Project Euler Problem 1

For Problem 1, we are asked to "Find the sum of all the multiples of 3 or 5 below 1000." To do this, I created a helper function called Integers(), contained in a class called NumberGenerator. This method uses the "yield return" operator to return integers, starting at 1. It is as follows:

public static IEnumerable Integers()
{
long currentValue = 1;
while (true)
{
yield return currentValue++;
}
}

Then, the main method of the Problem001 class uses the "Integers()" method along with LINQ expressions, as follows:

public class Problem001
{
public void Run()
{
var expression = new Func(
p => p.IsMultipleOf(3) || p.IsMultipleOf(5));
Console.WriteLine("Sum using Linq expression: {0}", NumberGenerator.Integers().Take(999).Where(expression).Sum());
}
}

I also added an extension method to the long type called "IsMultipleOf()", which is implemented as follows:

public static bool IsMultipleOf(this long x, int m)
{
return (x % m == 0);
}

This was my first real exposure to LINQ and enumerators, and I was pretty impressed with it. Note that this code was very similar to that of Steve Smith, as I noted in my previous post that he was the inspiration for me getting into Project Euler in the first place.