I’m trying to understand how Yukicoder problem difficulty (1–5 stars) compares to Codeforces ratings. If you have experience with both platforms, I’d really appreciate your thoughts on questions like:

Roughly what CF rating range corresponds to each Yukicoder difficulty?

1★ → CF 800 ~ ?

2★ → CF ? ~ ?

3★ → CF ? ~ ?

4★ → CF ? ~ ?

5★ → CF ? ~ 3500

Do Yukicoder problems feel more implementation-heavy, math-heavy, or trick-based compared to CF?

Any notable differences in difficulty consistency or problem style?

For reference, I’m thinking in terms of CF ratings from ~800 to ~3500. Thanks in advance for sharing your experience!

If you open the problemset status page, you’ll notice something strange. Many users with randomly generated names (basically random letters and numbers) have made a huge number of submissions. These submissions are mostly for recent problems, one by one, and almost all use Python 3. If you click on any of them, you’ll see that they submit about once every two minutes. The code in these submissions looks very similar, so I suspect these users are actually AIs.

Here is a screenshot of a problems.

And another screenshot of a user.