Untitled

#include <stdio.h>
#include <stdlib.h>

// Define a Node structure
struct Node {
    int data;
    struct Node* next;
    struct Node* prev;
};

// Function to insert a node at the beginning
void insertAtBeginning(struct Node** head, int data) {
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->data = data;
    newNode->next = *head;
    newNode->prev = NULL;

    if (*head != NULL)
        (*head)->prev = newNode;

    *head = newNode;
}

// Function to insert a node at the end
void insertAtEnd(struct Node** head, int data) {
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    struct Node* temp = *head;
    newNode->data = data;
    newNode->next = NULL;

    if (*head == NULL) {
        newNode->prev = NULL;
        *head = newNode;
        return;
    }

    while (temp->next != NULL)
        temp = temp->next;

    temp->next = newNode;
    newNode->prev = temp;
}

// Function to delete a node from the list
void deleteNode(struct Node** head, int key) {
    struct Node* temp = *head;

    if (*head == NULL) {
        printf("List is empty.\n");
        return;
    }

    while (temp != NULL && temp->data != key)
        temp = temp->next;

    if (temp == NULL) {
        printf("Element not found.\n");
        return;
    }

    if (temp->prev != NULL)
        temp->prev->next = temp->next;
    else
        *head = temp->next;

    if (temp->next != NULL)
        temp->next->prev = temp->prev;

    free(temp);
    printf("Element %d deleted.\n", key);
}

// Function to display the list in forward direction
void displayForward(struct Node* head) {
    struct Node* temp = head;
    printf("Forward List: ");
    while (temp != NULL) {
        printf("%d -> ", temp->data);
        temp = temp->next;
    }
    printf("NULL\n");
}

// Function to display the list in reverse direction
void displayReverse(struct Node* head) {
    struct Node* temp = head;
    if (temp == NULL) {
        printf("List is empty.\n");
        return;
    }

    while (temp->next != NULL)
        temp = temp->next;

    printf("Reverse List: ");
    while (temp != NULL) {
        printf("%d -> ", temp->data);
        temp = temp->prev;
    }
    printf("NULL\n");
}

// Function to search for an element in the list
void search(struct Node* head, int key) {
    struct Node* temp = head;
    int pos = 1;

    while (temp != NULL) {
        if (temp->data == key) {
            printf("Element %d found at position %d\n", key, pos);
            return;
        }
        temp = temp->next;
        pos++;
    }

    printf("Element %d not found in the list.\n", key);
}

// Main function
int main() {
    struct Node* head = NULL;
    int choice, value;

    while (1) {
        printf("\nDoubly Linked List Operations:\n");
        printf("1. Insert at Beginning\n");
        printf("2. Insert at End\n");
        printf("3. Delete Node\n");
        printf("4. Display Forward\n");
        printf("5. Display Reverse\n");
        printf("6. Search\n");
        printf("7. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("Enter value: ");
                scanf("%d", &value);
                insertAtBeginning(&head, value);
                break;
            case 2:
                printf("Enter value: ");
                scanf("%d", &value);
                insertAtEnd(&head, value);
                break;
            case 3:
                printf("Enter value to delete: ");
                scanf("%d", &value);
                deleteNode(&head, value);
                break;
            case 4:
                displayForward(head);
                break;
            case 5:
                displayReverse(head);
                break;
            case 6:
                printf("Enter value to search: ");
                scanf("%d", &value);
                search(head, value);
                break;
            case 7:
                exit(0);
            default:
                printf("Invalid choice! Please try again.\n");
        }
    }
    return 0;
}