reverse a linked list in a recursive function c#

Question

I'm having problems trying to write a reverse recursive method for a LinkedList class I created in C#. The LinkedList has 2 pointers in it one for the head and the other for the tail:

public class Node
{
    public object data;
    public Node next;
    public Node(object Data)
    {
        this.data = Data;
    }
}

public class LinkedList
{
    Node head;
    Node tail;
    public void Add(Node n)
    {
        if (head == null)
        {
            head = n;
            tail = head;
        }
        else
        {
            tail.next = n;
            tail = tail.next;
        }
    }

Now, the recursive reverse function goes like this:

    public void reverse_recursive()
    {
        Node temp_head = head;
        if (temp_head == tail)
        {

            return;
        }

        while (temp_head != null)
        {
            if (temp_head.next == tail)
            {
                tail.next = temp_head;
                tail = temp_head;
                reverse_recursive();
            }
            temp_head = temp_head.next;
        }
    }

I'm having 2 troubles with it: first, a logic problem, I know that head doesn't point to the first node after the reverse. The second problem is that i probably do something wrong with the null pointer so the program crashes.

I also give you the main program:

class Program
{
    static void Main(string[] args)
    {
        LinkedList L = new LinkedList();
        L.Add(new Node("first"));
        L.Add(new Node("second"));
        L.Add(new Node("third"));
        L.Add(new Node("forth"));
        L.PrintNodes();
        L.reverse_recursive();
        L.PrintNodes();
        Console.ReadLine();
    }
}

Thank you for helping!!

Answer 1

public void Reverse()
{
    this.Reverse(this.head);
}

private void Reverse(Node node)
{
    if (node != null && node.next != null)
    {
        // Create temporary references to the nodes, 
        // because we will be overwriting the lists references.
        Node next = node.next;
        Node afterNext = node.next.next;
        Node currentHead = this.head;

        // Set the head to whatever node is next from the current node.
        this.head = next;

        // Reset the next node for the new head to be the previous head.
        this.head.next = currentHead;

        // Set the current nodes next node to be the previous next nodes next node :)
        node.next = afterNext;

        // Keep on trucking.
        this.Reverse(node);
    }
    else
    {
        this.tail = node;
    }
}