This answer is the epitome of all of the answers here pointing probably in the wrong direction. The OP is basically saying any discussion of 'amortization' or

This answer is the epitome of all of the answers here pointing probably in the wrong direction. The OP is basically saying any discussion of 'amortization' or anything past something very simple, was completely beyond them. And your response, like many others here, is gong way off into the weeds, suggesting 'what they were really expecting' etc.. I definitely understand HNers willingness to go into the weeds for no apparent reason, but the lack of social comprehension here is really odd. The OP has reiterated over and over the social context and yet everyone seems to be happy to dismiss it whilst providing their bit of extraneous extra input. It goes on like a comedy. "But they must have been expecting this niche/novel thing way over here in the corner, and well if you didn't get that ..." It's as though the respondents are validating the poor ability of we techies to establish context. Any specific requirements in the interview, it would seem, could have been discussed by the interviewer and frankly without providing very specific contextual details, there's no such thing as a 'right answer' because it always 'depends'. And finally, why anyone would expect specific correct answers instead of a discussion about the constraints is also odd to begin with.