节点，跳出循环
+            else
+                break;
+        }
+        // 返回目标节点
+        return cur;
+    }
+
+    /* 插入节点 */
+    void insert(int num) {
+        // 若树为空，则初始化根节点
+        if (root == nullptr) {
+            root = new TreeNode(num);
+            return;
+        }
+        TreeNode *cur = root, *pre = nullptr;
+        // 循环查找，越过叶节点后跳出
+        while (cur != nullptr) {
+            // 找到重复节点，直接返回
+            if (cur->val == num)
+                return;
+            pre = cur;
+            // 插入位置在 cur 的右子树中
+            if (cur->val < num)
+                cur = cur->right;
+            // 插入位置在 cur 的左子树中
+            else
+                cur = cur->left;
+        }
+        // 插入节点
+        TreeNode *node = new TreeNode(num);
+        if (pre->val < num)
+            pre->right = node;
+        else
+            pre->left = node;
+    }
+
+    /* 删除节点 */
+    void remove(int num) {
+        // 若树为空，直接提前返回
+        if (root == nullptr)
+            return;
+        TreeNode *cur = root, *pre = nullptr;
+        // 循环查找，越过叶节点后跳出
+        while (cur != nullptr) {
+            // 找到待删除节点，跳出循环
+            if (cur->val == num)
+                break;
+            pre = cur;
+            // 待删除节点在 cur 的右子树中
+            if (cur->val < num)
+                cur = cur->right;
+            // 待删除节点在 cur 的左子树中
+            else
+                cur = cur->left;
+        }
+        // 若无待删除节点，则直接返回
+        if (cur == nullptr)
+            return;
+        // 子节点数量 = 0 or 1
+        if (cur->left == nullptr || cur->right == nullptr) {
+            // 当子节点数量 = 0 / 1 时， child = nullptr / 该子节点
+            TreeNode *child = cur->left != nullptr ? cur->left : cur->right;
+            // 删除节点 cur
+            if (cur != root) {
+                if (pre->left == cur)
+                    pre->left = child;
+                else
+                    pre->right = child;
+            } else {
+                // 若删除节点为根节点，则重新指定根节点
+                root = child;
+            }
+            // 释放内存
+            delete cur;
+        }
+        // 子节点数量 = 2
+        else {
+            // 获取中序遍历中 cur 的下一个节点
+            TreeNode *tmp = cur->right;
+            while (tmp->left != nullptr) {
+                tmp = tmp->left;
+            }
+            int tmpVal = tmp->val;
+            // 递归删除节点 tmp
+            remove(tmp->val);
+            // 用 tmp 覆盖 cur
+            cur->val = tmpVal;
+        }
+    }
+};
+
+/* Driver Code */
+int main() {
+    /* 初始化二叉搜索树 */
+    BinarySearchTree *bst = new BinarySearchTree();
+    // 请注意，不同的插入顺序会生成不同的二叉树，该序列可以生成一个完美二叉树
+    vector<int> nums = {8, 4, 12, 2, 6, 10, 14, 1, 3, 5, 7, 9, 11, 13, 15};
+    for (int num : nums) {
+        bst->insert(num);
+    }
+    cout << endl << "初始化的二叉树为\n" << endl;
+    printTree(bst->getRoot());
+
+    /* 查找节点 */
+    TreeNode *node = bst->search(7);
+    cout << endl << "查找到的节点对象为 " << node << "，节点值 = " << node->val << endl;
+
+    /* 插入节点 */
+    bst->insert(16);
+    cout << endl << "插入节点 16 后，二叉树为\n" << endl;
+    printTree(bst->getRoot());
+
+    /* 删除节点 */
+    bst->remove(1);
+    cout << endl << "删除节点 1 后，二叉树为\n" << endl;
+    printTree(bst->getRoot());
+    bst->remove(2);
+    cout << endl << "删除节点 2 后，二叉树为\n" << endl;
+    printTree(bst->getRoot());
+    bst->remove(4);
+    cout << endl << "删除节点 4 后，二叉树为\n" << endl;
+    printTree(bst->getRoot());
+
+    // 释放内存
+    delete bst;
+
+    return 0;
+}
diff --git a/chapter_tree/binary_tree.cpp b/chapter_tree/binary_tree.cpp
new file mode 100644
index 0000000..8146d6a
--- /dev/null
+++ b/chapter_tree/binary_tree.cpp
@@ -0,0 +1,43 @@
+/**
+ * File: binary_tree.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* Driver Code */
+int main() {
+    /* 初始化二叉树 */
+    // 初始化节点
+    TreeNode *n1 = new TreeNode(1);
+    TreeNode *n2 = new TreeNode(2);
+    TreeNode *n3 = new TreeNode(3);
+    TreeNode *n4 = new TreeNode(4);
+    TreeNode *n5 = new TreeNode(5);
+    // 构建节点之间的引用（指针）
+    n1->left = n2;
+    n1->right = n3;
+    n2->left = n4;
+    n2->right = n5;
+    cout << endl << "初始化二叉树\n" << endl;
+    printTree(n1);
+
+    /* 插入与删除节点 */
+    TreeNode *P = new TreeNode(0);
+    // 在 n1 -> n2 中间插入节点 P
+    n1->left = P;
+    P->left = n2;
+    cout << endl << "插入节点 P 后\n" << endl;
+    printTree(n1);
+    // 删除节点 P
+    n1->left = n2;
+    delete P; // 释放内存
+    cout << endl << "删除节点 P 后\n" << endl;
+    printTree(n1);
+
+    // 释放内存
+    freeMemoryTree(n1);
+
+    return 0;
+}
diff --git a/chapter_tree/binary_tree_bfs.cpp b/chapter_tree/binary_tree_bfs.cpp
new file mode 100644
index 0000000..587514b
--- /dev/null
+++ b/chapter_tree/binary_tree_bfs.cpp
@@ -0,0 +1,42 @@
+/**
+ * File: binary_tree_bfs.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+/* 层序遍历 */
+vector<int> levelOrder(TreeNode *root) {
+    // 初始化队列，加入根节点
+    queue<TreeNode *> queue;
+    queue.push(root);
+    // 初始化一个列表，用于保存遍历序列
+    vector<int> vec;
+    while (!queue.empty()) {
+        TreeNode *node = queue.front();
+        queue.pop();              // 队列出队
+        vec.push_back(node->val); // 保存节点值
+        if (node->left != nullptr)
+            queue.push(node->left); // 左子节点入队
+        if (node->right != nullptr)
+            queue.push(node->right); // 右子节点入队
+    }
+    return vec;
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化二叉树 */
+    // 这里借助了一个从数组直接生成二叉树的函数
+    TreeNode *root = vectorToTree(vector<int>{1, 2, 3, 4, 5, 6, 7});
+    cout << endl << "初始化二叉树\n" << endl;
+    printTree(root);
+
+    /* 层序遍历 */
+    vector<int> vec = levelOrder(root);
+    cout << endl << "层序遍历的节点打印序列 = ";
+    printVector(vec);
+
+    return 0;
+}
diff --git a/chapter_tree/binary_tree_dfs.cpp b/chapter_tree/binary_tree_dfs.cpp
new file mode 100644
index 0000000..778c2a0
--- /dev/null
+++ b/chapter_tree/binary_tree_dfs.cpp
@@ -0,0 +1,69 @@
+/**
+ * File: binary_tree_dfs.cpp
+ * Created Time: 2022-11-25
+ * Author: krahets (krahets@163.com)
+ */
+
+#include "../utils/common.hpp"
+
+// 初始化列表，用于存储遍历序列
+vector<int> vec;
+
+/* 前序遍历 */
+void preOrder(TreeNode *root) {
+    if (root == nullptr)
+        return;
+    // 访问优先级：根节点 -> 左子树 -> 右子树
+    vec.push_back(root->val);
+    preOrder(root->left);
+    preOrder(root->right);
+}
+
+/* 中序遍历 */
+void inOrder(TreeNode *root) {
+    if (root == nullptr)
+        return;
+    // 访问优先级：左子树 -> 根节点 -> 右子树
+    inOrder(root->left);
+    vec.push_back(root->val);
+    inOrder(root->right);
+}
+
+/* 后序遍历 */
+void postOrder(TreeNode *root) {
+    if (root == nullptr)
+        return;
+    // 访问优先级：左子树 -> 右子树 -> 根节点
+    postOrder(root->left);
+    postOrder(root->right);
+    vec.push_back(root->val);
+}
+
+/* Driver Code */
+int main() {
+    /* 初始化二叉树 */
+    // 这里借助了一个从数组直接生成二叉树的函数
+    TreeNode *root = vectorToTree(vector<int>{1, 2, 3, 4, 5, 6, 7});
+    cout << endl << "初始化二叉树\n" << endl;
+    printTree(root);
+
+    /* 前序遍历 */
+    vec.clear();
+    preOrder(root);
+    cout << endl << "前序遍历的节点打印序列 = ";
+    printVector(vec);
+
+    /* 中序遍历 */
+    vec.clear();
+    inOrder(root);
+    cout << endl << "中序遍历的节点打印序列 = ";
+    printVector(vec);
+
+    /* 后序遍历 */
+    vec.clear();
+    postOrder(root);
+    cout << endl << "后序遍历的节点打印序列 = ";
+    printVector(vec);
+
+    return 0;
+}
diff --git a/test/output/priority_queue_demo.exe b/test/output/priority_queue_demo.exe
new file mode 100644
index 0000000..6e9c2df
Binary files /dev/null and b/test/output/priority_queue_demo.exe differ
diff --git a/test/priority_queue_demo.cpp b/test/priority_queue_demo.cpp
new file mode 100644
index 0000000..cf7ebe6
--- /dev/null
+++ b/test/priority_queue_demo.cpp
@@ -0,0 +1,28 @@
+#include <queue>
+#include <iostream>
+
+struct Person {
+    std::string name;
+    int age;
+};
+
+struct CompareByAge {
+    bool operator()(const Person& p1, const Person& p2) const {
+        return p1.age < p2.age;
+    }
+};
+
+int main() {
+    std::priority_queue<Person, std::vector<Person>, CompareByAge> pq;
+
+    pq.push({"Alice", 25});
+    pq.push({"Bob", 30});
+    pq.push({"Charlie", 20});
+
+    while (!pq.empty()) {
+        std::cout << pq.top().name << " ";
+        pq.pop();
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/utils/CMakeLists.txt b/utils/CMakeLists.txt
new file mode 100644
index 0000000..775a558
--- /dev/null
+++ b/utils/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_executable(utils
+        common.hpp print_utils.hpp
+        list_node.hpp tree_node.hpp
+        vertex.hpp)
\ No newline at end of file
diff --git a/utils/common.hpp b/utils/common.hpp
new file mode 100644
index 0000000..c72dabd
--- /dev/null
+++ b/utils/common.hpp
@@ -0,0 +1,28 @@
+/**
+ * File: common.hpp
+ * Created Time: 2021-12-19
+ * Author: krahets (krahets@163.com)
+ */
+
+#pragma once
+
+#include <algorithm>
+#include <chrono>
+#include <deque>
+#include <iostream>
+#include <list>
+#include <queue>
+#include <random>
+#include <set>
+#include <stack>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include "list_node.hpp"
+#include "print_utils.hpp"
+#include "tree_node.hpp"
+#include "vertex.hpp"
+
+using namespace std;
diff --git a/utils/list_node.hpp b/utils/list_node.hpp
new file mode 100644
index 0000000..b68d49c
--- /dev/null
+++ b/utils/list_node.hpp
@@ -0,0 +1,59 @@
+/**
+ * File: list_node.hpp
+ * Created Time: 2021-12-19
+ * Author: krahets (krahets@163.com)
+ */
+
+#pragma once
+
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+/* Definition for a singly-linked list node */
+struct ListNode
+{
+    int val;        // �����ǽڵ��ֵ
+    ListNode *next; // ������ָ����һ���ڵ��ָ��
+    ListNode(int x) : val(x), next(nullptr)
+    { // ���캯��: ��ʼ���ڵ��ֵΪx, ָ����һ���ڵ��ָ��Ϊ��
+    }
+};
+
+/* Generate a linked list with a vector */ // ��һ��vector����һ������
+ListNode *vecToLinkedList(vector<int> list)
+{
+    ListNode *dum = new ListNode(0); // ����һ������ڵ� dum (ֵΪ0)
+    ListNode *head = dum;            // ����һ��ָ������ڵ��ָ�� head
+    for (int val : list)
+    {
+        head->next = new ListNode(val); // ����һ���½ڵ�, ֵΪval, ������ָ�븳��head->next
+        head = head->next;              // headָ����һ���ڵ�
+    }
+    return dum->next; // ����������ͷ�ڵ�
+}
+
+/* Get a list node with specific value from a linked list */
+ListNode *getListNode(ListNode *head, int val)
+{
+    // ��������, �ҵ�ֵΪval�Ľڵ�
+    while (head != nullptr && head->val != val)
+    {
+        head = head->next; // ָ����һ���ڵ�
+    }
+    return head; // �����ҵ��Ľڵ�, ���û���ҵ�, ����nullptr
+}
+
+/* Free the memory allocated to a linked list */
+void freeMemoryLinkedList(ListNode *cur)
+{
+    // �ͷ��ڴ�
+    ListNode *pre;
+    while (cur != nullptr) // ��ǰ�ڵ㲻Ϊ��
+    {
+        pre = cur;       // preָ��ǰ�ڵ�
+        cur = cur->next; // ��ǰ�ڵ�ָ����һ���ڵ�
+        delete pre;      // �ͷ�preָ��Ľڵ�
+    }
+}
diff --git a/utils/print_utils.hpp b/utils/print_utils.hpp
new file mode 100644
index 0000000..6686644
--- /dev/null
+++ b/utils/print_utils.hpp
@@ -0,0 +1,289 @@
+/**
+ * File: print_utils.hpp
+ * Created Time: 2021-12-19
+ * Author: krahets (krahets@163.com), msk397 (machangxinq@gmail.com), LoneRanger(836253168@qq.com)
+ */
+
+#pragma once
+
+#include "list_node.hpp"
+#include "tree_node.hpp"
+#include <climits>
+#include <iostream>
+#include <sstream>
+#include <string>
+
+/* Find an element in a vector */ // ��һ�� vector �в���Ԫ��
+template <typename T>
+int vecFind(const vector<T> &vec, T ele)
+{
+    int j = INT_MAX;
+    for (int i = 0; i < vec.size(); i++)
+    {
+        if (vec[i] == ele) // ���ҵ�Ԫ��ʱ������Ԫ�ص��±�
+        {
+            j = i;
+        }
+    }
+    return j;
+}
+
+/* Concatenate a vector with a delim */ // ��һ�� vector ��ָ���ķָ������ӳ��ַ���
+template <typename T>
+string strJoin(const string &delim, const T &vec) // delim �Ƿָ�����vec �� vector(ʹ��&vec��ʾ���ݵ�������, �����ǿ���, �����Ч��)
+{
+    ostringstream s; // ����һ�����������
+    for (const auto &i : vec)
+    {
+        if (&i != &vec[0])
+        {
+            s << delim; // ���ָ������ӵ������������
+        }
+        s << i; // ��Ԫ�����ӵ������������
+    }
+    return s.str(); // .str() ���������������ij�Ա���������ڷ��������������ַ�����ʾ
+}
+
+/* Repeat a string for n times */ // ��һ���ַ����ظ� n ��
+string strRepeat(string str, int n)
+{
+    ostringstream os; // ����һ�����������
+    for (int i = 0; i < n; i++)
+        os << str;   // ���ַ����ظ� n ��
+    return os.str(); // ���������������ַ�����ʾ
+}
+
+/* Print an Array */ // ��ӡһ������
+template <typename T>
+void printArray(T *arr, int n) // arr ��������׵�ַ��n ������ij���
+{
+    cout << "[";
+    for (int i = 0; i < n - 1; i++)
+    {
+        cout << arr[i] << ", "; // �����ӡ����Ԫ��
+    }
+    if (n >= 1)                            // �����鳤�ȴ��ڵ��� 1 ʱ
+        cout << arr[n - 1] << "]" << endl; // ��ӡ�������һ��Ԫ�� �� ����һ�� ']' ����
+    else
+        cout << "]" << endl; // �����鳤��Ϊ 0 ʱ��ֱ�Ӵ�ӡһ�� ']' ����
+}
+
+/* Get the Vector String object */ // ��ȡһ�� vector ���ַ�����ʾ
+template <typename T>
+string getVectorString(vector<T> &list) // list �� vector
+{
+    return "[" + strJoin(", ", list) + "]"; // ʹ�� strJoin ������ vector �ö������ӳ��ַ����������ַ����������� '[' �� ']'
+}
+
+/* Print a vector */ // ��ӡһ�� vector
+template <typename T>
+void printVector(vector<T> list)
+{
+    cout << getVectorString(list) << '\n'; // ʹ�� getVectorString ������ȡ vector ���ַ�����ʾ������ӡ
+}
+
+/* Print a vector matrix */ // ��ӡһ�� vector ����
+template <typename T>
+void printVectorMatrix(vector<vector<T>> &matrix) // matrix ��һ����ά vector, ����ÿ��Ԫ�ض���һ�� vector, ���ڱ�ʾ���� (���������)
+{
+    cout << "[" << '\n';
+    for (vector<T> &list : matrix)                          // ���� matrix �е�ÿһ�� vector Ԫ��
+        cout << "  " + getVectorString(list) + "," << '\n'; // ʹ�� getVectorString ������ȡ vector ���ַ�����ʾ������ӡ
+    cout << "]" << '\n';
+}
+
+/* Print a linked list */ // ��ӡһ������
+void printLinkedList(ListNode *head)
+{
+    vector<int> list;       // ����һ�� vector ���ڴ洢������Ԫ��
+    while (head != nullptr) // ��������: ��������ָ�벻Ϊ��ʱ, ��������
+    {
+        list.push_back(head->val); // ��������Ԫ�����ӵ� vector ��
+        head = head->next;         // ��ָ��ָ����������һ��Ԫ��
+    }
+
+    cout << strJoin(" -> ", list) << '\n'; // ʹ�� strJoin ������ vector �ü�ͷ���ӳ��ַ���������ӡ
+}
+
+/**
+ * This tree printer is borrowed from TECHIE DELIGHT    // ������ӡ���Ǵ� TECHIE DELIGHT ���õ�
+ * https://www.techiedelight.com/c-program-print-binary-tree/
+ */
+struct Trunk // ���ɽṹ��
+{
+    Trunk *prev;                   // ָ����һ������
+    string str;                    // ���ɵ��ַ�����ʾ
+    Trunk(Trunk *prev, string str) // ���캯�� ��cpp �е� struct Ҳ�����й��캯����
+    {
+        this->prev = prev;
+        this->str = str;
+    }
+};
+
+/* Helper function to print branches of the binary tree */ // ���ڴ�ӡ�������ĸ�������
+void showTrunks(Trunk *p)
+{
+    if (p == nullptr) // ������Ϊ��ʱ��ֱ�ӷ���
+    {
+        return;
+    }
+
+    // �ݹ���õ�˳�����ӡ��˳���෴
+    showTrunks(p->prev); // �ݹ���� showTrunks ����
+    cout << p->str;      // ��ӡ���ɵ��ַ�����ʾ
+}
+
+/* Print a binary tree */ // ��ӡһ��������
+void printTree(TreeNode *root, Trunk *prev, bool isRight)
+{
+    if (root == nullptr)
+    {
+        return;
+    }
+
+    string prev_str = "    ";    // ��ʼ�� prev_str Ϊ�ո�
+    Trunk trunk(prev, prev_str); // ����һ�����ɶ���
+
+    printTree(root->right, &trunk, true); // �ݹ���� printTree ��������ӡ������
+
+    if (!prev) // ������Ϊ��ʱ
+    {
+        trunk.str = "������"; // ���ɵ��ַ�����ʾΪ "������"
+    }
+    else if (isRight) // �����ɲ�Ϊ������������ʱ
+    {
+        trunk.str = "/������"; // ���ɵ��ַ�����ʾΪ "/������"
+        prev_str = "   |";  // prev_str Ϊ "   |"
+    }
+    else // �����ɲ�Ϊ���Ҳ���������ʱ
+    {
+        trunk.str = "\\������";  // ���ɵ��ַ�����ʾΪ "\������"
+        prev->str = prev_str; // prev_str Ϊ prev->str
+    }
+
+    showTrunks(&trunk);               // ���� showTrunks ��������ӡ����
+    cout << " " << root->val << endl; // ��ӡ�ڵ��ֵ
+
+    if (prev) // �����ɲ�Ϊ��ʱ
+    {
+        prev->str = prev_str; // prev->str Ϊ prev_str
+    }
+    trunk.str = "   |"; // ���ɵ��ַ�����ʾΪ "   |"
+
+    printTree(root->left, &trunk, false); // �ݹ���� printTree ��������ӡ������
+}
+
+/* The interface of the tree printer */ // ��������ӡ���Ľӿ� (��������: Ŀ����Ϊ�˷������)
+void printTree(TreeNode *root)
+{
+    printTree(root, nullptr, false); // ���� printTree ���� (���ذ汾)
+}
+
+/* Print a stack */ // ��ӡһ��ջ
+template <typename T>
+void printStack(stack<T> stk)
+{
+    // Reverse the input stack  // ��ת�����ջ
+    stack<T> tmp;        // ����һ����ʱջ
+    while (!stk.empty()) // �������ջ��Ϊ��ʱ (���������ջ)
+    {
+        tmp.push(stk.top()); // �������ջ��Ԫ��������ӵ���ʱջ��
+        stk.pop();           // ���������ջ��Ԫ��
+    }
+
+    // Generate the string to print // ����Ҫ��ӡ���ַ���
+    ostringstream s;  // ����һ�����������
+    bool flag = true; // ����һ����־λ (Ĭ��Ϊ true), ��������Ƿ��ǵ�һ��Ԫ��
+    while (!tmp.empty())
+    {
+        if (flag)
+        {
+            s << tmp.top(); // ����־λΪ true ʱ����ջ��Ԫ�����ӵ������������
+            flag = false;   // ����־λ����Ϊ false
+        }
+        else                        // ����־λΪ false ʱ
+            s << ", " << tmp.top(); // ��ջ��Ԫ�����ӵ������������
+        tmp.pop();                  // ����ջ��Ԫ��
+    }
+    cout << "[" + s.str() + "]" << '\n'; // ʹ�������������ַ�����ʾ������ӡ
+}
+
+/* Print a queue */ // ��ӡһ������
+template <typename T>
+void printQueue(queue<T> queue) // queue �Ƕ���
+{
+    // Generate the string to print // ����Ҫ��ӡ���ַ���
+    ostringstream s;
+    bool flag = true;
+    while (!queue.empty())
+    {
+        if (flag)
+        {
+            s << queue.front(); // ����־λΪ true ʱ�������еĶ���Ԫ�����ӵ������������ (true ��ʾ�ǵ�һ��Ԫ��)
+            flag = false;
+        }
+        else
+            s << ", " << queue.front(); // ����־λΪ false ʱ�������еĶ���Ԫ��ǰ������һ�����ţ������ӵ������������
+        queue.pop();                    // ��������Ԫ��
+    }
+    cout << "[" + s.str() + "]" << '\n'; // ʹ�������������ַ�����ʾ������ӡ
+}
+
+/* Print a deque */ // ��ӡһ��˫�˶���
+template <typename T>
+void printDeque(deque<T> deque) // deque ��˫�˶���(���� deck)
+{
+    // Generate the string to print // ����Ҫ��ӡ���ַ���
+    ostringstream s;
+    bool flag = true;
+    while (!deque.empty()) // ��˫�˶��в�Ϊ��ʱ
+    {
+        if (flag)
+        {
+            s << deque.front();
+            flag = false;
+        }
+        else
+            s << ", " << deque.front();
+        deque.pop_front(); // ��������Ԫ��
+    }
+    cout << "[" + s.str() + "]" << '\n';
+}
+
+/* Print a HashMap */ // ��ӡһ����ϣ��
+// ����ģ����� TKey �� TValue ������ָ����ֵ�Ե�����
+template <typename TKey, typename TValue>
+void printHashMap(unordered_map<TKey, TValue> map) // map �ǹ�ϣ��
+{
+    for (auto kv : map) // auto �ؼ��������Զ��Ƶ�����������
+    {
+        cout << kv.first << " -> " << kv.second << '\n'; // .first ��ʾ����.second ��ʾֵ
+    }
+}
+
+/* Expose the underlying storage of the priority_queue container */ // ��¶���ȶ��������ĵײ�洢
+template <typename T, typename S, typename C>
+S &Container(priority_queue<T, S, C> &pq) // pq �����ȶ���
+{
+    struct HackedQueue : private priority_queue<T, S, C> // ����һ��˽�м̳е����ȶ���
+    {
+        static S &Container(priority_queue<T, S, C> &pq) // ����һ����̬��Ա���� Container
+        {
+            return pq.*&HackedQueue::c; // �������ȶ��еĵײ�洢
+        }
+    };
+    return HackedQueue::Container(pq); // ���þ�̬��Ա���� Container
+}
+
+/* Print a Heap (PriorityQueue) */ // ��ӡһ���ѣ����ȶ��У�
+template <typename T, typename S, typename C>
+void printHeap(priority_queue<T, S, C> &heap) // heap �����ȶ���
+{
+    vector<T> vec = Container(heap); // ��ȡ���ȶ��еĵײ�洢
+    cout << "�ѵ������ʾ��";
+    printVector(vec);
+    cout << "�ѵ���״��ʾ��" << endl;
+    TreeNode *root = vectorToTree(vec); // �½�һ�������� root�������ȶ��еĵײ�洢ת��Ϊ������
+    printTree(root);
+    freeMemoryTree(root);
+}
diff --git a/utils/tree_node.hpp b/utils/tree_node.hpp
new file mode 100644
index 0000000..de54044
--- /dev/null
+++ b/utils/tree_node.hpp
@@ -0,0 +1,120 @@
+/**
+ * File: tree_node.hpp
+ * Created Time: 2021-12-19
+ * Author: krahets (krahets@163.com)
+ */
+
+#pragma once
+
+#include <limits.h>
+#include <vector>
+
+using namespace std;
+
+/* �������ڵ�ṹ�� */
+struct TreeNode
+{
+    int val{};            // �ڵ��ֵ val {} ��ʾ��ʼ��Ϊ 0 �� nullptr ({} �� C++11 ��������: ֵ��ʼ��)
+    int height = 0;       // �ڵ�ĸ߶�
+    TreeNode *parent{};   // ���ڵ� {} ��ʾ��ʼ��Ϊ nullptr
+    TreeNode *left{};     // ���� {} ��ʾ��ʼ��Ϊ nullptr
+    TreeNode *right{};    // �Һ��� {} ��ʾ��ʼ��Ϊ nullptr
+    TreeNode() = default; // Ĭ�Ϲ��캯��
+    explicit TreeNode(int x, TreeNode *parent = nullptr) : val(x), parent(parent)
+    {
+    } // ���캯��: ��ʼ���ڵ��ֵΪx, ���ڵ�Ϊparent
+};
+
+// ���л����������ο���
+// https://www.hello-algo.com/chapter_tree/array_representation_of_tree/
+// �������������ʾ��
+// [1, 2, 3, 4, None, 6, 7, 8, 9, None, None, 12, None, None, 15]
+// ��������������ʾ��
+//             /������ 15
+//         /������ 7
+//     /������ 3
+//    |    \������ 6
+//    |        \������ 12
+// ������ 1
+//     \������ 2
+//        |    /������ 9
+//         \������ 4
+//             \������ 8
+
+/* ���б������л�Ϊ���������ݹ� */
+/*
+    vectorToTreeDFS ��һ���ݹ麯�������ڽ�һ���������͵����� arr ת��Ϊһ�ö����������������ĸ��ڵ㡣
+    �����IJ������� arr �� i��arr ��һ���洢����ֵ��������i �ǵ�ǰ�ڵ��������е�������
+    �������ȼ�鵱ǰ���� i �Ƿ�Խ����߶�Ӧ��ֵ�Ƿ�Ϊ INT_MAX������ǵĻ�����ʾ��ǰ�ڵ�Ϊ�սڵ㣬�������� nullptr��
+    �����ǰ�ڵ㲻Ϊ�գ������ᴴ��һ���µ� TreeNode ���󣬲��� arr[i] ��ֵ�����ڵ�� val ��Ա������
+    Ȼ�󣬺�����ݹ���� vectorToTreeDFS ������������ǰ�ڵ������������������������������Ϊ 2 * i + 1��������������Ϊ 2 * i + 2���ݹ���õ�Ŀ���ǽ� arr �е�Ԫ�����ת��Ϊ���Ľڵ㣬�������ڵ�֮��ĸ��ӹ�ϵ��
+    ��󣬺������ظ��ڵ㣬���������������������ת�����̡�
+    �������ʹ���������������DFS���ķ�ʽ��������������ͨ���ݹ�����������������δ���ÿ���ڵ㣬�������������Ķ������ṹ��
+*/
+TreeNode *vectorToTreeDFS(vector<int> &arr, int i)
+{
+    if (i < 0 || i >= arr.size() || arr[i] == INT_MAX)
+    {
+        return nullptr;
+    }
+    TreeNode *root = new TreeNode(arr[i]);
+    root->left = vectorToTreeDFS(arr, 2 * i + 1);  // �ݹ鹹��������
+    root->right = vectorToTreeDFS(arr, 2 * i + 2); // �ݹ鹹��������
+    return root;                                   // ���ظ��ڵ�
+}
+
+/* ���б������л�Ϊ������ */
+TreeNode *vectorToTree(vector<int> arr)
+{
+    return vectorToTreeDFS(arr, 0);
+}
+
+/* �����������л�Ϊ�б����ݹ� */
+/*
+treeToVecorDFS ��һ���ݹ麯�������ڽ��������Ľڵ�ֵ�����������������DFS����˳��洢��һ�������С�
+
+�����IJ���������
+
+root��ָ��ǰ�ڵ��ָ�룬��ʾ��ǰ�ݹ�Ľڵ㡣
+i����ʾ��ǰ�ڵ��������е�����λ�á�
+res���洢�ڵ�ֵ�����������á�
+������ʵ���߼����£�
+
+���ȣ���鵱ǰ�ڵ��Ƿ�Ϊ�ա����Ϊ�գ���ʾ�Ѿ�������Ҷ�ӽڵ��սڵ㣬ֱ�ӷ��ء�
+Ȼ��ͨ��һ��ѭ���������� res ��չ���㹻�ij��ȣ��Ա��ܹ��洢��ǰ�ڵ��ֵ��ѭ�������� i ���ڵ������� res �Ĵ�С��
+������ res �У�������Ϊ i ��λ�õ�ֵ����Ϊ��ǰ�ڵ��ֵ��
+�ݹ���� treeToVecorDFS �������ֱ�����ǰ�ڵ�����ӽڵ�����ӽڵ㡣�������ӽڵ㣬����λ��Ϊ 2 * i + 1���������ӽڵ㣬����λ��Ϊ 2 * i + 2��
+��������������ǽ��������Ľڵ�ֵ�����������������˳��洢��һ�������У��������ں��������ݴ����������
+*/
+void treeToVecorDFS(TreeNode *root, int i, vector<int> &res)
+{
+    if (root == nullptr)
+        return;
+    while (i >= res.size())
+    {
+        res.push_back(INT_MAX); // ��ʼ��Ϊ INT_MAX
+    }
+    res[i] = root->val;
+    treeToVecorDFS(root->left, 2 * i + 1, res);
+    treeToVecorDFS(root->right, 2 * i + 2, res);
+}
+
+/* �����������л�Ϊ�б� */
+vector<int> treeToVecor(TreeNode *root)
+{
+    vector<int> res;
+    treeToVecorDFS(root, 0, res);
+    return res;
+}
+
+/* �ͷŶ������ڴ� */
+void freeMemoryTree(TreeNode *root)
+{
+    if (root == nullptr)
+        return;
+
+    // ��Ҫ���εݹ��ͷ������������ڴ棬���ͷŸ��ڵ���ڴ�
+    freeMemoryTree(root->left);
+    freeMemoryTree(root->right);
+    delete root;
+}
diff --git a/utils/vertex.hpp b/utils/vertex.hpp
new file mode 100644
index 0000000..d40316d
--- /dev/null
+++ b/utils/vertex.hpp
@@ -0,0 +1,42 @@
+/**
+ * File: vertex.hpp
+ * Created Time: 2023-03-02
+ * Author: krahets (krahets@163.com)
+ */
+
+#pragma once // ��ֹͷ�ļ����ظ�����
+
+#include <vector>
+
+using namespace std;
+
+/* ������ */
+struct Vertex
+{
+    int val;
+    Vertex(int x) : val(x)
+    {
+    }
+};
+
+/* ����ֵ�б� vals �����ض����б� vets */
+vector<Vertex *> valsToVets(vector<int> vals)
+{
+    vector<Vertex *> vets;
+    for (int val : vals)
+    {
+        vets.push_back(new Vertex(val));
+    }
+    return vets;
+}
+
+/* ���붥���б� vets ������ֵ�б� vals */
+vector<int> vetsToVals(vector<Vertex *> vets)
+{
+    vector<int> vals;
+    for (Vertex *vet : vets)
+    {
+        vals.push_back(vet->val);
+    }
+    return vals;
+}