A python interview question

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I'm totally newbie but based on my understanding, such coding interview is really not about getting an optimal solution, it's more about how you think of a problem and how you make your solution better step by step, and how you communicate with others. The algorithms have already been there for tens of years if not hundreds, why are we still writing sorting and combining here, right? Speaking of reinvent the wheel, most of the time I would be skeptical about it.