[pbiggar]

You're missing the point, and this is how people end up at these "puzzlers". The point of fizzbuzz or the simple questions is to weed out people who can't code at all. If you transform it like you do above, then you're testing something else: how well people know low-level tricks like swapping variables using xor.

Those tricks might be valuable in your workplace, and may make excellent interview questions for you, but they are a very very different type of question than fizzbuzz, at least in purpose, even though they may look superficially similar. In a fizzbuzz type question, you are not looking for brilliance, you are looking to just weed out the people who can't.

[doktrin]

Exactly. This is precisely the problem. It's not that any particular question is a "bad" choice, per se, it's that interviewers can fail to realize what they are actually testing for.