Das Blinkenlights

ID: dasblinkenlights

Difficulty: 1.7

CPU Time: 1 second

Memory: 1024 MB

Solution

It seems obvious to simply multiple p and q and see if it's less than s, and that will work for some, but not all, cases. Consider p = 5, q = 10, s = 15; this method would say that the soonest match is at 50, but they actually match at 10. The easiest approach is a nested set of loops, outer loop doing all multiples of p within s, and the inner loop being all multiples of q within s, and if these match, the two have flashed at the same time.