programming-examples/c/Recursion/C Program to Display the Nodes of a Linked List in Reverse using Recursion.c

/*
 * Recursive C program to reverse nodes of a linked list and display
 * them
 */
#include <stdio.h>
#include <stdlib.h>

struct node
{
    int data;
    struct node *next;
};

void print_reverse_recursive (struct node *);
void print (struct node *);
void create_new_node (struct node *, int );

//Driver Function
int main ()
{
    struct node *head = NULL;
    insert_new_node (&head, 1);
    insert_new_node (&head, 2);
    insert_new_node (&head, 3);
    insert_new_node (&head, 4);
    printf ("LinkedList : ");
    print (head);
    printf ("\nLinkedList in reverse order : ");
    print_reverse_recursive (head);
    printf ("\n");
    return 0;
}

//Recursive Reverse
void print_reverse_recursive (struct node *head)
{
    if (head == NULL)
        {
            return;
        }
    //Recursive call first
    print_reverse (head -> next);
    //Print later
    printf ("%d ", head -> data);
}

//Print the linkedlist normal
void print (struct node *head)
{
    if (head == NULL)
        {
            return;
        }
    printf ("%d ", head -> data);
    print (head -> next);
}

//New data added in the start
void insert_new_node (struct node ** head_ref, int new_data)
{
    struct node * new_node = (struct node *) malloc (sizeof (struct node));
    new_node -> data = new_data;
    new_node -> next = (*head_ref);
    (*head_ref) = new_node;
}