linked list reversal recursive, C#

linked list reversal recursive

//Title of this code
//Rextester.Program.Main is the entry point for your code. Don't change it.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Node head = null;
            LinkedList.Append(ref head, 25);
            LinkedList.Append(ref head, 5);
            LinkedList.Append(ref head, 18);
            LinkedList.Append(ref head, 7);
            
            Console.WriteLine("Linked list:");
            LinkedList.Print(head);
            
            LinkedList.Reverse(ref head);
            
            Console.WriteLine();
            Console.WriteLine("Reversed Linked list:");
            LinkedList.Print(head);
            
            Console.WriteLine();
            //LinkedList.PrintRecursive(head);
            
            Console.WriteLine("Reverse of Reversed Linked list:");

LinkedList.ReverseUsingRecursion(head);
            head = LinkedList.newHead;
            LinkedList.PrintRecursive(head);
            
        }
        
        public static class LinkedList
        {

public static void Append(ref Node head, int data)
            {
                if (head != null)
                {
                    Node current = head;
                    while(current.Next != null)
                    {
                        current = current.Next;
                    }

current.Next = new Node();
                    current.Next.Data = data;
                }
                else
                {
                    head = new Node();
                    head.Data = data;
                }
            }
            
            public static void Print(Node head)
            {
                if (head == null) return;
                
                Node current = head;
                do
                {
                    Console.Write("{0} ", current.Data);
                    current = current.Next;
                } while(current != null);
            }
            
            public static void PrintRecursive(Node head)
            {
                if (head == null)
                {
                    Console.WriteLine();
                    return;
                }
                
                Console.Write("{0} ", head.Data);
                PrintRecursive(head.Next);
            }
            
            public static void Reverse(ref Node head)
            {
                if (head == null) return;
                
                Node prev = null, current = head, next = null;
                
                while( current.Next != null )
                {
                    next = current.Next;
                    current.Next = prev;
                    prev = current;
                    current = next;
                }
                
                current.Next = prev;
                head = current;
            }
            
            public static Node newHead;
            
            public static void ReverseUsingRecursion(Node head)
            {
                if (head == null) return;
                
                if (head.Next == null)
                {
                    newHead = head;
                    return;
                }
                
                ReverseUsingRecursion(head.Next);
                head.Next.Next = head;
                head.Next = null;
                
            }
        }
        
        public class Node
        {
            public int Data = 0;
            public Node Next = null;
        }
    }
}


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