The problem is that the problem you think the interviewee hasn't seen is derived from common problems the interviewee has seen. 99% of the time, if the intervie

The problem is that the problem you think the interviewee hasn't seen is derived from common problems the interviewee has seen. 99% of the time, if the interviewee has a background in programming competitions then they will sound very intelligent, and the further they move from that background the worse they'll do. You're selecting for familiarity, not creativity.