how are these submissions judged ? do they reverse run taking the output as input and see if it satisfies the original input conditions ?
how are these submissions judged ? do they reverse run taking the output as input and see if it satisfies the original input conditions ?
| № | Пользователь | Рейтинг |
|---|---|---|
| 1 | Benq | 3792 |
| 2 | VivaciousAubergine | 3647 |
| 3 | jiangly | 3631 |
| 4 | Kevin114514 | 3574 |
| 5 | maroonrk | 3521 |
| 6 | strapple | 3515 |
| 7 | Radewoosh | 3461 |
| 8 | tourist | 3428 |
| 9 | turmax | 3378 |
| 10 | Um_nik | 3376 |
| Страны | Города | Организации | Всё → |
| № | Пользователь | Вклад |
|---|---|---|
| 1 | Qingyu | 162 |
| 2 | adamant | 148 |
| 3 | Um_nik | 146 |
| 4 | Dominater069 | 143 |
| 5 | errorgorn | 140 |
| 6 | cry | 138 |
| 7 | Proof_by_QED | 136 |
| 8 | YuukiS | 135 |
| 9 | chromate00 | 134 |
| 10 | soullless | 133 |
Yes
There is a special program (called 'checker') which, given input, desired answer and participant's output generate an outcome. Here you can read about testlib — library that is used on Codeforces to write checkers.
Sometimes check is straightforward, sometimes checking an answer for correctness is a separate interesting problem.