题目描述

思路讲解

队列是先进先出，类比排队买饭

代码展示

#include <iostream>using namespace std;const int N = 100010;int m;
int q[N], hh, tt = -1;int main()
{cin >> m;while (m -- ){string op;int x;cin >> op;if (op == "push"){cin >> x;q[ ++ tt] = x;}else if (op == "pop") hh ++ ;else if (op == "empty") cout << (hh <= tt ? "NO" : "YES") << endl;else cout << q[hh] << endl;}return 0;
}