/*5.PROGRAM TO IMPLEMENT AN ORDINARY QUEUE*/
#include<stdio.h>
#include<conio.h>
#define size 5
int f,r=-1;
void OQinsert_rear(int item,int q[])
    {
     if(r==size-1)
	printf("\nQueue Overflow\n");
     else
	q[++r]=item;
    }
void OQdelete_front(int q[])
    {
     if(f>r)
	printf("\nQueue Underflow\n");
     else
	printf("\nDeleted item is %d\n",q[f++]);
     if(f>r)
	f=0,r=-1;
     }
void OQdisplay(int q[])
    {
     int i;
     if(f>r)
      {
	printf("\nQueue is empty\n");
	return;
      }
     else
      {
	printf("\nQueue Contents are\n");
	for(i=0;i<=r;i++)
	  printf("%d\t",q[i]);
      }
    }
void main()
   {
    int ch,item,q[20];
    for(;;)
     {
      clrscr();
      printf("\n1:INSERT\n2:DELETE\n3:DISPLAY\n4:QUIT\n");
      printf("\nEnter ur choice\n");
      scanf("%d",&ch);
	switch(ch)
	  {
	   case 1:
		 printf("\nEnter the Queue element to be inserted\n");
		 scanf("%d",&item);
		 OQinsert_rear(item,q);
		 break;
	   case 2:
		 OQdelete_front(q);
		 break;
	   case 3:
		 OQdisplay(q);
		 break;
	   case 4:
		 exit(0);
	   default :
		printf("invalid choice\n");
	  }
	  getch();
	}
     }