The first round interview was a nice experience. The interviewer was very patient and interactive. The coding problem required some background, and he helped me to go through an example on Wikipedia. Feedback was given in a timely manner. At the end of the interview, he answered my three questions, and I felt it would be nice to work with someone like him.

My second interview experience was really bad. The interviewer came up with a problem that was very unclear regarding the goal and the solution. He didn't give me useful feedback and imposed many restrictions. At last, the interviewer said, "Time's up, and have a good day," to simply end the interview.

Cuckoo hashing