Knuth wrote Volume 3 just about searching and sorting, so there must be some interesting and challenging questions on the subject that could potentially be used

Knuth wrote Volume 3 just about searching and sorting, so there must be some interesting and challenging questions on the subject that could potentially be used in interviews. Not that quizzing people on random pages from TAOCP is a good technique, I'm just pointing out that if you're looking for a series of increasingly complex questions to ask in an interview, searching and sorting is a rich area.