Task

The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.

Show output for n = 1000.

This is is the same as Project Euler problem 1.

Extra credit: do this efficiently for n = 1e20 or higher.




iex(1)> Enum.filter(0..1000-1, fn x -> rem(x,3)==0 or rem(x,5)==0 end) |> Enum.sum
233168