Comment by seiji

Often it's completely free-form too. So you have to pick the language, the data model, the data structures, the traversal mechanism (recursive vs. iterative), state to track (allow duplicates? prevent infinite loops?) and how to test the example all at once before even getting _started_ with their problem description.

Many of the interviews could actually work if they broke the process down into 8 questions instead of one (how would you represent a tree? a binary tree? how would you find node X? how would you move node X to the other side of the tree?). But, the ability to accommodate understanding takes empathy and human connection, not being a jerk programmer on interview duty who is browsing HN while listing to the interviewee mumble on your speakerphone.

Never underestimate the lack of ability in the interviewer and not the interviewee. Except, the company always believes itself to be more competent than outsiders, so you're ultimately left with being condescended to unnecessarily.