using System;

using System.Collections.Generic;

​

public class llNode

{

    public llNode(int v, llNode n = null)

    {

        next = n;

        val = v;

    }

​

    public llNode next;

​

    public int val;

​

    public void printList()

    {

        Console.WriteLine(val);

        if(next != null)

        {

            next.printList();               

        }

    }

    // 1 -> 2 -> 3 -> 4 -> null

    static public void reverseList(llNode n)

    {

        llNode current = n.next;

        llNode previous = n;

        n.next = null;

        while(current != null)

        {

            llNode next = current.next;

            current.next = previous;

            previous = current;

            current = next;

        }

    }

}

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        llNode n10 = new llNode(43);

        llNode n9 = new llNode(19, n10);

        llNode n8 = new llNode(100, n9);

        llNode n7 = new llNode(994, n8);

        llNode n6 = new llNode(77, n7);

        llNode n5 = new llNode(55, n6);

        llNode n4 = new llNode(65, n5);

        llNode n3 = new llNode(4, n4);

        llNode n2 = new llNode(2, n3);

        llNode n1 = new llNode(78, n2);

        n1.printList();

        llNode.reverseList(n1);

        Console.WriteLine();

        n10.printList();

    }

}