using System;

using System.Collections.Generic;

using System.Collections;

​

public class Program

{

    public static void Main()

    {

        int[,] array = { { 1, 2, 3 ,1,1,5}, { 543, 541, 543,43,43,99 } };

        Dictionary<int, List<int>> sorted = new Dictionary<int, List<int>>();

        for(int i = 0; i < array.GetLength(0); i++)

        {

            for(int j = 0;j < array.GetLength(1) ; j++)

            {

                if(!sorted.ContainsKey(array[i,j]))

                    sorted.Add(array[i,j],new List<int>());

                //  sorted

                //array[i][j]

            }

        }

    }

}