I've been grinding 1900-rated problems lately and got completely walled by 1909I.
https://mirror.codeforces.com/problemset/problem/1909/I
I spent way too much time on it, finally checked the editorial and the solution involves advanced polynomial tech like NTT. I checked clist and it's rated around 4000.
Is the rating just completely bugged? If so, admins please fix it. But if the 1900 rating is actually correct, could some high-rated coders explain the simpler way to think about this?
Thanks!
Rainboy does it. Gets rated 1900-2000.
Nah man, it's basic knowledge
Seems to pretty clearly be a bug. It's not even a rainboy issue; rainboy didn't actually solve it until after contest. Based on the standings, it had no solves during contest, so it surely cannot be below 3500.