蓝桥杯备考：unordered_map基础用法题 ---学籍管理

我们用unorderedmap绑定名字和成绩，然后进行n次操作 主要是锻炼我们对map接口的用法的理解

#include <iostream>
#include <unordered_map>
using namespace std;unordered_map<string,int> mp;int main()
{int n;cin >> n;while(n--){int op,score;string s;cin >> op;if(op == 1){cin >> s >> score;mp[s] = score;cout << "OK" << endl;}else if(op == 2){cin >> s;if(!mp.count(s)){cout << "Not found" << endl;}else{cout << mp[s] << endl;}}else if(op == 3){cin >> s;if(mp.count(s)){	mp.erase(s);cout << "Deleted successfully" << endl;}elsecout << "Not found" << endl;}else{cout << mp.size() << endl;}}}