Hello, Codeforces.↵
↵
I've participated a few rounds and noticed that there are **too many cheaters**.↵
Now the cheater detection is community-driven and only a few of cheaters are being detected.↵
↵
###Idea↵
I’m proposing Codeforces Anti‑Cheat (CFAC) – an automated flagging system that works after each contest and automatically detects cheaters using:↵
↵
— **NLP-model based submission (and maybe replacement) checking**↵
↵
— **Timings-based detection: if gray solves div.2 e in 3 mins, its suspicious**↵
↵
all of these metrics are combined into suspicion score matrix where score[u][p] is value↵
normalized [-1, 1] where ↵
↵
— -1 — if participant $u$ 100% not cheating at problem $p$; ↵
↵
— 1 — if participant $u$ 100% cheating at problem $p$;↵
↵
### Need help↵
[user:You,2026-03-24] I need help in↵
↵
— collecting labelled data for cheaters and not cheaters↵
↵
— final testing of anti-cheat system↵
↵
###Updates↵
- Created cfac [repo on github](github.com/vn4ka/cfac)↵
- Updated post text without AI addressing hate comments about AI-slop and [user:pilliamw,2026-03-24] blog post
↵
I've participated a few rounds and noticed that there are **too many cheaters**.↵
Now the cheater detection is community-driven and only a few of cheaters are being detected.↵
↵
###Idea↵
I’m proposing Codeforces Anti‑Cheat (CFAC) – an automated flagging system that works after each contest and automatically detects cheaters using:↵
↵
— **NLP-model based submission (and maybe replacement) checking**↵
↵
— **Timings-based detection: if gray solves div.2 e in 3 mins, its suspicious**↵
↵
all of these metrics are combined into suspicion score matrix where score[u][p] is value↵
normalized [-1, 1] where ↵
↵
— -1 — if participant $u$ 100% not cheating at problem $p$;
↵
— 1 — if participant $u$ 100% cheating at problem $p$;↵
↵
### Need help↵
↵
— collecting labelled data for cheaters and not cheaters↵
↵
— final testing of anti-cheat system↵
↵
###Updates↵
- Created cfac [repo on github](github.com/vn4ka/cfac)↵
- Updated post text without AI addressing hate comments about AI-slop and [user:pilliamw,2026-03-24] blog post



