Cedar

The protocol question is very similar to this one: https://www.1point3acres.com/bbs/thread-1145830-1-1.html. I only got to the third question and there were some bugs. If you prepare beforehand, you have plenty of time (90 minutes). For each level, just pass all the test cases; I personally think you don't need to worry about complexity. Please give me some points to see interview experiences!