From 994963d919f4a8e879a060db888870858d775a3b Mon Sep 17 00:00:00 2001
From: flykhan <liubo666666@outlook.com>
Date: Wed, 2 Aug 2023 19:22:52 +0800
Subject: [PATCH] day7

---
 README.md            |  6 ++++++
 day8/stl_code/d4.cpp | 51 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 day8/stl_code/d4.cpp

diff --git a/README.md b/README.md
index b3ff383..7f55c90 100644
--- a/README.md
+++ b/README.md
@@ -9,3 +9,9 @@
 #### day3: 对象的构造与析构, 构造函数的分类与调用, 拷贝构造函数的调用时机, 构造函数的调用规则, 深拷贝和浅拷贝, 多个对象的构造和析构(初始化列表, 类对象作为成员), explicit 关键字(禁止隐式转换), 动态创建对象(malloc/realloc/calloc 在堆中创建空间, new 关键字), 扩展 new 和 delete,
 
 #### day4: static 静态成员, 类的单例设计模式, 对象的存储（this 指针与链式编程, const 修饰成员函数与类对象）, 友元, 运算符重载
+
+#### day5: =运算符的重载, () 函数调用重载, `注意: &&和|| 无法重载`,
+
+#### day6: 多继承（同属一个超级父类）产生的问题, 多态,抽象类, 虚函数(virtual)与纯虚函数, 接口类的多继承, override-overload-redefined 的区别, 函数模版, 普通函数与带泛型函数的区别
+
+#### day7: 函数模板, 类模板, 类模板与友元一起使用的情况, 类型转换函数(static_cast, dynamic_cast, const_cast, reinterpret_cast)
diff --git a/day8/stl_code/d4.cpp b/day8/stl_code/d4.cpp
new file mode 100644
index 0000000..f83c391
--- /dev/null
+++ b/day8/stl_code/d4.cpp
@@ -0,0 +1,51 @@
+// vector 的嵌套使用示例
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    vector<vector<int> > vs; // 嵌套容器
+    vector<int> v1, v2, v3;
+
+    for (int i = 0; i < 9; i++)
+    {
+        switch (i / 3)
+        {
+        case 0:
+            v1.push_back(i + 1);
+            break;
+        case 1:
+            v2.push_back(i + 1);
+            break;
+        case 2:
+            v3.push_back(i + 1);
+            break;
+        }
+    }
+
+    vs.push_back(v1);
+    vs.push_back(v2);
+    vs.push_back(v3);
+    // for (int i = 0; i < vs.size(); i++)
+    // {
+    //     for (int j = 0; j < vs[i].size(); j++)
+    //     {
+    //         cout << vs[i][j] << " ";
+    //     }
+    //     cout << endl;
+    // }
+
+    vector<vector<int> >::iterator it;
+    for (it = vs.begin(); it != vs.end(); it++)
+    {
+        vector<int>::iterator it2;
+        for (it2 = (*it).begin(); it2 != (*it).end(); it2++)
+        {
+            cout << *it2 << " ";
+        }
+        cout << endl;
+    }
+
+    return 0;
+}