#include <stdio.h>

#include <stdlib.h>

struct node {

    int data;

    struct node* prev;

    struct node* next;

};

struct node* head = NULL;

void input(int);

void traverseForward();

void traverseBackward();

int main()

{

    int n;

    printf("Enter the number of nodes: ");

    scanf("%d", &n);

    input(n);

    traverseForward();

    traverseBackward();

    return 0;

}

void input(int n)

{

    int d;

    struct node *temp = NULL;

    struct node *newnode = NULL;

    for (int i = 1; i <= n; i++)

    {

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

        if (newnode == NULL)

        {

            printf("Memory allocation failed");

            return;

        }

        printf("Enter the value for node %d: ", i);

        scanf("%d", &d);

        newnode->data = d;

        newnode->prev = NULL;

        newnode->next = NULL;

        if (head == NULL)

        {

            head = newnode;

            temp = head;

        }

        else

        {

            temp->next = newnode;

            newnode->prev = temp;

            temp = newnode;

        }

    }

}

void traverseForward()

{

    struct node *temp = head;

    printf("\nForward traversal:\n");

    while (temp != NULL)

    {

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

        temp = temp->next;

    }

    printf("\n");

}

void traverseBackward()

{

    struct node *temp = head;

    if (temp == NULL) {

        printf("Doubly linked list is empty.\n");

        return;

    }

    while (temp->next != NULL) {

        temp = temp->next;

    }

    printf("Backward traversal:\n");

    while (temp != NULL)

    {

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

        temp = temp->prev;

    }

    printf("\n");

}