STL之map的简单用法

#include<iostream>
#include<map>
using namespace std;
int main() {
    map<int, int>m;
    int n, t, s;
    /*cout << "您要输入几个键值对?" << endl;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> t >> s;
        m[t] = s;
        //或者写成: m.insert({t,s});
    }

    for (auto j : m) {
        cout << j.first << " " << j.second << endl;
    }
    */

    /**/
    //如何记录键出现了几次?
    cout << "您要输入几个键值对?" << endl;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> t ;
        m[t] ++;
    }
    for (auto j : m) {
        cout << j.first << "出现了 " << j.second <<"次" << endl;
    }

    m.erase(1);//删除键值对,只需要删除键就OK了
    m.clear();//清空所有键值对
    //m.size();===>算出有多少组键值对
    //m.count(1);=====>找出键为1的值是多少

    system("pause");
    return 0;
}