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.




proc sum35(n: int): int =
  for x in 0 ..< n:
    if x mod 3 == 0 or x mod 5 == 0:
      result += x
 
echo sum35(1000)