C Program For Deleting A Node In A Doubly Linked List

// C program to implement
// the above approach
#include <stdio.h>
#include <stdlib.h>

// A node of the doubly linked list 
struct Node 
{
    int data;
    struct Node* next;
    struct Node* prev;
};

/* Function to delete a node in a Doubly 
   Linked List. head_ref --> pointer to 
   head node pointer. del  -->  pointer 
   to node to be deleted. */
void deleteNode(struct Node** head_ref, 
                struct Node* del)
{
    // Base case 
    if (*head_ref == NULL || del == NULL)
        return;

    // If node to be deleted is head node 
    if (*head_ref == del)
        *head_ref = del->next;

    /* Change next only if node to be deleted 
       is NOT the last node */
    if (del->next != NULL)
        del->next->prev = del->prev;

    /* Change prev only if node to be deleted 
       is NOT the first node */
    if (del->prev != NULL)
        del->prev->next = del->next;

    // Finally, free the memory occupied by del
    free(del);
    return;
}

// UTILITY FUNCTIONS 
/* Function to insert a node at the 
   beginning of the Doubly Linked List */
void push(struct Node** head_ref, 
          int new_data)
{
    // Allocate node 
    struct Node* new_node = 
           (struct Node*)malloc(sizeof(struct Node));

    // Put in the data  
    new_node->data = new_data;

    /* Since we are adding at the beginning,
       prev is always NULL */
    new_node->prev = NULL;

    // Link the old list of the new node 
    new_node->next = (*head_ref);

    // Change prev of head node to new node 
    if ((*head_ref) != NULL)
        (*head_ref)->prev = new_node;

    // Move the head to point to the new node 
    (*head_ref) = new_node;
}

/* Function to print nodes in a given doubly 
   linked list. This function is same as 
   printList() of singly linked list */
void printList(struct Node* node)
{
    while (node != NULL) 
    {
        printf("%d ", node->data);
        node = node->next;
    }
}

// Driver code
int main()
{
    // Start with the empty list 
    struct Node* head = NULL;

    /* Let us create the doubly 
       linked list 10<->8<->4<->2 */
    push(&head, 2);
    push(&head, 4);
    push(&head, 8);
    push(&head, 10);

    printf(
    "Original Linked list ");
    printList(head);

    /* Delete nodes from the doubly 
       linked list */
    // Delete first node
    deleteNode(&head, head); 

    // Delete middle node
    deleteNode(&head, head->next); 

    // Delete last node
    deleteNode(&head, head->next); 

    /* Modified linked list will be 
       NULL<-8->NULL */
    printf(
    "Modified Linked list ");
    printList(head);

    getchar();
}