Honestly, these are probably bad interviews. I do like wasting time on puzzles and code golf, but for job interviews such question are mostly out of place.
In 90% of cases to propose such a problem in a stress situation like a job interview and you filter by success, you filter by those that already solved the general problem.
In 90% of cases to propose such a problem in a stress situation like a job interview and you filter by success, you filter by those that already solved the general problem.