using System;

namespace LinkedListApp

{

public class Program

{

    public static void Main()

    {

        LinkedList list = new LinkedList();

        list.append(1);

        list.append(2);

        list.append(3);

        list.append(4);

        list.append(5);

        PrintList(list);

        Node Head = list.ReverseRecursive(list.head,null);

        PrintList(list);

    }   

    public static void PrintList(LinkedList list)

    {

        Node current = list.head;

        while(current!=null)

        {

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

            current = current.next;

        }

        Console.WriteLine("NULL");

        Console.WriteLine("count of items in list are " + list.Count);

    }

}

// 1->2->3->4->5

public class Node

{

    public Node next;

    public int data;

    public Node(int data)

    {

        this.data = data;

    }   

}

​

public class LinkedList

{

    public Node head;

    public int Count = 0;

    // 1->2->3->4->5

    public void append(int data)

    {

        if(head == null)

        {

            head = new Node(data);

            Count++;

            return;

        }

        Node current = head;

        while(current.next!=null)

        {

            current = current.next;

        }

        current.next = new Node(data);

        Count++;

    }

    // 1->2->3->4->5

    public void prepend(int data)

    {

        if(head == null)

        {

            head = new Node(data);

            Count++;

            return;

        }

        else

        {

            Node newHead = new Node(data);

            newHead.next = head;

            head = newHead; 

            Count++;

        }       

    }

    // 1->2->3->4->5

    public void deleteWithValue(int data)

    {

        if(head == null) return;        

        if(head.data == data)

        {

            head = head.next;

            Count--;

        }

        Node current = head;

        while(current.next !=null)

        {

            if(current.next.data == data)

            {

                current.next = current.next.next;

                Count--;

                return;

            }

            current = current.next;

        }

    }

    public Node ReverseListIterative ()

    {

        // not implemented

        if(head == null || head.next == null)

            return head;

        else

        {

            Node prev = null;

            Node current = head;

            Node next = null;

            while(current != null)

            {

                next = current.next; // store next in temp;

                current.next = prev; // update next to prev;

                prev = current; // move previous and current  

                current = next;

            }

            head = prev;

            return head;

        }   

    }

    public Node ReverseRecursive (Node current, Node prev)

    {

        //while(current.next!=null)

    //  {           

    //      Node next = current.next;

    //      current.next = prev;

    //      ReverseRecursive(next, current);

    //  }

        if(current.next == null)

        {

            head = current;

            current.next = prev;

            return head;

        }

        Node next = current.next;

        current.next = prev;

        ReverseRecursive(next, current);

        return head;

    }

}

}

​