Given a linked list, print reverse of it using a recursive function. For example, if the given linked list is 1->2->3->4, then output should be 4->3->2->1.
Note that the question is only about printing the reverse. To reverse the list itself see this
Difficulty Level: Rookie
Algorithm:
printReverse(head) 1. call print reverse for head->next 2. print head->data
Implementation:
C
// C program to print reverse // of a linked list #include<stdio.h> #include<stdlib.h> // Link list node struct Node
{ int data;
struct Node* next;
}; // Function to reverse the linked list void printReverse( struct Node* head)
{ // Base case
if (head == NULL)
return ;
// Print the list after head node
printReverse(head->next);
// After everything else is printed,
// print head
printf ( "%d " , head->data);
} // UTILITY FUNCTIONS /* Push a node to linked list. Note that this function
changes the head */
void push( struct Node** head_ref,
char new_data)
{ // Allocate node
struct Node* new_node =
( struct Node*) malloc ( sizeof ( struct Node));
// Put in the data
new_node->data = new_data;
// Link the old list of the
// new node
new_node->next = (*head_ref);
// Move the head to point to the
// new node
(*head_ref) = new_node;
} // Driver code int main()
{ // Create linked list 1->2->3->4
struct Node* head = NULL;
push(&head, 4);
push(&head, 3);
push(&head, 2);
push(&head, 1);
printReverse(head);
return 0;
} |
Output:
4 3 2 1
Time Complexity: O(n)
Space Complexity: O(n) for call stack since using recursion
Please refer complete article on Print reverse of a Linked List without actually reversing for more details!