using System;
using System.Collections.Generic;
using System.IO;


namespace ConsoleApplication
{
    class Program
    {


        static void Main(string[] args)
        {
            Random rnd = new Random(123);

            LinkedList<int> list = new LinkedList<int>();
            for (int i = 0; i < 25; i++)
            {
                list.AddLast(rnd.Next(0,5));
            }
//Берем итератор
            var iter = list.GetEnumerator();
            Console.WriteLine("До:");
            foreach (var i in list)
            {
                Console.WriteLine(i);
            }
            Console.WriteLine();
            var el = list.First;

            while (iter.MoveNext())
            {
                int prev = -9999;
                int next = -99;
                if (el.Previous != null)
                {
                   
                  
                    prev = el.Previous.Value;
                }
                if (el.Next != null)
                {
                    next = el.Next.Value;
                }

                if (el.Value == prev || prev == next || el.Value == next)
                {
                    Console.WriteLine("DELETE: Prev:{0} ,Curr:{1}, Next:{2}", prev, el.Value, next);
                    //Удаление элемента
                    list.Remove(el);
                    //Получение итератора нового списка
                    iter = list.GetEnumerator();
                    el = list.First;
                }
                
                if (list.Count > 0 && el.Next != null)
                {
                    el = el.Next;
                }
            }
            Console.WriteLine();
            Console.WriteLine("После:");

            foreach (var i in list)
            {
                Console.WriteLine(i);
            }
            Console.ReadKey();
        }
    }
}