Finding how many combinations of change can be produced based on a total amount and list of denominations in C#.

countChange.cs

namespace CountChange
{
  class Program
  {
    static int CountChange(int money, int[] coins)
    {
      if (money == 0) return 1;
      else if (money < 0 || coins.Length == 0) return 0;
      else return CountChange(money - coins.First(), coins) + CountChange(money, coins.Skip(1).ToArray());
    }
  
    static void Main(string[] args)
    {
      int money = 300;
      int[] coins = {5, 10, 20, 50, 100, 200, 500};
      Console.WriteLine("CountChange: "+CountChange(money, coins));
      Console.ReadKey();
    }
  }
}