Program for circular Queue.

#include conio.h
#include stdio.h
#include process.h
#define max 100

void add();
void del();
void display();
int x, q[max],n,front=-1,r,el,rear=-1,i,item,up;

void add()
{
printf("\nenter element to add");
scanf("%d",&item);
if(front==(rear+1)%n)
printf("\nQueue overflow");
else
{
if (front==-1)
front=rear=0;
else
rear=(rear+1)%n;
q[r]=item;
}
}

void del()
{
{
if (front==-1)
printf("\nqueue is empty");
exit(1);
}
item=q[front];
if (front==rear)
{
front=rear=-1;
}
else
front=(front+1)%n;
printf("\n element deleted");
}

void display()
{
printf("\nelements in queue:");
for(i=front;i<=rear;i++)
{
printf("%d",q[i]);
}
}
void main()
{
int y=1;
clrscr();
printf("\nenter the size of queue");
scanf("%d",&n);
while(y==1)
{
printf("\nenter your choice");
printf("\n1.Accept\n2.Delete\n3.Display\n4.exit");
scanf("%d",&x);
switch (x)
{
case 1: add();
break;
case 2: del();
break;
case 3: display();
break;
case 4: exit(1);
break;
default:printf("\invalid data");
break;
}
printf("\nenter 1 to continue & 0 to exit");
scanf("%d" ,&y) ;
}
getch();
}