using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        GetWordsFrequencyCount("My bike and my book");

        GetWordsLenthFrequencyCount("My bike and my book");

    }

​

    private static void GetWordsLenthFrequencyCount(string sentence)

    {

        var dictionary = new Dictionary<int, int>();

        string[] words = sentence.ToLower().Split(' ');

        foreach (var word in words)

        {

            if (!dictionary.ContainsKey(word.Length))

            {

                dictionary.Add(word.Length, 1);

            }

            else

            {

                dictionary[word.Length]++;

            }

        }

​

        foreach (var key in dictionary.Keys)

        {

            Console.WriteLine(key + ": " + dictionary[key]);

        }

​

        Console.WriteLine();

    }

​

    private static void GetWordsFrequencyCount(string sentence)

    {

        var dictionary = new Dictionary<string, int>();

        string[] words = sentence.ToLower().Split(' ');

        foreach (var word in words)

        {

            if (!dictionary.ContainsKey(word))

            {

                dictionary.Add(word, 1);

            }

            else

            {

                dictionary[word]++;

            }

        }

​

        foreach (var key in dictionary.Keys)

        {

            Console.WriteLine(key + ": " + dictionary[key]);

        }

​

        Console.WriteLine();

    }

} 

​