using System;

public class Program

{

    public static void Main()

    {

        int k = 3;

        Node<int> node = FormLinkedListNodes();

        Print(node, "Original Node is:  ");

        Console.WriteLine("");

        Console.WriteLine("K value is:  " + k);

        Console.WriteLine("");

        Console.WriteLine("");

        Node<int> res = NthNodeFromLast(node, k);

        Console.Write("Kth node from Last is:  " + res.data);

    }

    private static void Print(Node<int> node, string str)

    {

     Console.Write(str);

     while(node != null)

     {

      Console.Write(node.data + " --> ");

      node = node.next;

     }

     Console.Write("null");

    }

    private static Node<int> FormLinkedListNodes()

    {

        Node<int> node = new Node<int>();

        node.data = 6;

        node.next = new Node<int>();

        node.next.data = 5;

        node.next.next = new Node<int>();

        node.next.next.data = 3;

        node.next.next.next = new Node<int>();

        node.next.next.next.data = 1;

        node.next.next.next.next = new Node<int>();

        node.next.next.next.next.data = 8;

        node.next.next.next.next.next = new Node<int>();

        node.next.next.next.next.next.data = 7;

        node.next.next.next.next.next.next = new Node<int>();

        node.next.next.next.next.next.next.data = 2;

        node.next.next.next.next.next.next.next = new Node<int>();

        node.next.next.next.next.next.next.next.data = 4;

        node.next.next.next.next.next.next.next.next = null;

        return node;

    }

    private static Node<int> NthNodeFromLast(Node<int> node, int n)

    {

        if (node == null)

            return null;

​

        if (n < 1)

            return null;

​

        Node<int> fast = node;

        Node<int> slow = node;

        int count = 0;

​

        while (fast != null)

        {

            if (count >= n)

            {

                slow = slow.next;

            }

            fast = fast.next;

            ++count;

        }

​

        slow.next = null;

        return slow;

    }

}

​

​

public class Node<T>

{

   public Node<T> next;

   public T data;

   public Node()

   {

   }

​

   public Node(T obj)

   {

    data = obj;

   }

}