What is doubly Linked List? What are its applications?Explain how an element can be deleted from doublylinked list using C program

A doubly linked list is a type of data structure in which each node contains a reference to both the next and previous nodes in the list. This allows for traversal in both directions, forward and backward.

Applications of doubly linked lists include:

1. Implementation of data structures like stacks, queues, and deques.
2. Efficient insertion and deletion operations, especially at the beginning and end of the list.
3. Implementing undo and redo functionality in text editors.
4. Implementing navigation systems in web browsers.

To delete an element from a doubly linked list using a C program, you can follow these steps:

1. Check if the list is empty. If it is, then there is nothing to delete.
2. If the list is not empty, check if the element to be deleted is the first node. If it is, update the head pointer to point to the next node and free the memory of the current node.
3. If the element to be deleted is not the first node, traverse the list until you find the node containing the element.
4. Once you find the node, update the previous node's next pointer to point to the next node and update the next node's previous pointer to point to the previous node.
5. Finally, free the memory of the node containing the element.

Here is an example C program to delete an element from a doubly linked list:

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

struct Node {
    int data;
    struct Node* prev;
    struct Node* next;
};

void deleteNode(struct Node** head, int key) {
    if (*head == NULL) {
        printf("List is empty. Nothing to delete.\n");
        return;
    }

    struct Node* current = *head;

    // Check if the element to be deleted is the first node
    if (current != NULL && current->data == key) {
        *head = current->next;
        if (current->next != NULL) {
            current->next->prev = NULL;
        }
        free(current);
        return;
    }

    // Traverse the list to find the node containing the element
    while (current != NULL && current->data != key) {
        current = current->next;
    }

    // If the element is not found
    if (current == NULL) {
        printf("Element not found in the list.\n");
        return;
    }

    // Update the previous node's next pointer and the next node's previous pointer
    if (current->prev != NULL) {
        current->prev->next = current->next;
    }
    if (current->next != NULL) {
        current->next->prev = current->prev;
    }

    // Free the memory of the node containing the element
    free(current);
}

int main() {
    struct Node* head = NULL;

    // Create a doubly linked list
    // ...

    // Delete an element from the list
    deleteNode(&head, 5);

    // Print the updated list
    // ...

    return 0;
}

In this example, the deleteNode function takes a pointer to the head of the list and the key of the element to be deleted as parameters. It performs the necessary operations to delete the element from the list.