Let’s not overthink this. Microsoft is using this test as a low-pass filter to get rid of candidates who would: - not find any answer in a few minutes - find

Let’s not overthink this. Microsoft is using this test as a low-pass filter to get rid of candidates who would: - not find any answer in a few minutes - find a wrong answer and argue about it in an obnoxious way Any reasonable answer would probably do. You would probably get more brownie points for asking what you need to optimize for (compute, storage) than providing what seems to be the best solution (using the sum trick).