Codeforces has a treasure trove of problems across many topics—whether it’s greedy algorithms, dynamic programming, data structures, or graph theory. I’m curious to know: what is your favorite topic?
And if you have a problem that represents that topic, please share it in the comments! If you include a link to the problem, don’t forget to write its name next to it.








Auto comment: topic has been updated by Ermiooo159 (previous revision, new revision, compare).
4A - Watermelon math
Same
781D - Axel and Marston in Bitland Matrix multiplication, optimization techniques.
https://mirror.codeforces.com/contest/375/problem/D DSU on tree