Hello Codeforces Community and MikeMirzayanov, Recently,I and two of my friends shrek1234 and arnavra3 ,received a plagiarism warning on Codeforces for a problem we independently solved during a contest. We were surprised and confused to see that our codes had been flagged as matching, despite the fact that none of us discussed or shared any part of the solution during the contest.
We believe we are innocent – and here’s why:
The Problem Was Simple* The problem in question had a straightforward logic, and our implementation didn’t require any particularly creative tricks or unique code structures. As a result, it is very plausible that several solutions – written independently – would end up looking similar in structure, variable names, and flow.
For instance, if the optimal solution only needs:
- A single loop,
- A few conditionals,
And maybe some sorting or a greedy strategy...
Then the implementation space is naturally small. Many participants – especially those of similar skill levels and habits – may write strikingly similar code without any communication whatsoever.
The Real Issue – Detection Sensitivity The plagiarism detection system appears to heavily penalize structural similarity and perhaps token-level matches, even when the actual possibility of collaboration is practically zero.
What’s more concerning is that we know participants who:
- Copied entire code templates or solutions from ChatGPT or online sources,
- Made slight modifications (like changing loops or variable names),
- And still weren’t flagged.
This creates an unfortunate scenario where:
- Honest participants get punished for coincidence, and
- Actual cheaters manage to escape detection with minimal effort.
This is not just about our rating or our profiles. It's about keeping the spirit of Codeforces fair and strong. If the system makes too many false positives, it could discourage honest coders and create a sense of injustice.
We also request the setters bashkort and TheEvilBird to look into the issue and review our submissions once.
The submission links are: - Shrek1234: https://mirror.codeforces.com/contest/2113/submission/324501156 — Slamix:https://mirror.codeforces.com/contest/2113/submission/324476418 Arnavra3:https://mirror.codeforces.com/contest/2113/submission/324510734
We urge the Codeforces community to highlight this problem which can happen to anyone and help build a better and fairer platform together.
Can you link the submissions here for us to see?
its maybe 2118A - Equal Subsequences
324048172
324055660
324048677
this part is very similar for all three of them
You should read the comments below. Using the same template is popular, especially because the three of them are friends.
Shrek1234:https://mirror.codeforces.com/contest/2113/submission/324501156 Slamix:https://mirror.codeforces.com/contest/2113/submission/324476418 Arnavra3:https://mirror.codeforces.com/contest/2113/submission/324510734
Another important thing to note is that the editorial solution is also the exact same as that of ours only thing that differs is that it is in python.
The B problem solution is quite straightforward, so there is a high chance that much of the code will overlap. However, the snippets of three of yours are quite similar, so maybe that's why the codes are flagged. I've heard from somewhere that including big ASCII images in the snippet will also result in a flagged code. Maybe you should seek help from the headquarters or the contest organizer.
I still do not know why plag check exists for simple questions , the editorial solution and my solution is the exact same like literally exactly the same https://mirror.codeforces.com/contest/2113/submission/324510734
Yes bro this question can have multiple same solutions
What a coincidence:
324476418
324501156
324510734
I'm not even kidding , the idea is the exact same we all use the same vsc formatting , if we really tried to cheat why would we not change the variable names or do some weird shit.
It's like writing code for the sum of elements on an array , it's going to be the same. But this is even worse because all the variables were stated in the problem statement itself so everything is going to be same
Vladosiya orz
this is just sus at this point lol
Did the author of the editorial copy their solution? Like the structure of codes is similar, but the code of editorial has the same. This is not a type of problem which can determine cheating, since there are only a few ways to implement the idea.
I found the C submissions of Slamix and shrek1234 to be exactly same as well
324494353
324505865
Any comments on this?
How are both our codes same
The intended solution is also prefix sums and checking how many gold cells are there in a square of size k.
If this is considered to be cheating then everyone who uses prefix sums in this question should be considered cheating cause as far as I know there is only one way to make prefix sums
Your codestyles are really similar. I can see that all variable names are different, but the codes feel really similar
This whole scenario is really sad cause all of us know tons of people who actually cheat and don't get caught and now we got flagged. Like it's such an extreme coincidence that we can't even defend ourselves since all of us write similar style of code.
Life is unfair, learn to cope somehow, change codestyles maybe. It's really strange that your codes match that good
Ye I understand but this is literally my 2nd time , my first time I used some gfg code and got flagged. Now cause of this it looks even more sus very funny now
Our learning patterns were similar and may be this was the reason for our codes to match. Moreover, this is the first time to occur in over so many contests which we have given.
I have also received plagiarism warning for the problem — 2113B . It was a simple problem. We just have to check the remainder of the absolute differences of the x and y coordinates and multiple people can have same code. I am honestly telling that I have not done cheating. I received warning because I submitted later.
My submission-https://mirror.codeforces.com/contest/2113/submission/324495145
Other user submission-https://mirror.codeforces.com/contest/2113/submission/324488785
Even the editorial code is exactly the same as ours.
I doubt every blog where author says "me and my friends got plagged"
He didn't even get plagged , he wrote the blog for us and I'm grateful to him.
I've seen lots of codes of B and many of them have the same logic exactly but we are the only people who used return; and have similar templates , so naturally we got flagged. We can only state this and cannot prove ourselves any further.
Auto comment: topic has been updated by Slamix (previous revision, new revision, compare).
Auto comment: topic has been updated by Slamix (previous revision, new revision, compare).
what a coincidence
all 3 are from same college and i guess same batch
please ban them MikeMirzayanov
Support
This is the first time they got flagged so they will not get banned yet :v
Just funny at this point , i got flagged back when i started cp , when i used a gfg thing i.e a pre published source code , and now again i got flagged for this :pray:
I thought using pre-published code was legal??
ya it is legal , but no one looked at the appeal ofc , i was new at that time so i just wrote 2-3 comments and directly messaged headquarters thinking they'd do something lol
The headquarters are busy so they never respond to the messages
yes i was new user back then
Bad luck I guess
I know the algorithm needs to be trained
because one of you is cm and other one is expert so i dont think that they will cheat for B
may be both of them learns together so their writing style is similar
or might be they have cheated but i request to authorites to re-evaluate their submissions
I solved D as well in that contest just to get flagged :pray:
Was CM*
Is
ok bro
why to encourage cheaters to reach the banning threshold?
by the way, vivekpal__24 got banned in his first skip :D
I think this is because of the plag detection algorithm and not of any faults. Even the editorial code is same as mine , then would you put a plag on the authors as well.
are you sure? maybe u shouldnt plagiarize again lmaooo
Well, I agree it’s hard to believe, and maybe I wouldn’t have been convinced if it had happened with some random group of three friends but I know them, and I can vouch for them. If I talk about arnavra3, he’s the best coder of our year. One might argue that he cheated to get to ICPC regionals, but finishing in the Top 30 in Chennai Regionals is not something you can attain if you’re just a pitiful Problem B cheater. He does have a plagiarism instance, but he also has a comment specifying the GFG code he used.
As for shrek1234, he too cheated at the start of college, but he admitted it to our seniors, and despite that past, he ground through practice and improved on various platforms. He has given 60+ contests without any malpractice so if he realised his mistake and improved this is not what he deserves.
Slamix doesn’t even have a plagiarism record.
In the end, I just want to mention that these are coders who have gone from Expert to Pupil they have experienced the downfall, competed in numerous contests, and solved many problems. Cheating on a Div 2 B is not something they would do. They are my friends, and I vouch for them.
I vouch for the comment that vouches for arnavra3, shrek1234 and Slamix
I vouch for the comment that vouches that vouches for the comment that vouches for arnavra3, shrek1234 and Slamix
I vouch for the comment that vouches for the comment that vouches that vouches for the comment that vouches for arnavra3, shrek1234 and Slamix
maybe we should solve it wrong on purpose to stay safe