That's a bit unfair. I agree that Array.sort is the best answer, but array sorting is such a classic interview puzzle that most candidates will expect that that

That's a bit unfair. I agree that Array.sort is the best answer, but array sorting is such a classic interview puzzle that most candidates will expect that that's what you want. So instead of the bonus answer, they'll slog away trying to remember the algorithms that they learnt at uni years ago (or codecademy last month).