Problem Statement

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.

Let's start with the solution:

func msum35 n .
   for i = 1 to n
      if i mod 3 = 0 or i mod 5 = 0
         sum += i
      .
   .
   return sum
.
print msum35 999