QUEUE USING POINTERS by smd

-

 program:


#include <stdio.h>

#include <stdlib.h>


int count = 0;


struct node {

    int data;

    struct node *next;

};  


struct node *front = NULL, *rear = NULL, *newn, *temp;


void enqueue() {

    int x;

    printf("Enter enqueue value: ");

    scanf("%d", &x);


    newn = (struct node*)malloc(sizeof(struct node));

    newn->data = x;

    newn->next = NULL;


    if (front == NULL && rear == NULL) {

        front = rear = newn;

    } else {

        rear->next = newn;

        rear = newn;

    }

    count++;

}


void dequeue() {

    if (count == 0) {

        printf("Queue is underflow\n");

    } else {

        printf("%d is deleted\n", front->data);

        temp = front;

        front = front->next;

        free(temp);

        count--;

        if (front == NULL) {  // If queue becomes empty condition after dequeue

            rear = NULL;

        }

    }

}


void display() {

    if (count == 0) {

        printf("Queue is empty\n");

    } else {

        temp = front;

        printf("Queue elements are: ");

        while (temp != NULL) {

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

            temp = temp->next;

        }

        printf("NULL\n");

    }

}


int main() {

    int choice = 0;

    while (choice != 4) {

        printf("\nChoose an option:\n");

        printf("1. Enqueue\n2. Dequeue\n3. Display\n4. Exit\n");

        scanf("%d", &choice);

        switch (choice) {

            case 1:

                enqueue();

                break;

            case 2:

                dequeue();

                break;

            case 3:

                display();

                break;

            case 4:

                printf("Exiting.....\n");

                break;

            default:

                printf("Invalid entry\n");

                break;

        }

    }

    return 0;

}














output:



Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

1

Enter enqueue value: 10


Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

1

Enter enqueue value: 20


Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

1

Enter enqueue value: 30


Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

3

Queue elements are: 10->20->30->NULL


Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

2

10 is deleted


Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

2

20 is deleted


Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

3

Queue elements are: 30->NULL


Choose an option:

1. Enqueue

2. Dequeue

3. Display

4. Exit

4

Exiting...





Comments

Post a Comment

Popular posts from this blog

SINGLE LINKED LIST by smd

-
#include <stdio.h> #include <stdlib.h> int count = 0; struct node {       int data;       struct node *next; }  *head = NULL, *newnode, *trav; void create_list() {       int value;       struct node *temp;       newnode = (struct node *)malloc(sizeof(struct node));       printf("Enter the value to be inserted: ");       scanf("%d", &value);       newnode->data = value;       newnode->next = NULL;       if (head == NULL) {           head = newnode;       } else {           temp = head;           while (temp->next != NULL)               temp = temp->next;           temp->next = newnode;       }       count++; } void insert_at_beg...
Read more

CLL by smd

-
PROGRAM #include <stdio.h> #include <stdlib.h> int count = 0; struct node {  int data; struct node *next; }; struct node *head = NULL, *newnode, *temp; void create_circle_linked_list(); void insert_at_begin(); void insert_at_end(); void insert_at_specific_point(); void delete_at_begin(); void delete_at_end(); void delete_at_specific_point(); void display(); void create_circle_linked_list()  {  int value; printf("Enter the value to be inserted: "); scanf("%d", &value); newnode = (struct node*)malloc(sizeof(struct node)); newnode->data = value; if (head == NULL)  {  head = newnode;  newnode->next = head;  } else  {  temp = head;  while (temp->next != head) temp = temp->next; temp->next = newnode; newnode->next = head;     }     count++; } void insert_at_begin()  { int value;  printf("Enter the value to be inserted: "); scanf("%d", &value); newnode = (struct node*)malloc(si...
Read more

QUEUE USING ARRAYS by smd

-
 #include<stdio.h> #define size 100 int queue[size]; int front = -1, rear = -1; void enqueue(int x)  {     if (rear == size - 1)      {         printf("Queue is overflow\n");     } else      {         if (front == -1)          {             front = 0; // Initialize front if queue was empty         }         rear++;         queue[rear] = x;         printf("%d inserted sucessfully\n", x);     } } void dequeue()  {     if (front == -1 || front > rear)      {         printf("Queue is underflow\n");     } else      {         printf("%d deleted successfully\n", queue[front]);         front++;         if (front ...
Read more