It&#x27;s really not a red flag. Not knowing or having BFS memorized does not indicate that one can&#x27;t implement it relatively quickly by refreshing oneself on the algorithms.<p>Unless, of course, you mean if all academic papers and material that describe BFS suddenly vanished and you had to come up with a solution yourself in 30 minutes with someone looking over your back. In that case, I agree, it&#x27;s a red flag for whatever position you&#x27;re interviewing for.