829. 模拟队列

Posted 2021-05-20 幽殇默

https://www.acwing.com/problem/content/description/831/

#include<cstdio>
#include<iostream>
using namespace std;
const int N=1e5+10;
int q[N],hh=0,tt=-1;
int x,m;
int main(void)
{
    cin>>m;
    while(m--)
    {
        string op; cin>>op;
        if(op=="push") cin>>x,q[++tt]=x;
        if(op=="pop") hh++;
        if(op=="empty")
        {
            if(hh<=tt) cout<<"NO"<<endl;
            else cout<<"YES"<<endl;
        }
        if(op=="query") cout<<q[hh]<<endl;
    }
}

用STL里的queue

#include<queue>
#include<cstdio>
#include<iostream>
using namespace std;
queue<int> q;
int m,x;
int main(void)
{
    cin>>m;
    while(m--)
    {
        string op; cin>>op;
        if(op=="push") cin>>x,q.push(x);
        if(op=="pop") q.pop();
        if(op=="empty")
        {
            if(q.size()) cout<<"NO"<<endl;
            else cout<<"YES"<<endl;
        }
        if(op=="query") cout<<q.front()<<endl;
    }
}