Word count practice - mock interview

WordCountPractice_MockInterview.cs

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions; 

class Solution
{
    public static string[,] WordCountEngine(string document)
    {
        if(document == null || document.Length == 0)
          return new string[0,0]; 
      
        var length = document.Length; 
      
        var lowerOne = document.ToLower(); 
        var removeExtra = lowerOne.Replace('\'','\0');
      
        var split = Regex.Split(removeExtra, "[ ,.!]+"); 
      
        var dict = storeToDict(split); 
        
        // LINQ 
        var bucketsorted = applyBucketSort(dict); 
      
        var valueMax = bucketsorted.Length;
      
        for(int i = 0; i < valueMax; i++)
        {
          var number = valueMax - 1 - i;
          var current = bucketsorted[number]; 
          if(current.Count == 0)
            continue; 
          
          foreach(var item in current)
          {
            Console.WriteLine(item +" and value is " + number);
          }
        }
      
        return new string[0,0];
                                           
    }
  
    private static List<string>[] applyBucketSort(Dictionary<string, int> dict)
    {
      int maxValue = 0; 
      foreach(var pair in dict)
      {
        var number = pair.Value;
        maxValue = number > maxValue? number : maxValue; 
      }
      
      var sorted = new List<string>[maxValue + 1];
      
      for(int i = 0; i < maxValue + 1; i++)
          sorted[i] = new List<string>(); 
      
      foreach(var pair in dict)
      {
        var key = pair.Key; 
        var number = pair.Value; 
        
        sorted[number].Add(key); 
      }
      
      return sorted; 
    }
  
    private static Dictionary<string, int> storeToDict(string[] split)
    {
      var length = split.Length; 
      var dict = new  Dictionary<string, int>(); 
      
      for(int i = 0; i < length; i++)
      {
        var current = split[i]; 
        if(!dict.ContainsKey(current))
          dict.Add(current, 1); 
        else 
          dict[current]++; 
      }
      
      return dict; 
    }

    static void Main(string[] args)
    {
        Console.WriteLine(WordCountEngine("a bus bus cat cat Cat")); 
    }
}

/*
"Practice makes perfect, you'll get perfecT by practice. just practice! just just just!!"
  
 [["just","4"],["practice","3"],["perfect","2"],["makes","1"],["youll","1"],["get","1"],["by","1"]]
 
 
 */