/* Program that implements queue as an array. */

/* Program that implements queue as an array. */
#include <stdio.h>
#include <conio.h>
#define MAX 10
void addq ( int *, int, int *, int * ) ;
int delq ( int *, int *, int * ) ;
void main( )
{
 int arr[MAX] ;
 int front = -1, rear = -1, i ;
 clrscr( ) ;
 addq ( arr, 23, &front, &rear ) ;
 addq ( arr, 9, &front, &rear ) ;
 addq ( arr, 11, &front, &rear ) ;
  addq ( arr, 32, &front, &rear ) ;
 i = delq ( arr, &front, &rear ) ;
 printf ( "\nItem deleted: %d", i ) ;
 i = delq ( arr, &front, &rear ) ;
 printf ( "\nItem deleted: %d", i ) ;
 i = delq ( arr, &front, &rear ) ;
 printf ( "\nItem deleted: %d", i ) ;
 getch( ) ;
}
/* adds an element to the queue */
void addq ( int *arr, int item, int *pfront, int *prear  )
{
 if ( *prear == MAX - 1 )
 {
  printf ( "\nQueue is full." ) ;
  return ;
 }
 ( *prear )++ ;
 arr[*prear] = item ;
 if ( *pfront == -1 )
  *pfront = 0 ;
}
/* removes an element from the queue */
int delq ( int *arr, int *pfront, int *prear )
{
 int data ;
 if ( *pfront == -1 )
 {
  printf ( "\nQueue is Empty." ) ;
  return NULL ;
 }
 data = arr[*pfront] ;
 arr[*pfront] = 0 ;
 if ( *pfront == *prear )
   *pfront = *prear = -1 ;
 else
   ( *pfront )++ ;
 return  data ;
}