Write a Program to swap nodes in a singly linked list without swapping data

Solution:

using System;

namespace LinkedListOpearation
{
    class Program
    {
        public static void Main()
        {
            var linkedList = new LinkedList();
            linkedList.Add(6);
            linkedList.Add(1);
            linkedList.Add(5);
            linkedList.Add(1);
            linkedList.Add(3);
            linkedList.Add(9);
            Console.WriteLine("Sorted Linked List:");
            linkedList.Print(linkedList.Head);
            linkedList.Swap(5, 9);
            Console.WriteLine("After swap Linked List:");
            linkedList.Print(linkedList.Head);
            Console.ReadLine();
        }   
    }

    
    public class LinkedList
    {
        public Node Head;
        public int Size;
        public void Add(int data)
        {
            var node = new Node(data) {Next = Head};
            Head = node;
            Size++;
        }

        public void Swap(int data1, int data2)
        {
            Node prevNode1 = null;
            Node prevNode2 = null;
            var node1 = Head;
            var node2 = Head;

            if (Head == null)
                return;

            if (data1 == data2)
                return;

            while (node1 != null && node1.Data != data1)
            {
                prevNode1 = node1;
                node1 = node1.Next;
            }

            while (node2 != null && node2.Data != data2)
            {
                prevNode2 = node2;
                node2 = node2.Next;
            }

            if (node1 == null || node2 == null) return;

            if (prevNode1 != null)
                prevNode1.Next = node2;
            else
                Head = node2;
 
            if (prevNode2 != null)
                prevNode2.Next = node1;
            else
                Head = node1;

            var temp = node1.Next;
            node1.Next = node2.Next;
            node2.Next = temp;
        }

        public void Print(Node head)
        {
            while (head != null)
            {
                Console.WriteLine(head.Data);
                head = head.Next;
            }
        }
    }

    public class Node
    {
        public int Data;
        public Node Next;

        public Node(int data)
        {
            Data = data;
        }
    }
}