Deque in C++ (STL container)

What is deque ? how to insert and delete value from deque


A deque is a double ended queues sequence container of expresion and contraction with both the
ends. they are similar to vectors but are more efficient in case of insertion and deletion
and other opperation.

Deque diclaretion -->

                   std::deque <data type> deq;


Insertion >>

#include<bits/stdc++.h>
using namespace std;
int main()
{
    deque <int> dq;
    dq.push_back(10);
    dq.push_front(20);
    dq.push_back(11);
    dq.push_front(21);

    cout<<"Deque elements are : "<<endl;

    for(int i=0; i<dq.size(); i++)
    {
        cout<<dq[i]<<" ";
    }
    cout<<endl;
    return 0;
}

Deletion >>>

#include<bits/stdc++.h>

using namespace std;

int main()

{

    deque <int> dq;

    dq.push_back(10);

    dq.push_front(20);

    dq.push_back(11);

    dq.push_front(21);

    cout<<"Deque elements are : "<<endl;

    for(int i=0; i<dq.size(); i++)

    {

        cout<<dq[i]<<" ";

    }

    cout<<endl;

    dq.pop_back();

    dq.pop_front();

    cout<<"Deque elements after deletion are : "<<endl;

    for(int i=0; i<dq.size(); i++)

    {

        cout<<dq[i]<<" ";

    }

    cout<<endl;

    return 0;

}