I want to report ray2002 for his submission 126891357 which was directly copied from ideone which was provided in this video. Several others also copied from this youtube channel as there were 100+ people watching the live stream.
He did manage to add and extra function in place of is_sorted() and a bunch of macros and was able to bipass the plag check (if such check was done).
Ohhh noooooo someone copied Div 2A. baaaan him!!!!
after div 2A goes div2B, after that — div2C and so on. if we will ignore such issues, we will loose honest contests -> codeforces
Hehehe, this was one of the cheaters that I have caught in my recent blog. (I am talking about the YouTube channel)
I wasn't sure if he gives links to the solutions of Codeforces contests, but now I am sure that he is.
Now I have a dilemma: should I provide links to Telegram channels and groups that I have found in previously mentioned blog?
P.S. This is an example of a really helpful cheater report blog -- it says not only about the cheater but about the resource with a lot of cheaters.
Several other users were caught plagiarized from the same https://ideone.com/necSt5 code, as per reported by our Telegram group. They have noticed a common timing for all these solutions, i.e., 21:45 (as per the IST).
The list of the submissions are provided below (not in sorted order).
It's a humble request to MikeMirzayanov to skip all of the submissions as per the CodeForces code of conduct. Thanks!
I'm almost 100% sure that this person cheated (based on looking at their other attempts for the same problem). And this person also had been already flagged by the plagiarism checker in the past. The codeforces plagiarism checker is already pretty good at catching this kind of cheating and we just need to wait a bit longer until the plagiarism check is actually finished. I'm fairly confident that ray2002 was going to be flagged by the plagiarism checker even without your blog post.
Thanks for sharing the original master copy of the cheater solution after the contest via posting that ideone link. The master copy and the time of it becoming available indeed may be useful for identifying cheaters.
But I think that linking to youtube/telegram/discord is unnecessary and even harmful. Some people may start following that solution distributor person (no matter how unimpressive his/her skills are) with the intention to copy his/her solutions during the future contests too. Your blog post speculating that ray2002 "was able to bipass the plag check" also unnecessarily gives the wannabe cheaters false hope and I see this as a form of entrapment.