Reverse a linked list Java

PROGRAM TO REVERSE A LINKED LIST

class LinkedList {

 

    static Node head;

 

    static class Node {

 

        int data;

        Node next;

 

        Node(int d)

        {

            data = d;

            next = null;

        }

    }

 

    // A simple and tail recursive function to reverse

    // a linked list.  prev is passed as NULL initially.

    Node reverseUtil(Node curr, Node prev)

    {

        /*If head is initially null OR list is empty*/

        if (head == null)

            return head;

        /* If last node mark it head*/

        if (curr.next == null) {

            head = curr;

 

            /* Update next to prev node */

            curr.next = prev;

 

            return head;

        }

 

        /* Save curr->next node for recursive call */

        Node next1 = curr.next;

 

        /* and update next ..*/

        curr.next = prev;

 

        reverseUtil(next1, curr);

        return head;

    }

 

    // prints content of double linked list

    void printList(Node node)

    {

        while (node != null) {

            System.out.print(node.data + " ");

            node = node.next;

        }

    }

 

    // Driver Code

    public static void main(String[] args)

    {

        LinkedList list = new LinkedList();

        list.head = new Node(1);

        list.head.next = new Node(2);

        list.head.next.next = new Node(3);

        list.head.next.next.next = new Node(4);

        list.head.next.next.next.next = new Node(5);

        list.head.next.next.next.next.next = new Node(6);

        list.head.next.next.next.next.next.next

            = new Node(7);

        list.head.next.next.next.next.next.next.next

            = new Node(8);

 

        System.out.println("Original Linked list ");

        list.printList(head);

        Node res = list.reverseUtil(head, null);

        System.out.println("");

        System.out.println("");

        System.out.println("Reversed linked list ");

        list.printList(res);

    }

}




OUTPUT

Given linked list
1 2 3 4 5 6 7 8 

Reversed linked list
8 7 6 5 4 3 2 1

CREDITS: https://www.geeksforgeeks.org/reverse-a-linked-list/