using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Singleton singleton =  Singleton.GetInstance();

        Console.WriteLine("All letters");

        singleton.GetLetters().ForEach(x => Console.Write(x));

        List<string> player1 = singleton.GetTiles(7);

        Console.WriteLine("Player1's letters");

        player1.ForEach(x => Console.Write(x));

        Console.WriteLine("\nSingleton instantance " + singleton.GetHashCode());

        Singleton singleton2 = Singleton.GetInstance();

        List<string> player2 = singleton2.GetTiles(8);

        Console.WriteLine("Player2's letters");

        player2.ForEach(x => Console.Write(x));

        Console.WriteLine("Singleton instantance" + singleton2.GetHashCode());

    }

}

​

public class Singleton

{

   private static Singleton firstInstance = null;

   private Singleton(){}

    static string[] scrabbleLetters = {"a", "a", "a", "a", "a", "a", "a", "a", "a", "b", "b", "c", "c", "d", "d", "d", "d", "e", "e", "e", "e", "e", "e", "e", "e", "e", "e", "e", "e", 

                               "f", "f", "g", "g", "g", "h", "h", "i", "i", "i", "i", "i", "i", "i", "i", "i", "j", "k", "l", "l", "l", "l", "m", "m", "n", "n", "n", "n", "n", "n",

                               "o", "o", "o", "o", "o", "o", "o", "o", "p", "p", "q", "r", "r", "r", "r", "r", "r", "s", "s", "s", "s", "t", "t", "t", "t", "t", "t", 

                               "u", "u", "u", "u", "v", "v", "w", "w", "x", "y", "y", "z"}; 

    private List<string> letterList = new List<string>(scrabbleLetters);

    public static Singleton GetInstance()

    {

        if(firstInstance == null)

            firstInstance = new Singleton();

        return firstInstance;

    }

    public List<string> GetLetters()

    {

        return firstInstance.letterList;

    }

    public List<string> GetTiles(int howManyTiles)

    {

        List<string> letters = new List<string>();

        for(int i = 0; i < howManyTiles; i++)

        {

            letters.Add(firstInstance.letterList.First());

            firstInstance.letterList.RemoveAt(0);

        }

        return letters;

    }

}