Whether you admit to having seen a problem before is up to you but make damned sure you are able to keep your story straight if you don't. We had a candidate s

Whether you admit to having seen a problem before is up to you but make damned sure you are able to keep your story straight if you don't. We had a candidate say they hadn't seen one of our warm-up problems before when explicitly asked only to later find out that one of our folks had accidentally used the same question for the phone screen. It's never a point in the candidate's favor if there's suspicion that they lied about something. Really though, if you think LeetCode style questions aren't worthwhile but the employer does, there's a big cultural mismatch between you and them already. Simply go elsewhere and both of you will be happier in the end.