MYQUEUE.h

#include <bits/stdc++.h>

using namespace std;

template <typename N> class NodeQueue
{

public:
    N value;
    NodeQueue *next;

    NodeQueue(N val)
    {
        value = val;
        next = NULL;
    }
};

template < typename Q> class Queue
{
    NodeQueue <Q> *front;
    NodeQueue <Q> *rear;

public:
    Queue()
    {
        front = NULL;
        rear = NULL;
    }

    // enqueue --> push (val)

    void push(Q val)
    {

        NodeQueue <Q> *newNode = new NodeQueue <Q> (val);

        if (front == NULL)
        {
            front = newNode;
            rear = newNode;
            return;
        }

        rear->next = newNode;
        rear = rear->next;
    }

    // deque --> pop ()

    Q pop()
    {
        Q chk;
        if (rear == NULL)
        {
            cout << "Queue Underflow | There is no element in the Queue" << endl;
            return chk;
        }
        NodeQueue <Q> *delNode;
        delNode = front;
        front = front->next;
        if (front == NULL)
        {
            rear = NULL;
        }
        chk = delNode->value;
        delete delNode;
        return chk;
    }

    // peek ---> front() back()

    Q Front()
    {

        Q chk;
        chk = front->value;
        return chk;
    }

    Q Back()
    {

        Q chk;
        chk = rear->value;
        return chk;
    }

    // empty ---> empty()
    bool empty()
    {

        if (front == NULL && rear == NULL)
            return true;
        else
            return false;
    }
};