static void Main(string[] args)
{
Stopwatch sw = new Stopwatch();
sw.Start();
Factorial f = new Factorial();
long sum = 0;
for (int n = 3; n < UpperBound; n++)
{
long total = 0;
long remainder = n;
while (remainder > 0)
{
long digit = remainder % 10;
total += f.CalculateFactorial(digit);
remainder /= 10;
}
if (total == n)
{
sum += total;
Console.WriteLine("Found {0}", n);
}
}
sw.Stop();
Console.WriteLine("Sum {0} in {1}", sum, sw.ElapsedMilliseconds);
Console.ReadKey();
}
public void CalculateFactorialOf5()
{
Factorial f = new Factorial();
Assert.AreEqual(120, f.CalculateFactorial(5));
}
public void CalculateFactorialOf20()
{
Factorial f = new Factorial();
Assert.AreEqual(2432902008176640000, f.CalculateFactorial(20));
}
public void CalculateFactorialOf3WithCache()
{
Factorial f = new Factorial();
Assert.AreEqual(6, f.CalculateFactorial(3));
Assert.AreEqual(6, f.CalculateFactorial(3));
}
public void CalculateFactorialOf1()
{
Factorial f = new Factorial();
Assert.AreEqual(1, f.CalculateFactorial(1));
}