The difficulty level of some problems seems to be well below or above what the rating indicates, so I was curious as to what criteria problem ratings are calculated upon.
The difficulty level of some problems seems to be well below or above what the rating indicates, so I was curious as to what criteria problem ratings are calculated upon.
| № | Пользователь | Рейтинг |
|---|---|---|
| 1 | Benq | 3792 |
| 2 | VivaciousAubergine | 3647 |
| 3 | Kevin114514 | 3603 |
| 4 | jiangly | 3583 |
| 5 | turmax | 3559 |
| 6 | tourist | 3541 |
| 7 | strapple | 3515 |
| 8 | ksun48 | 3461 |
| 9 | dXqwq | 3436 |
| 10 | Otomachi_Una | 3413 |
| Страны | Города | Организации | Всё → |
| № | Пользователь | Вклад |
|---|---|---|
| 1 | Qingyu | 157 |
| 2 | adamant | 153 |
| 3 | Um_nik | 147 |
| 3 | Proof_by_QED | 147 |
| 5 | Dominater069 | 145 |
| 6 | errorgorn | 142 |
| 7 | cry | 139 |
| 8 | YuukiS | 135 |
| 9 | TheScrasse | 134 |
| 10 | chromate00 | 133 |
I think it has something to do with the amount of submissions the problem records within a contest,you'd notice a lot of div3 D's and E's are rated 1400-1500 but are considerably easier than a div2C or a div1A of the same rating.
Yea that does make sense
i think it has to do with the amount and the rating of people solved it during the contest, also div2 problems that get a rating of 1400 — 1500, sometimes are harder than div3 problems getting rating of 1500 — 1700
A problem gets a rating of X in a contest if 50% of participants of rating X solved it during the contest
Ah I see Do you have a source for this??
As far as i know Codeforces uses the ELO rating system
To calculate the performance of a problem we need to see how many participants of which rating it defeated during a contest(participants that failed to solve it), then you use the ELO performance formula to calculate its rating.
Now we can arrive to a Winning probability table based on ELO difference where you can see that if the rating difference gets close to 0, the winning probability gets close to 50%, thus if a problem defeated 50% of participants of rating X the problem has a rating of X.