Painful. Started with bumpy introductions (from the interviewer) then on to the coding challenge. I interview candidates regularly at my job and introductions are usually the easiest part but I figured maybe this was the interviewer's first time. The coding starts and I explain my thought process and the code as I write it. During this I pointed out that I almost never have the optimal solution on the first go. Generally I find a solution then optimize it but as things progressed it seemed the interviewer expected a minimal complexity- character-for-character solution on the first try. By the end what started as "find the intersections" became "count the occurrences" while finding the intersections but also reducing complexity and use a literal object but not as a hash map like you mentioned in the beginning. The hints became so misleading I wasn't even sure of the problem I was solving anymore and the interruptions to my solution completely fried my ability to think through the problem. Needless to say I did not pass the interview but towards the end I frankly didn't want to. I was stuck trying to understand the requirements and their expected solution but when I asked for clarification I received the equivalent of "google it". At the end of a failed interview there is no reason the interviewer can't explain the solution he or she was looking for... unless they can't explain it.