题解 | 玩家积分榜系统

#include <iostream>
#include <unordered_map>
#include <string>
using namespace std;
//利用哈希表键为玩家名，值为积分
unordered_map<string , int> gamePlayer;
void insertOrUpdateScore(const string &name, int score)
{
    // TODO: 实现插入或更新逻辑
    gamePlayer[name] = score;
    cout << "OK" <<endl;
}

void queryScore(const string &name)
{
    // TODO: 实现查询逻辑
    if (gamePlayer.count(name)){
        cout << gamePlayer[name]<<endl;
    }else {
        cout <<"Not found"<<endl;
    }

}

void deletePlayer(const string &name)
{
    // TODO: 实现删除逻辑
      if (gamePlayer.count(name)){
             gamePlayer.erase(name);
             cout <<"Deleted successfully"<<endl;
    }else {
        cout <<"Not found"<<endl;
    }

}

void countPlayers()
{
    // TODO: 实现统计逻辑
   
    // for (auto it = gamePlayer.begin(); it != gamePlayer.end(); it ++){
    //     sum++;
    // }
    cout << gamePlayer.size() <<endl;
}

























































































































































































































int main()
{
    // 提高输入输出效率 (可选)
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int q;
    cin >> q;

    while (q--)
    {
        int op;
        cin >> op;

        if (op == 1)
        {
            string name;
            int score;
            cin >> name >> score;
            insertOrUpdateScore(name, score);
        }
        else if (op == 2)
        {
            string name;
            cin >> name;
            queryScore(name);
        }
        else if (op == 3)
        {
            string name;
            cin >> name;
            deletePlayer(name);
        }
        else if (op == 4)
        {
            countPlayers();
        }
    }

    return 0;
}