use sortedset

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

namespace AnotherLog4
{
    class Program
    {


        static void Main(string[] args)
        {
            List<byte[]> list = new List<byte[]>();
            Random rd = new Random(); 
            for (int i = 0; i < 15; i++)
            {
                list.Add(new Byte[] { (Byte)rd.Next(0,200) });
                list.Add(new Byte[] { (Byte)rd.Next(0, 200) });
            }

            var compare = new ByteComparetor();
            SortedSet<Byte[]> hashset = new SortedSet<Byte[]>(list,compare);        // use binary-tree structure

            Console.WriteLine("My method");
            var compare2 = new ByteComparetor();
            var result = compare2.GetCompareResult(list);
            foreach (var item in result)
            {
                Console.WriteLine(item[0]);
            }

            Console.WriteLine("LingLing method");
            foreach (var item in hashset)
            {
                Console.WriteLine(item[0]);
                // Console.WriteLine(item);
            }
            Console.WriteLine("Total Compare time is :" + compare.count);
            Console.WriteLine("Total sencnd Compare time is :" + compare2.count);
            Console.WriteLine("Total count  :" + list.Count);
            Console.WriteLine("My Filter count  :" + (list.Count - result.Count()));
            Console.WriteLine("Filter count  :" + (list.Count - hashset.Count));
            Console.Read();
        }
    }

    public class ByteComparetor : IComparer<byte[]>
    {
        public  int count = 0;

        public int Compare(byte[] a1, byte[] a2)
        {
            count++;
            int len = a1.Length < a2.Length ? a1.Length : a2.Length;    // get the shorter length
            int res = 0;

            for (int i = 0; i < len; i++)
            {
                if ((res = (a1[i] - a2[i])) != 0) // if not equal, return the result;
                    return res;
            }

            if (a1.Length != a2.Length)     // like:"abc" "abc1", we think the longger one is bigger than the shorter.
            {
                return (a1.Length - a2.Length);
            }
            else                                        // when compared strings is totally same.
            {
                return 0;
            }
        }

        bool ByteArrayCompare(byte[] a1, byte[] a2)
        {
            count++;
            if (a1.Length != a2.Length)
                return false;

            for (int i = 0; i < a1.Length; i++)
                if (a1[i] != a2[i])
                    return false;

            return true;
        }

        public IEnumerable<byte[]> GetCompareResult(List<Byte[]> source)
        {
            List<Byte[]> result = new List<Byte[]>();
            Dictionary<int, List<int>> dic = new Dictionary<int, List<int>>() { };
            List<int> sameList = new List<int>();
            for (int i = 0; i < source.Count; i++)
            {
                if (sameList.Contains(i))
                    continue;
                for (int j = i + 1; j < source.Count; j++)
                {
                    if (sameList.Contains(j))
                        continue;
                    bool isSame = ByteArrayCompare(source[i], source[j]);
                    if (isSame)
                    {
                        if (!dic.ContainsKey(i))
                        {
                            dic.Add(i, new List<int>() { j });
                        }
                        else
                        {
                            dic[i].Add(j);
                        }

                        sameList.Add(j);
                    }
                }

                //for data which do not have same
                if (!dic.ContainsKey(i))
                {
                    result.Add(source[i]);
                }
            }

            //For data which 
            foreach (var key in dic.Keys)
            {
                result.Add(source[key]);
            }

            return result;
        }
    }
}