I don't think it's a complete waste of time to do these practice interview problems. At the end of the day it reinforces your understanding of core computer sci

I don't think it's a complete waste of time to do these practice interview problems. At the end of the day it reinforces your understanding of core computer science topics and helps you think out of the box(barring stupid problems where you need to know a specific formula). Then there are situations where you need a deep understanding of these algorithms to choose them for specific situations irrelevant of implementation.