Hello Codeforces!
I previously shared a problem recommendation app, and now I've rebuilt it into a much more powerful service.
1. Precise and Fast Per-Tag Skill Analysis
While the previous app only used an ML model to recommend problems, CFRD computes per-tag ratings using Bayesian estimation. You can instantly see which tags — greedy, DP, math, graphs — are your strengths and weaknesses.
2. Weekly Marathon — Your Weekly Training Plan
No more wondering what to practice! CFRD automatically prepares 8 problems for you every week. Just run the Weekly Marathon!
3. Round Drills — Round-Level Recommendations for Real Improvement
Want to practice full rounds instead of individual problems? Round Drills classifies rounds into Comfort Zone — where you can build confidence — and Challenge — where you can push past your weaknesses, all based on your per-tag ratings.
4. Problem Picks — Target Your Weaknesses
Prefer solving individual problems? Problem Picks recommends problems to strengthen your weak tags and sharpen your strong ones.
Service: link
Any feedback is welcome. Thanks for trying it out!
It would be good to add the opportunity to change the number of problems in the weekly marathon.
Thank you for the suggestion! Customizable problem count for the marathon is an interesting idea. I'll keep it in mind for a future update.
What does CFRD stand for?
It stands for Codeforces Round Drills!
There are more training websites than people training ;)
most of them get down though, there was some website i used for practice, but it went down, i guess at this point people just do it to list it as some project they did in cv and when the work gets done they just don't care anymore and stop hosting the website
Totally valid concern. In my case I built this because I wanted a better way to train on Codeforces myself specifically doing full rounds instead of cherry-picking problems, and having a marathon-style weekly routine. I'm actively using it for my own practice, so it's not going anywhere as long as I'm training. Hosting cost is near zero, so there's no financial reason to shut it down either. Appreciate the interest though!
Fair enough
There are a lot of training sites out there. This one focuses on something most don't have the Round Drills, not just individual problems. It estimates your per-tag rating using a Bayesian approach, profiles each round by its tag distribution, then matches you to rounds that fit your strengths or target your weaknesses. There's also a weekly marathon mode (8 problems, A→H, mixing warm-up / weak-tag / random / strong-tag). So it's less "here's another problem list" and more "here's a structured training plan based on your actual profile." Thanks for checking it out!
In marathon after solving one problem, when I refresh data. No progress updated.
I've received similar reports. I'll find the cause and fix it. Thanks for the report!
I fixed this issue. Could you try accessing again and hitting the refresh button? Thanks for using the service!
Okey worked thanks. I have another suggestion, while fetching data from codeforces don't cover whole page by loading page. Instead, just make some loading animation for relevant elements that will be updated. That will improve the UI a lot.
Thank you for the suggestion! Your feedback really helps improve the UX. I'll work on applying that within the current architecture!
When i enter my username, it says client failed to fetch
Thanks for the report! I've improved the error messages — now it shows a clearer message when the CF server is down and also when a handle isn't found. Could you double-check your handle and try again? Let me know if the issue persists!
In the problem picks sessions, problems are refreshed everytime I fetch my profile. Is it an intended behavior?
The issue where problem picks were being refreshed without solving any problems has been fixed. Thank you for reporting!