#include<iostream.h>
#include<conio.h>
#include<stdlib.h>
void
insert_element(void);
int
Delete(void);
void
display(void);
struct node
{
int data;
struct node
*link;
}*f=NULL,*r=NULL;
void main()
{
int choice,x;
clrscr();
cout<<"---------QUEUE
----"<<endl;
cout<<"press 1. insert
the element in the begning"<<endl;
cout<<"press 2. delete
the element from the begning"<<endl;
cout<<"press 3.
display queue"<<endl;
cout<<"press 4.
EXIT"<<endl;
while(1)
{
cout<<"enter
your choice:-";
cin>>choice;
switch(choice)
{
case 1:
insert_element();
break;
case 2:
x=Delete();
cout<<"
deleted number is:-"<<x<<endl;
break;
case 3:
cout<<"QUEUE
IS"<<endl;
display();
break;
case 4:
exit(0);
break;
default:
cout<<"plz enter correct choice";
break;
}//end of switch case
getch();
}//end of while
}//end of main
void insert_element()
{
char ch;
do
{
struct node
*temp;
temp=new node;
cout<<"enter
data:-"; //insert a node in the
circular queue
cin>>temp->data;
if(r==NULL
&& f==NULL)
{
temp->link=temp;
r=temp;
f=temp;
}
else
{
temp->link=f;
r->link=temp;
f=temp;
}
cout<<"do
you want to insert more node(y/n):-";
cin>>ch;
}while(ch=='y');
}//end of function
int Delete()
{
struct node
*temp;
int x;
if(f==NULL
&& r==NULL)
{
cout<<"
no element for deletion";
}
else //delete a node from the
circular queue
{
x=f->data;
temp=f;
f=f->link;
r->link=f;
delete(temp);
}
return(x);
}//end of function
void display()
{
struct node *ptr;
ptr=f; //display a queue
while(ptr->link!=f)
{
cout<<"
"<<ptr->data;
ptr=ptr->link;
}
cout<<"
"<<ptr->data;
cout<<endl;
}//end of function
