454 karma · joined July 10, 2018
it's not that the questions are too hard, it's that the whole challenge is bogus. if you have to ask these questions, make it a take-home challenge and discuss the implementation with people when they come to the in-person interview. being able to explain the hows and whys of already-written code is much more valuable than being able to write code under pressure, and much closer to what someone would actually be doing at work.
even better would be to figure out what exactly you're looking for in candidates and design the interviews to reflect that. right now it seems like you're looking for people who are good at coding under pressure... is that a normal part of the job? it very well might be, but i doubt it. think more about what you really want from people on a day-to-day basis.