(i) Inserting an element in the Queue

(ii) Deleting an element from the Queue

(iii) Displaying the Queue

(iv) Exiting the program

Mumbai University > Computer Engineering > Sem 3 > Data Structures

Marks: 10M

Years: May 2016

/*
 * C to implement QUEUE ADT
 */
#include <stdio.h>
#define MAX 50
int queue_array[MAX];
int rear = - 1;
int front = - 1;
main()
{
    int choice;
    while (1)
    {
        printf("1.Insert element to queue \n");
        printf("2.Delete element from queue \n");
        printf("3.Display all elements of queue \n");
        printf("4.Quit \n");
        printf("Enter your choice : ");
        scanf("%d", &choice);
        switch (choice)
        {
            case 1:
            insert();
            break;
            case 2:
            delete();
            break;
            case 3:
            display();
            break;
            case 4:
            exit(1);
            default:
            printf("Wrong choice \n");
        } /*End of switch*/
    } /*End of while*/
} /*End of main()*/
insert()
{
    int add_item;
    if (rear == MAX - 1)
    printf("Queue Overflow \n");
    else
    {
        if (front == - 1)
        /*If queue is initially empty */
        front = 0;
        printf("Inset the element in queue : ");
        scanf("%d", &add_item);
        rear = rear + 1;
        queue_array[rear] = add_item;
    }
} /*End of insert()*/

delete()
{
    if (front == - 1 || front > rear)
    {
        printf("Queue Underflow \n");
        return ;
    }
    else
    {
        printf("Element deleted from queue is : %d\n", queue_array[front]);
        front = front + 1;
    }
} /*End of delete() */
display()
{
    int i;
    if (front == - 1)
        printf("Queue is empty \n");
    else
    {
        printf("Queue is : \n");
        for (i = front; i <= rear; i++)
            printf("%d ", queue_array[i]);
        printf("\n");
    }
} /*End of display() */

OUTPUT:

1. Insert element to queue
2. Delete element from queue
3. Display all elements of queue
4. Quit

Enter your choice: 1

Inset the element in queue: 10

1. Insert element to queue
2. Delete element from queue
3. Display all elements of queue
4. Quit

Enter your choice: 1

Inset the element in queue: 15

1. Insert element to queue
2. Delete element from queue
3. Display all elements of queue
4. Quit

Enter your choice: 1

Inset the element in queue: 20

1. Insert element to queue
2. Delete element from queue
3. Display all elements of queue
4. Quit

Enter your choice: 1

Inset the element in queue: 30

1. Insert element to queue
2. Delete element from queue
3. Display all elements of queue
4. Quit

Enter your choice: 2

Element deleted from queue is: 10

1. Insert element to queue
2. Delete element from queue
3. Display all elements of queue
4. Quit

Enter your choice: 3

Queue is:15 20 30

1. Insert element to queue
2. Delete element from queue
3. Display all elements of queue
4. Quit

Enter your choice: 4