void map_constructor(){
    //构造方式一：
    map<int,string> intStr0;
    map<int,string> intStr0_2 = map<int, string>();
    
    
    //构造方式二：
    //注意：C++11才开始支持括号初始化 使用{}赋值
    map<int,string> intStr1_0 = map<int, string>{pair<int,string>(3,"world")};
    map<int,string> intStr1_1 = map<int, string>{ {3,"world"}};
    map<int,string> intStr1_2 = { {3,"world"}};
    map<int,string> intStr1_3{ {3,"world"},{4,"earth"}};
}

void map_zengShanGaiCha(){
    
    //map的初始化
    map<int,string> myMap = { {1,"张三"},{2,"李四"}};
    
    
    //增
    cout<<"-----------------增-----------------"<<endl;
    myMap.insert(pair<int,string>(3, "王五"));
    myMap.insert(map<int, string>::value_type(4,"谢六"));
    myMap.insert({5,"田七"});
    //使用[ ]进行单个插入，若已存在键值6，则赋值修改，若无则插入。
    myMap[6] = "冯八";


    
    //查
    cout<<"-----------------查-----------------"<<endl;
    string val1 = myMap[4];
    auto it = myMap.find(4);
    int key2 = it->first;
    string val2 = it->second;
    cout<<"val2 = "<<val2<<endl;
    
    
    //改
    cout<<"-----------------改-----------------"<<endl;
    myMap[4] = "hehe";
    cout<<"myMap[4] = "<<myMap[4]<<endl;
    auto it2 = myMap.find(4);
    it2->second = "ss";
    cout<<"it2->second = "<<it->second<<endl;
    
    
    //删
    cout<<"-----------------删-----------------"<<endl;
    myMap.erase(4);//通过key删除
    myMap.erase(--myMap.end());//通过迭代器删除
    myMap.erase(myMap.begin(),myMap.end());//清空（通过迭代器删除某一范围）
    myMap.clear();
    
    
    //大小
    cout<<"-----------------大小-----------------"<<endl;
    cout<<"size = "<<myMap.size()<<endl;
}

void map_enum(){
    
    map<int, string> myMap={ { 5, "张大" },{ 6, "李五" },{3,"张三"},{4,"李四"}};
    
    /**
     遍历输出+迭代器的使用
     auto自动识别为迭代器类型unordered_map<int,string>::iterator
     
     迭代器就是一种指针的应用！
     begin();是指第一个元素的位置
     end()是指最后一个元素的后面
     */

    
    //迭代器
    auto iterBegin = myMap.begin();//指向第一个键值对的指针
    auto iterEnd = myMap.end();//指向最后一个键值对的后面
    iterEnd--;//指向最后一个元素
    cout<<"iter1->first="<<iterEnd->first<<","<<"iter1->second="<<iterEnd->second<<endl;
    
    //遍历方式一：
    cout<<"---------------遍历方式一---------------"<<endl;
    auto iter = myMap.begin();
    while (iter!=myMap.end()) {
        cout<<iter->first<<","<<iter->second<<endl;
        iter++;
    }
    
    
    //遍历方式二：
    cout<<"---------------遍历方式二---------------"<<endl;
    for(auto it2=myMap.begin();it2!=myMap.end();it2++){
         cout<<it2->first<<","<<it2->second<<endl;
    }
    
    
    //遍历方式三：
    cout<<"---------------遍历方式三---------------"<<endl;
    auto iter3 = myMap.begin();
    for (int i=0; i<myMap.size(); i++,iter3++) {
         cout<<iter3->first<<","<<iter3->second<<endl;
    }
}

void map_sort(){
    
    //map是自带升序的
    //unordered_map 是没有顺序的
    map<int, string> myMap={ { 5, "张大" },{ 6, "李五" },{ 3,"张三"},{ 4,"李四"} };
    for (auto it=myMap.begin(); it!=myMap.end(); it++) {
        cout<<it->first<<","<<it->second<<endl;
    }
}