I had come up with O(N^2) solution which he wasn’t satisfied and asked to do it in O(N). I still tried and asked if I can get a clue, to which the reaction was harsh. DUDE please make the interviewer comfortable. We come in pressure obviously. Sometimes we blank out. It’s not like we don’t know stuff. I’ve prepared to solve Graphs and Trees, so arrays aren’t difficult to solve. The interviewer told me I should prepare before coming to interviews. I suggest folks to solve all Hackerrank problems if not you’ll be judged as incompetent.