Circular Queue in Data Structure in C using Linked List

Here you will get and learn the program code of Circular Queue in Data Structure in C using Linked List.

What is Circular Queue in Data Structure?

Circular Queue in data structure works like a regular queue but with a circular arrangement of elements. It has a fixed size and consists of a front and rear end. When elements are dequeued (removed), the front moves forward, making space for new elements. It’s efficient for tasks with a fixed buffer size or when you want to reuse empty spaces.

It’s commonly used in situations where a continuous flow of data is required, like computer memory management and scheduling algorithms.

Program Code of Circular Queue in Data Structure in C

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//Circular Queue in Data Structure in C using Linked List

#include<stdio.h>

#include<stdlib.h>

struct queue{

int info;

struct queue *link;

};

struct queue *front=NULL,*rear=NULL;

int count=0;

//insert data in queue

void push(int n)

{

struct queue *newnode;

newnode=(struct queue*)malloc(sizeof(struct queue));

newnode->info=n;

newnode->link=NULL;

if(count==0)

front=newnode;

else

rear->link=newnode;

rear=newnode;

rear->link=front;

count++;

}

//Delete data in queue

int pop(void)

{

int n;

struct queue *temp;

if(count==0)

return (-1);

count--;

if(front==rear)

{

n=front->info;

free(front);

front=NULL;

rear=NULL;

}else

{

temp= front ;

n = temp-> info ;

front = front -> link ;

rear -> link = front ;

free ( temp ) ;

}

return n;

}

// count size of queue

int size(void)

{

return count;

}

//print data

void display(void)

{

struct queue *temp;

int i;

if(count==0)

printf("Queue is Empty");

else

{

temp=front;

for(i=0;i<count;i++)

{

printf("%d ",temp->info);

temp=temp->link;

}

printf("\n");

}

int main()

{

int n,ch=10;

while(ch!=0)

{

printf("\nCircular Queue using Linked List\n");

printf("1.Push\n");

printf("2.Pop\n");

printf("3.Size of Queue\n");

printf("4.Display List\n");

printf("0.EXIT\n");

printf("\nEnter Your Choice : ");

scanf("%d",&ch);

switch(ch)

{

case 1:

{

printf("Enter number to insert : \n");

scanf("%d",&n);

push(n);

break;

}

case 2:

{

n=pop();

if(n==-1)

printf("Queue is empty\n");

else

printf("%d Number is Poped\n",n);

break;

}

case 3:

{

n=size();

printf("Size of queue is %d\n",n);

break;

}

case 4:

{

printf("Queue is --> ");

display();

}

case 0:

break;

default:

printf("Wrong Choice! \n");

break;

}

Output