I'm not sure why you assume it has to be hundreds of hours. Take a look at something like https://github.com/jwasham/coding-interview-university https://github.

I'm not sure why you assume it has to be hundreds of hours. Take a look at something like https://github.com/jwasham/coding-interview-university https://github.com/jwasham/coding-interview-university, which has a lot of different topics. In interview loops I've done recently, I realized I was most nervous around Systems/Scaling and Graph (e.g. Dijkstra's) questions, so took some time to work on those. You don't have to do like the author of that piece and work for hundreds of hours. If trees are proving a problem or are an area you know you aren't so up on, then use studying to fill in the gap. Anything is better than nothing, and studying for, let's say, 10 hours might make you just more comfortable with the topic to turn the interview in a more positive direction. (Disclaimer: I have a academic background from years ago, just haven't used most of these things in years, since like everyone here has admitted, it isn't regularly a part of day-to-day life)