70 lines
1.6 KiB
C++
70 lines
1.6 KiB
C++
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/**
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* File: binary_tree_dfs.cpp
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* Created Time: 2022-11-25
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* Author: krahets (krahets@163.com)
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*/
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#include "../utils/common.hpp"
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// 初始化列表，用于存储遍历序列
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vector<int> vec;
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/* 前序遍历 */
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void preOrder(TreeNode *root) {
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if (root == nullptr)
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return;
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// 访问优先级：根节点 -> 左子树 -> 右子树
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vec.push_back(root->val);
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preOrder(root->left);
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preOrder(root->right);
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}
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/* 中序遍历 */
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void inOrder(TreeNode *root) {
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if (root == nullptr)
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return;
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// 访问优先级：左子树 -> 根节点 -> 右子树
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inOrder(root->left);
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vec.push_back(root->val);
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inOrder(root->right);
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}
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/* 后序遍历 */
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void postOrder(TreeNode *root) {
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if (root == nullptr)
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return;
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// 访问优先级：左子树 -> 右子树 -> 根节点
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postOrder(root->left);
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postOrder(root->right);
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vec.push_back(root->val);
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}
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/* Driver Code */
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int main() {
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/* 初始化二叉树 */
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// 这里借助了一个从数组直接生成二叉树的函数
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TreeNode *root = vectorToTree(vector<int>{1, 2, 3, 4, 5, 6, 7});
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cout << endl << "初始化二叉树\n" << endl;
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printTree(root);
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/* 前序遍历 */
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vec.clear();
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preOrder(root);
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cout << endl << "前序遍历的节点打印序列 = ";
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printVector(vec);
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/* 中序遍历 */
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vec.clear();
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inOrder(root);
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cout << endl << "中序遍历的节点打印序列 = ";
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printVector(vec);
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/* 后序遍历 */
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vec.clear();
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postOrder(root);
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cout << endl << "后序遍历的节点打印序列 = ";
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printVector(vec);
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return 0;
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}
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