這道題一開始一直超時，後來看了大神的發現要用unordered_map，然後還是不行，把cout改成printf，居然過了。。。時間真的掐得緊

#include <iostream>
#include <stdlib.h>
#include <string>
#include<algorithm>
#include<vector>
#include<cmath>
#include<map>

#include <unordered_map>

using namespace std;

struct
 
 stu {
    string cnum;
    int score;
};

struct site {
    int num;
    string s;
};

bool cmp1(stu x, stu y) {
    if (x.score != y.score) {
        return x.score > y.score;
    }
    else {
        return x.cnum < y.cnum;
    }
}

bool cmp2(site x, site y) {
    if (x.num != y.num) {
        
 
return x.num > y.num;
    }

    else {
        return x.s < y.s;
    }
}

int main(){

    int m, n;
    cin >> n >> m;
    vector<stu> arr;
    for (int i = 0; i < n; i++) {
        stu s;
        cin >> s.cnum >> s.score;
        arr.push_back(s);
    }

    
 
for (int i = 0; i < m; i++) {
        int type;
        cin >> type;
        if (type == 1) {
            char level;
            cin >> level;
            int num = 0;
            sort(arr.begin(), arr.end(), cmp1);
            cout << "Case" << ' ' << i + 1 << ": " << type << ' ' << level<<endl;
            for (int j = 0; j < arr.size(); j++) {
                if (arr[j].cnum[0] == level) {
                    printf("%s %d\n", arr[j].cnum.c_str(), arr[j].score);
                    num++;
                }
            }

            if (num == 0) {
                cout << "NA" << endl;
            }
        }


        if (type == 2) {
            string site;
            cin >> site;
            int num = 0, total = 0;
            for (int j = 0; j < arr.size(); j++) {
                if (arr[j].cnum.substr(1, 3) == site) {
                    num++;
                    total += arr[j].score;
                }
            }

            cout << "Case" << ' ' << i + 1 << ": " << type << ' ' << site<<endl;

            if (num == 0) {
                cout << "NA" << endl;
            }
            else {
                cout << num << ' ' << total << endl;
            }
        }

        if (type == 3) {
            string date;
            cin >> date;
            unordered_map<string, int> m1;
            vector<site> arr1;
            for (int j = 0; j < arr.size(); j++) {
                if (arr[j].cnum.substr(4, 6) == date) {
                    m1[arr[j].cnum.substr(1, 3)]++;
                }
            }

            for (auto it : m1) {
                site temp;
                temp.s = it.first;
                temp.num = it.second;
                arr1.push_back(temp);
            }

            sort(arr1.begin(), arr1.end(), cmp2);
            cout << "Case" << ' ' << i + 1 << ": " << type << ' ' << date << endl;

            if (arr1.size() == 0) {
                cout << "NA" << endl;
            }

            else {
                for (int j = 0; j < arr1.size(); j++) {
                    printf("%s %d\n", arr1[j].s.c_str(), arr1[j].num);
                }
            }
        }
    }


    system("pause");

};