View difference between Paste ID: DMXDcUUQ and 2Uz8nVuU

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 
 namespace ConsoleApplication1
 {
     class Program
     {
         static void Main(string[] args)
         {
             link<int> a = new link<int> { };
             a.addFirst(new node<int>(1));
             a.add(1);
             a.add(2);
             a.add(3);
             a.add(4);
             a.add(1);
             a.print();
             a.removeAfter(????);
             a.print();
         }
     }
     class node<T>
     {
         public T data;
         public node<T> next;
         public node(T data)
         {
             this.data = data;
         }
     }
     class link<T>
     {
         node<T> firstNode;
         node<T> lastnode;
         public void add(T Node)
         {
                 node<T> newnode = new node<T>(Node);
                 newnode.next = this.lastnode.next;
                 lastnode.next = newnode;
 
         }
         public void addFirst( node<T> newNode)
         {
             newNode.next = firstNode;
-            firstNode =lastnode= newNode;
+            firstNode = newNode;
         }
         public void removeAfter(node<T> node)
         {
             node.next = node.next.next;
         }
         public void removeBeggining(link<T> link)
         {
             if (link.firstNode.next != null)
             {
                 link.firstNode = link.firstNode.next;
             }
         }
         public void print()
         {
             node<T> node = firstNode;
             while (node.next != null)
             {
                 Console.WriteLine(node.data);
                 if (node.next != null)
                 {
                     node = node.next;
                 }
             }
         }
     }
 }