I believe the “evidence” he listed could either be obtained simply by **looking at the number of solves**, or was completely useless information. For example:↵
↵
* `***`had a large performance gap between contestants / some problems were hard / some were easy. (The problems were already ordered by difficulty & This is just a personal judgment and should not be taken as a reliable reference and you could also see the number of solves, so was this useful at all?)↵
* `***` did not solve problem `***`. (Was this useful in any way? Could it help anyone solve or pass a problem?)↵
* The scoreboard was not misleading. (Was this useful? And couldn’t you tell that just by looking at the scoreboard?)↵
* There bugs on CF. (Was this useful?)↵
↵
If you participated in the contest, I believe nothing I said would help you solve any problem. If you did not participate, then it was even more useless.↵
↵
It was just an online contest. As long as you did nothing unfair, such as cheating or revealing solutions, I think reasonable discussion should be allowed(for example, saying that `***` was rank 1 or that `***` solved problem `***`), since all of this information was public.↵
↵
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↵
As for the reused problem, we indeed did not find any similar problems on CPRet or yuantiji, but during the contest, someone pointed out that 1F had previously appeared in a research paper.↵
↵
We sincerely apologize for this. The duplicate happened because our plagiarism checking was not thorough enough. However, since the problem has already been used and I believe it is a high-quality and educational problem—perhaps even the only useful problem involving this particular concept—I think it would be better to enjoy the problem rather than continue complaining about it.↵
↵
You can downvote this blog if you want.↵
↵
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↵
By the way, Codeforces does seem to have a display bug: under certain conditions, some users may see an incorrect problem statement, which has been confirmed to be an older version. I sincerely apologize if this affected your attempt, but I do not believe this was my fault.↵
↵
And can anyone recommend some good methods for checking whether a problem has appeared before?↵
↵
We couldn’t find 1F using CPRet or yuantiji, because its possible sources seem to be:↵
↵
1. A Tsinghua University assignment from about ten years ago;↵
2. A Codeforces blog post from at least eight years ago.↵
↵
I’m not sure how we could have checked for duplicates in a situation like this. Does anyone have a good solution?↵
↵
↵
* `***`had a large performance gap between contestants / some problems were hard / some were easy. (The problems were already ordered by difficulty & This is just a personal judgment and should not be taken as a reliable reference and you could also see the number of solves, so was this useful at all?)↵
* `***` did not solve problem `***`. (Was this useful in any way? Could it help anyone solve or pass a problem?)↵
* The scoreboard was not misleading. (Was this useful? And couldn’t you tell that just by looking at the scoreboard?)↵
* There bugs on CF. (Was this useful?)↵
↵
If you participated in the contest, I believe nothing I said would help you solve any problem. If you did not participate, then it was even more useless.↵
↵
It was just an online contest. As long as you did nothing unfair, such as cheating or revealing solutions, I think reasonable discussion should be allowed(for example, saying that `***` was rank 1 or that `***` solved problem `***`), since all of this information was public.↵
↵
---↵
↵
As for the reused problem, we indeed did not find any similar problems on CPRet or yuantiji, but during the contest, someone pointed out that 1F had previously appeared in a research paper.↵
↵
We sincerely apologize for this. The duplicate happened because our plagiarism checking was not thorough enough. However, since the problem has already been used and I believe it is a high-quality and educational problem—perhaps even the only useful problem involving this particular concept—I think it would be better to enjoy the problem rather than continue complaining about it.↵
↵
You can downvote this blog if you want.↵
↵
---↵
↵
By the way, Codeforces does seem to have a display bug: under certain conditions, some users may see an incorrect problem statement, which has been confirmed to be an older version. I sincerely apologize if this affected your attempt, but I do not believe this was my fault.↵
↵
And can anyone recommend some good methods for checking whether a problem has appeared before?↵
↵
We couldn’t find 1F using CPRet or yuantiji, because its possible sources seem to be:↵
↵
1. A Tsinghua University assignment from about ten years ago;↵
2. A Codeforces blog post from at least eight years ago.↵
↵
I’m not sure how we could have checked for duplicates in a situation like this. Does anyone have a good solution?↵
↵
