Solving Fibonacci Series with Dynamic Programming in C#

FibonacciSeriesSolution.cs

using System;
using System.Diagnostics;

// Solving Fibonacci series with Dynamic 
// Programming algorithms using C# 
public class Program
{
	public static void Main()
	{
		Console.WriteLine("Solving Fibonacci Series with Dynamic Programming in C#");
		Console.WriteLine("=======================================================");
		Console.WriteLine("==================BY==UDARA ALWIS======================");
		Console.WriteLine("=======================================================");
		Console.WriteLine("");
		
		Console.WriteLine("Recursive method");
		Stopwatch stopwatch = Stopwatch.StartNew();
		
		// Recursive
		for (int i = 0; i < 30; i++)
		{
			Console.Write(GetFibValueOf_Recursive(i + 1).ToString() + ",");
		}
		
		stopwatch.Stop();
		
		Console.WriteLine("\nTime elapsed: {0}", stopwatch.ElapsedTicks);
		Console.WriteLine();

		Console.WriteLine("Memoize method");
		stopwatch = Stopwatch.StartNew();
				
		// Memoize
		for (int i = 0; i < 30; i++)
		{
			int? [] memoList = new int? [i + 1];
			Console.Write(GetFibValueOf_Memoize(i + 1, memoList).ToString() + ",");
		}
		
		stopwatch.Stop();
		
		Console.WriteLine("\nTime elapsed: {0}", stopwatch.ElapsedTicks);	
		Console.WriteLine();	
		
		Console.WriteLine("Bottom Up method");
		stopwatch = Stopwatch.StartNew();
				
		// Bottom Up
		for (int i = 0; i < 30; i++)
		{
			Console.Write(GetFibValueOf_BottomUp(i + 1).ToString() + ",");
		}
		
		stopwatch.Stop();
		
		Console.WriteLine("\nTime elapsed: {0}", stopwatch.ElapsedTicks);	
		Console.WriteLine();	
	}

	private static int GetFibValueOf_Recursive(int position)
	{
		if (position == 1 || position == 2)
			return 1;
		return GetFibValueOf_Recursive(position - 1) + GetFibValueOf_Recursive(position - 2);
	}

	private static int? GetFibValueOf_Memoize(int position, int? [] memoList)
	{
		if (memoList[position - 1] != null)
		{
			return memoList[position - 1];
		}

		int? result = 0;
		if (position == 1 || position == 2)
			result = memoList[position - 1] = 1;
		else
		{
			result = memoList[position - 1] = GetFibValueOf_Memoize(position - 1, memoList) + GetFibValueOf_Memoize(position - 2, memoList);
		}

		return result;
	}
	
	private static int? GetFibValueOf_BottomUp(int position)
	{
		if(position == 1 || position == 2)
			return 1;
		else
		{
			int[] fibArray = new int[position];
			fibArray[0] = 1;
			fibArray[1] = 1;
			
			for(int i = 2; i < position; i++)
			{
				fibArray[i] = (fibArray[i - 1]) + (fibArray[i - 2]);
			}
			
			return fibArray[position - 1];
		}
	}
}


// RESULTS:
// Solving Fibonachi Series with Dynamic Programming in C#
// =======================================================
// ==================BY==UDARA ALWIS======================
// =======================================================
//
// Recursive method
// 1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025,121393,196418,317811,514229,832040,
// Time elapsed: 271522
//
// Memoize method
// 1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025,121393,196418,317811,514229,832040,
// Time elapsed: 3608
//
// Bottom Up method
// 1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025,121393,196418,317811,514229,832040,
// Time elapsed: 2318