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:
Javascript
<script> // Javascript program to print reverse // of a linked list // Head of list var head;
// Linked list Node class Node { constructor(val)
{
this .data = val;
this .next = null ;
}
} // Function to print reverse of // linked list function printReverse(head)
{ if (head == null )
return ;
// Print list of head node
printReverse(head.next);
// After everything else is printed
document.write(head.data + " " );
} // Utility Functions // Inserts a new Node at front of the list. function push(new_data)
{ /* 1 & 2: Allocate the Node &
Put in the data */
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 code // Create linked list 1->2->3->4 push(4); push(3); push(2); push(1); printReverse(head); // This code is contributed by Rajput-Ji </script> |
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!