Onsite interview, four interviews total. The first three are all solving algorithm problems. The last one includes behavioral questions and then algorithm problem-solving. Some problems are classical interview questions that can be found on the internet with perfect answers; others are original, and I've never seen them before.

Interviewers might ask you to write code on paper or on a MacBook. The schedule is really tight, with one interview right after another, including a single lunch break in between. You then wait about 10 days to get feedback.

I think you have to be careful about details, recursive algorithms, and basic data structure implementation. For example, you might need to implement a heap by yourself. You can also be asked to prove your algorithm's correctness.

Be smart and aware of details. That's all.

Merge K sorted lists.