Word count engine - write my own C# code, and play with LINQ GroupBy and OrderByDescending clause etc.

WordCountEngine_WriteMyCode_mockInterview.cs

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

class Solution
{
    public static string[,] WordCountEngine(string document)
    {
        if(document == null || document.Length == 0)
        {
          return new string[0,0]; 
        }
      
        var preprocessed = document.ToLower().Replace('\'', '\0'); // remove ' to empty space
           
        var splitted = preprocessed.Split(", !".ToCharArray()); 
      
        // https://stackoverflow.com/questions/7325278/group-by-in-linq
        var map = splitted.GroupBy(x => x).OrderByDescending(g => g.Count()); 
      
        var countedWord = new List<string>(); 
        var countValue  = new List<string>(); 
      
        foreach(var item  in map)
        {
          var previous = ""; 
         
          int index = 0; 
          
          foreach(string element in item)   "a a a b b c"
          {
            var isNew = previous.CompareTo(element) != 0; 
            if(isNew)
            {
              if(previous != "")
              {
                countValue.Add(index.ToString());     
                index = 0; 
              }              
              
              countedWord.Add(element);                            
            }
            
            index++;            
            
            previous = element; 
          }
        }
      
        Console.WriteLine(countedWord.Count); 
        Console.WriteLine(countValue.Count);
      
        for(int i = 0; i < Math.Min(countedWord.Count,countValue.Count) ; i++)
        {
          Console.WriteLine(countedWord[i] +"  "+ countValue[i]); 
        }
          
        return new string[0,0];
                                                 
    }

    static void Main(string[] args)
    {
        WordCountEngine("a b c a a b c");
    }
}

/*

string[] words = string.Split(" .!")


lowercase -> Practice -> practice
bucket sort 

dictionary<string, int> practice 3 

sort by total value -> 
value -> max value 
value-> OrderByValue -> 

 value = 3   value 2     value 1
bucket        perfect     by
                          get
                          just
descending -> biggest value first -> go to small value                           

*/