QUEUE OPERATION USING LIKED LIST.

#include<stdio.h>

#include<conio.h>

#include<stdlib.h>

void enq();

void deq();

void display();

main()

{

int n;

printf("\tMENU\n1.ENQUEUE\n2.DEQUEUE\n3.DISPLAY\n4.EXIT\n");

do

{

printf("\nEnter your choice\n");

scanf("%d",&n);

switch(n)

{

case 1:

enq();

break;

case 2:

deq();

break;

case 3:

display();

break;

case 4:

break;

default:

printf("Invalid choice\n");

break;

}

}

while(n!=4);

}

typedef struct node

{

int data;

struct node *link;

}n;

n *front=NULL;

n *rear=NULL;

void enq()

{

int item;

n *temp;

printf("Enter the item\n");

scanf("%d",&item);

temp=(n*)malloc(sizeof(n));

temp->data=item;

temp->link=NULL;

if(rear==NULL)

{

front=temp;

rear=temp;

}

else

{

rear->link=temp;

rear=temp;

}

}

void deq()

{

int item;

if(front==NULL)

printf("Queue is empty\n");

else

{

item=front->data;

printf("The element deleted = %d\n",item);

}

if(front==rear)

{

front=NULL;

rear=NULL;

}

else

front=front->link;

}

void display()

{

n *ptr;

if(front==NULL)

printf("Queue is empty\n");

else

{

ptr=front;

printf("The elements of the queue are :");

while(ptr!=NULL)

{

printf("%d\t",ptr->data);

ptr=ptr->link;

}

}

}

Output:

              MENU

1.ENQUEUE

2.DEQUEUE

3.DISPLAY

4.EXIT

Enter your choice

1

Enter the item

2

Enter your choice

1

Enter the item

3

Enter your choice

1

Enter the item

4

Enter your choice

3

The elements of the queue are :2        3       4

Enter your choice

2

The element deleted = 2

Enter your choice

3

The elements of the queue are :3        4

Enter your choic