Page 173 - DCAP201_FUNDAMENTALS_OF_DATA_STRUCTURES

Fundamentals of Data Structures

Notes NULL value for it, then its a “queue overflow” state, so quit; else go to step (b)
(b) add the new value for the queue position pointed by the “rear”
Algorithm for deletion of an element from the circular queue:
Step-1: If the queue is empty then say “queue is empty” and quit; else continue

Step-2: Delete the “front” element
Step-3: If the “front” is pointing to the last position of the queue then go to step-4 else go to
step-5

Step-4: Make the “front” point to the first position in the queue and quit
Step-5: Increment the “front” position by one.

10.3.1 Array Implementation of a Circular Queue

A circular queue can be implemented using arrays or linked lists. Program given below gives
the array implementation of a circular queue.
#include “stdio.h”
void add(int);
void deleteelement(void);
int max=10; /*the maximum limit for queue has been set*/
static int queue[10];
int front=0, rear=-1; /*queue is initially empty*/
void main()
{
int choice,x;
printf (“enter 1 for addition and 2 to remove element front the queue
and 3 for exit”);
printf(“Enter your choice”);
scanf(“%d”,&choice);
switch (choice)
{
case 1 :
printf (“Enter the element to be added :”);
scanf(“%d”,&x);
add(x);
break;
case 2 :
deleteelement();
break;
}
}
void add(int y)
{
if (rear == max-1)

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