FPS 24

28-Sep-2026

I followed the same guidelines I have for Project Euler: no genAI (of course), but I could refer to any online materials as long as they were available before the original contest date (November 2025).

I would like to thank Yosupo Judge for having so many formal power series problems, and those who regularly use it to optimize their libraries. The stuff people do there is crazy; I mostly borrowed it wholesale whenever I needed to. That's why some of my submissions are in the tens of thousands of bytes.

Beyond the template bashing though, the problems were delightfully non-trivial, especially the last few. I don't think completing this problem set was the hardest thing I've ever done, but it's decently up there.

I haven't really looked at other people's write-ups (they're mostly in Japanese, naturally), but I get the feeling that some of my solutions were incredibly cursed and/or unintended by the problem authors. So I might write an unofficial editorial on the Serviette sometime soon, who knows.

That's all from me. I am now slightly closer to knowing how Elegia's mind works.