One more reason why this is terrible question: many people solved it in the past as part of a programming course, many didn't. If you want to test which school

One more reason why this is terrible question: many people solved it in the past as part of a programming course, many didn't. If you want to test which school they went to you can look at the resume. If you want to see how they handle writing solvers for simple games/puzzles under pressure of the interview come up with one that is guaranteed (or almost) to be new for the interviewee.