Generic Memoization

GenericMemoization.cs

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

namespace CSharp2
{
  class Program
  {

    private static FibCalc fibCalc = new FibCalc();

    static void Main(string[] args)
    {
      Test(1, 1);
      Test(2, 1);
      Test(3, 2);
      Test(9, 34);

      Console.ReadKey();
    }

    public static void Test(int x, int expected)
    {
      int result = fibCalc.Fib(x);
      string correct = (result == expected) ? "OK    " : "ERROR ";
      Console.WriteLine("{0}{1} -> {2}", correct, x, result);
    }


    public class FibCalc
    {
      private readonly Memoizer<int, int> _memoizer;

      public FibCalc()
      {
        _memoizer = new Memoizer<int, int>((x) => { return Fib(x); });
      }

      public int Fib(int x)
      {
        if (x < 2)
          return x;
        else
          return _memoizer.GetValue(x - 1) + _memoizer.GetValue(x - 2);
      }
    }


    public class Memoizer<K, V>
    {
      private Dictionary<K, V> _memoized = new Dictionary<K, V>();
      private Func<K, V> _func;
      public Memoizer(Func<K, V> func)
      {
        _func = func;
      }

      public V GetValue(K key)
      {
        V value;
        if (_memoized.TryGetValue(key, out value))
        {
          return value;
        }
        else
        {
          value = _func(key);
          _memoized.Add(key, value);
          return value;
        }
      }
    }

    
  }
}