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

namespace Flyweight
{
    /// <summary>

    /// MainApp startup class for Structural 

    /// Flyweight Design Pattern.

    /// </summary>

    class MainApp
    {
        /// <summary>

        /// Entry point into console application.

        /// </summary>

        static void Main()
        {
            // Arbitrary extrinsic state

            int extrinsicstate = 22;

            FlyweightFactory factory = new FlyweightFactory();

            // Work with different flyweight instances

            Flyweight fx = factory.GetFlyweight("X");
            fx.Operation(--extrinsicstate);

            Flyweight fy = factory.GetFlyweight("Y");
            fy.Operation(--extrinsicstate);

            Flyweight fz = factory.GetFlyweight("Z");
            fz.Operation(--extrinsicstate);

            UnsharedConcreteFlyweight fu = new

              UnsharedConcreteFlyweight();

            fu.Operation(--extrinsicstate);

            // Wait for user

            Console.ReadKey();
        }
    }

    /// <summary>

    /// The 'FlyweightFactory' class

    /// </summary>

    class FlyweightFactory
    {
        private Hashtable flyweights = new Hashtable();

        // Constructor

        public FlyweightFactory()
        {
            flyweights.Add("X", new ConcreteFlyweight());
            flyweights.Add("Y", new ConcreteFlyweight());
            flyweights.Add("Z", new ConcreteFlyweight());
        }

        public Flyweight GetFlyweight(string key)
        {
            return ((Flyweight)flyweights[key]);
        }
    }

    /// <summary>

    /// The 'Flyweight' abstract class

    /// </summary>

    abstract class Flyweight
    {
        public abstract void Operation(int extrinsicstate);
    }

    /// <summary>

    /// The 'ConcreteFlyweight' class

    /// </summary>

    class ConcreteFlyweight : Flyweight
    {
        public override void Operation(int extrinsicstate)
        {
            Console.WriteLine("ConcreteFlyweight: " + extrinsicstate);
        }
    }

    /// <summary>

    /// The 'UnsharedConcreteFlyweight' class

    /// </summary>

    class UnsharedConcreteFlyweight : Flyweight
    {
        public override void Operation(int extrinsicstate)
        {
            Console.WriteLine("UnsharedConcreteFlyweight: " +
              extrinsicstate);
        }
    }
}