using System;

public class Program

{

    public static void Main()

    {

        var node3 = new Node<int>{element = 3};

        var node2 = new Node<int>{element = 2, next = node3};

        var node1 = new Node<int>{element = 1 , next = node2};

        Node<int> node = node1;

        Node<int> tempNext = null;

        Node<int> reverseNext = null;

        //Console.WriteLine(node.element);

        // start with first node +

        // end when node is null +

        // set new next for all nodes

        // first next is null

        // next next is current node

        // next current node is node.next

        // last next is node before last node

        // 

        while (node != null){

            reverseNext = tempNext;

            tempNext = node;

            Console.WriteLine(node.element);

            node = node.next;

            tempNext.next = reverseNext;        

    }

            Console.WriteLine();

        node = node3;

        while (node != null){

            Console.WriteLine(node.element);

            node = node.next;   

    }

    }

}

​

public class Node<T>

{   

    public T element;

    public Node<T> next;

}