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 <bits/stdc++.h> using namespace std; /* Link list node */ class Node { public : int data; Node* next; }; /* Function to reverse the linked list */ void printReverse(Node* head) { // Base case if (head == NULL) return ; // print the list after head node printReverse(head->next); // After everything else is printed, print head cout << head->data << " " ; } /*UTILITY FUNCTIONS*/ /* Push a node to linked list. Note that this function changes the head */ void push(Node** head_ref, char new_data) { /* allocate node */ Node* new_node = new Node(); /* put in the data */ new_node->data = new_data; /* link the old list off the new node */ new_node->next = (*head_ref); /* move the head to pochar to the new node */ (*head_ref) = new_node; } /* Driver code*/ int main() { // Let us create linked list 1->2->3->4 Node* head = NULL; push(&head, 4); push(&head, 3); push(&head, 2); push(&head, 1); printReverse(head); return 0; } // This code is contributed by rathbhupendra |
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 off the new node */ new_node->next = (*head_ref); /* move the head to pochar to the new node */ (*head_ref) = new_node; } /* Driver program to test above function*/ int main() { // Let us 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; } |
Java
// Java program to print reverse of a linked list class LinkedList { Node head; // head of list /* Linked list Node*/ class Node { int data; Node next; Node( int d) {data = d; next = null ; } } /* Function to print reverse of linked list */ void printReverse(Node head) { if (head == null ) return ; // print list of head node printReverse(head.next); // After everything else is printed System.out.print(head.data+ " " ); } /* Utility Functions */ /* Inserts a new Node at front of the list. */ public void push( int new_data) { /* 1 & 2: Allocate the Node & Put in the data*/ Node new_node = new Node(new_data); /* 3. Make next of new Node as head */ new_node.next = head; /* 4. Move the head to point to new Node */ head = new_node; } /*Driver function to test the above methods*/ public static void main(String args[]) { // Let us create linked list 1->2->3->4 LinkedList llist = new LinkedList(); llist.push( 4 ); llist.push( 3 ); llist.push( 2 ); llist.push( 1 ); llist.printReverse(llist.head); } } /* This code is contributed by Rajat Mishra */ |
Python3
# Python3 program to print reverse # of a linked list # Node class class Node: # Constructor to initialize # the node object def __init__( self , data): self .data = data self . next = None class LinkedList: # Function to initialize head def __init__( self ): self .head = None # Recursive function to print # linked list in reverse order def printrev( self , temp): if temp: self .printrev(temp. next ) print (temp.data, end = ' ' ) else : return # Function to insert a new node # at the beginning def push( self , new_data): new_node = Node(new_data) new_node. next = self .head self .head = new_node # Driver code llist = LinkedList() llist.push( 4 ) llist.push( 3 ) llist.push( 2 ) llist.push( 1 ) llist.printrev(llist.head) # This code is contributed by Vinay Kumar(vinaykumar71) |
C#
// C# program to print reverse of a linked list using System; public class LinkedList { Node head; // head of list /* Linked list Node*/ class Node { public int data; public Node next; public Node( int d) { data = d; next = null ; } } /* Function to print reverse of linked list */ void printReverse(Node head) { if (head == null ) return ; // print list of head node printReverse(head.next); // After everything else is printed Console.Write(head.data + " " ); } /* Utility Functions */ /* Inserts a new Node at front of the list. */ public void push( int new_data) { /* 1 & 2: Allocate the Node & Put in the data*/ Node new_node = new Node(new_data); /* 3. Make next of new Node as head */ new_node.next = head; /* 4. Move the head to point to new Node */ head = new_node; } /*Driver function to test the above methods*/ public static void Main(String []args) { // Let us create linked list 1->2->3->4 LinkedList llist = new LinkedList(); llist.push(4); llist.push(3); llist.push(2); llist.push(1); llist.printReverse(llist.head); } } // This code has been contributed by Rajput-Ji |
Output:
4 3 2 1
Time Complexity: O(n)
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.