Queue

#include<bits/stdc++.h>
using namespace std;

int main(){
    queue<int>q;

    q.push(5); //5
    q.push(2); //5,2
    q.push(7); //5,2,7

    cout<<"front element in queue is : "<<q.front()<<endl; //5

    q.pop();
    //queue now : 2,7
    cout<<"front element in queue is : "<<q.front()<<endl; //2
}