Question

it is c programming problem. help me to do this problem

1. write a insertion function and deletion function for a double-linked list

Answer 1

Here is code:

#include <stdio.h>

#include <stdlib.h>

struct Node

{

int data;

struct Node *next;

struct Node *prev;

};

void deleteNode(struct Node **head_ref, struct Node *del)

{

if (*head_ref == NULL || del == NULL)

return;

if (*head_ref == del)

*head_ref = del->next;

// if its not last element

if (del->next != NULL)

del->next->prev = del->prev;

// if its not first element

if (del->prev != NULL)

del->prev->next = del->next;

free(del);

return;

}

void insertNode(struct Node **head_ref, int new_data)

{

// create new node

struct Node *new_node = (struct Node *)malloc(sizeof(struct Node));

// adding data

new_node->data = new_data;

new_node->prev = NULL;

new_node->next = (*head_ref);

//if not the first node

if ((*head_ref) != NULL)

(*head_ref)->prev = new_node;

// add to new node

(*head_ref) = new_node;

}

// print node

void printList(struct Node *node)

{

while (node != NULL)

{

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

node = node->next;

}

}

int main()

{

struct Node *head = NULL;

insertNode(&head, 2);

insertNode(&head, 6);

insertNode(&head, 9);

insertNode(&head, 10);

printf("\n Linked list \t\t\t: ");

printList(head);

deleteNode(&head, head); // delete 10

deleteNode(&head, head->next->next); // delete 2

printf("\n After removed Linked list \t: ");

printList(head);

}

Output: