C++ implementation of front and rear end varying queue

C++ implementation of front and rear end varying queue

#include <iostream.h>

#include <conio.h>

#define size 10

class queue

{

    int q,item[size],rear,front;

    public:

        queue(){q=0;rear=0;front=0;}

        void enqueue();

        void dequeue();

        void display();

};

void queue::enqueue()

{

    int a;

    if(rear>=size) cout<<"The queue is full"<<endl;

    else

    {

        cout<<"Enter a number"<<endl;

        cin>>a;

        item[rear]=a;

        rear++;

        q++;

    }

}

void queue::dequeue()

{

    if(q==0) cout<<"The queue is empty"<<endl;

    else

    {

        cout<<"The number is"<<endl<<item[front];

        front++;

        q--;

    }

}

void queue::display()

{

    if(q==0) cout<<"Empty";

    else{

    cout<<"The numbers in queue are"<<endl;

    for(int i=front;i<rear;i++)

    {

        cout<<item[i]<<'\t';

    }

    }

}

void main()

{

    queue a1;

    int ch;

    do{

    clrscr();

    cout<<"Menu"<<endl;

    cout<<"1.Enqueue operation"<<endl;

    cout<<"2.Dequeue operation"<<endl;

    cout<<"3.Display all"<<endl;

    cout<<"Enter your choice"<<endl;

    cin>>ch;

    switch(ch)

    {

        case 1:

            a1.enqueue();

            break;

        case 2:

            a1.dequeue();

            break;

        case 3:

            a1.display();

            break;

    }

    getch();

    }while(ch<4);

}