Dynamic Implementation of Queue in C++ using linked list

Dynamic Implementation of Queue in C++ using linked list

#include <iostream.h>

#include <conio.h>

class queue

{

    struct node

    {

        int info;

        node *next;

    }*rear,*front;

    public:

        queue(){rear=front=NULL;}

        void push();

        void pop();

        void display();

};

void queue::push()

{

    int data;

    node *newnode;

    newnode=new node;

    cout<<"Enter the data"<<endl;

    cin>>data;

    newnode->info=data;

    newnode->next=NULL;

    if(rear==NULL)

    {

        front=newnode;

        rear=newnode;

    }

    else

    {

        rear->next=newnode;

        rear=newnode;

    }

}

void queue::pop()

{

    node *temp=front;

    if(front==NULL && rear==NULL) cout<<"Queue is empty"<<endl;

    else

    {

        front=temp->next;

        cout<<"The data is:"<<temp->info;

    }

    delete temp;

    if(front==NULL) rear=NULL;

}

void queue::display()

{

    int a=0;

    node *temp=front;

    cout<<"The items in the queueare"<<endl;

    while(temp!=NULL)

    {

        a++;

        cout<<a<<"."<<temp->info<<endl;

        temp=temp->next;

    }

    if(a==0)

    {

        clrscr();

        cout<<"Queue is empty";

    }

}

void main()

{

    int ch;

    queue a;

    do

    {

        clrscr();

        cout<<"Menu"<<endl;

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

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

        cout<<"3.Display"<<endl;

        cout<<"4.Exit"<<endl;

        cout<<"Enter ur choice:";

        cin>>ch;

        switch(ch)

        {

            case 1:

                a.push();

                break;

            case 2:

                a.pop();

                break;

            case 3:

                a.display();

                break;

            case 4:

                break;

            default:

                cout<<"Out of menu"<<endl;

                break;

        }

        getch();

    }while(ch!=4);

}