For me this puzzle had the greatest divergence between complexity and difficulty. It was fairly easy to reason about what to do but of course the first naive solution that solved for the test input by tracking the content of every node was far too slow for the actual input.
I solved part 1 after realizing I only needed to track the ranges of intersection on a single line, and then I used that same trick in part 2 to avoid having to check every single point since I could get the intersection for the current x value and then skip to the end of the y range. Took less than 3 secs on my laptop.
