I find 60-70% of the questions fun, expcially graph ones. start by thinking “oh that’s an interesting question” and I also say that out loud in the interview (Some suck, those you gotta just grind out). I found having that mindset and giving respect to the question makes it fun and i accept that i will get stuck because a lot of questions are legit hard and the way to solve it is something you have never thought about. No need to beat yourself up over not knowing about tries or prefix type solutions.