【蓝桥杯】试题 算法提高 队列操作

#include <iostream>
#include <cstdio>
#include <cstring>
#include <map>
#include <stack>
#include <iomanip>
#include <stack>
#include <algorithm>
using namespace std;
#include <queue>
int main()
{
    //freopen("in.txt","r",stdin);

    queue<int>  q;
    int n;
    cin>>n;
    int a,b;
    while(n--){
        cin>>a;
        if(a==1){
            cin>>b;
            q.push(b);
        }else if(a==2){
            if(q.empty()){
                cout<<"no"<<endl;
                return 0;
            }
            cout<<q.front()<<endl;
            q.pop();
        }else if(a==3){
            cout<<q.size()<<endl;
        }
    }
    return 0;
     
}