Today I received a message saying that my solution for problem D of Codeforces Round #733 coincides with more than 20-25 other submissions. First, I got a little confused but now I have an explanation for this.
stopcheatingmyself was in the same room as mine during the contest. I had submitted my solution for problem D at 0:44. He submitted his solution at 0:57 and immediately locked the problem. He then probably saw my solution and leaked it. I am also attaching screenshots of the timestamps to prove my point.
Timestamp of my submission — 
Timestamp of submission by stopcheatingmyself - 
Moreover, I have given around 120 contests and I have a very clean record. I have also been the setter of Codeforces Round #730 (Div. 2). Such things clearly show that I am not a cheater.
I would request MikeMirzayanov to look into this matter and revert my ratings and solutions back as clearly there is no fault of mine in all this. I would also request him to do something in this regard so that the hacking feature isn't exploited such shamelessly again in the future. I remember that someone else had also raised this issue in the past but it was ignored.
Totally agree with you!
stopcheatingmyself is a regular cheater of codeforces. One can clearly see his submissions.
He has been cheating constantly in past contests.
JaySharma1048576 is innocent.
MikeMirzayanov please ban stopcheatingmyself.
I think that this guy stopcheatingmyself is someone's alt account. He submits the leaked solution and then quickly locks it. Then goes to his room and copies the code of some high-rated coder.
Hacking feature is being exploited shamelessly!
MikeMirzayanov sir please look into this
Nothing ignore
It is a feature of Codeforces. Room is a place where one can hack other's solutions during a contest. One needs to first lock his submission so that he is not able to make changes to it later. Then he can go to his room and then see and hack the solutions of others in the same room.
There are couple of youtube channels which provide solution code during contest is running please help to stop this kind of leakage.
Some of them Arsalaan Ahmed 09,Albert's lectures please report these channels
That wouldn't really work, the plagiarism check would catch that the code he submitted on his main matches the code of the high-rated coder, right?
I think so too, he could also just understand their approach and code it in a way to avoid plag check.(not sure about this)
See the past confession of stopcheatingmyself
He himself admits that he has been cheating from telegram
This is pretty disturbing. Only educational round hacks seem to be cheating proof.
Do you have an explanation for your participation in this contest?
Moreover, my understanding is that in the case of having multiple coinciding solutions, the solution with the earliest timestamp is never penalized. Unless the cheating hackers have a time machine, they couldn't have submitted a plagiarized version of your code with an earlier timestamp than your original version. Can anyone explain what's going on?
About my solutions in Round #700 — I wasn't feeling confident for the round. So, I had initially submitted my solutions from an alternate account, Need_For_Sleep_MW but since I preformed quite well in that round, I submitted the same solutions from this account too and I got plagged for that. I accepted that it was my mistake, didn't complain about it and decided to never repeated that again.
For the first solve, I don't know if that is a thing. Out of all the solutions against whom my solution has been plagged, I have the least submission time. Currently, only my solutions have been skipped and I haven't lost any rating change yet.
The system really works this way. Here's one of many examples of two coinciding solutions. You can see that 120536673 was accepted and 120543231 was skipped.
Mike will probably check your case. If the system is actually functioning properly, then one of the coinciding solutions somehow happened to be submitted earlier than yours. Your submissions wouldn't be skipped otherwise.
https://codeforces.com/blog/entry/8790?#comment-818168
You can see all the plagiarised solutions in this comment and from the id of the solutions, it is quite clear that my solution is the earliest one.
Testing your codes with a fake account, nice. A very clean record indeed.
Sir Errichto, We all love you in CF! Sure he did something illegal. Still I think his evil inside tempted him to do this to get some rating! He didn't intend to cheat:) (He wouldn't have solve div2-A&B if he really intended to cheat)
don't watch too much anime
At least his main account's record is clean. (kind of XD)
B R U H
But you have been involved in cheating in some or the other way I would say (Round #700), this is clearly against the contest rules of Codeforces. Isn't it? Being a round setter or high rated coder doesn't wash you off your past sins.
Edit: And this is not even way back like you did this 10 years back, just a few months back so you just can't get off by saying you did this and will never do this again. Now also someone exposed you, you didn't bother to write post back then that I am sorry for violating Codeforces Rules
I would even take one step further and say that being a writer and a high rated one should increase the severity of his rule violation.
Maybe Codeforces should give the benefit of the doubt to the first person who submitted the code and only put out of the competition the users who supposedly copied it. That is, if two users submit the same code only the one who submitted later gets in trouble.
You have good point but there is one problem in this. if Codeforces applies this policy then people will share there code with their friends or to someone else because they will have no fear of getting plagiarized because they have submitted it first. But to share your code intentionally with someone is also wrong.
If someone gets repeatedly in this situation then they should be punished too
Also other guys obfuscated their code, this clearly show that they copied jay sharma code.
They have ruined Codechef by doing this and trying to ruin CF. JaySharma1048576 clearly exposed him.
at least we know hacks is still alive in cf
I think JaySharma1048576 is not involved in any plagiarism. He is outstanding in competitive programming and has also done problem setting in Codeforces and Codechef. Admin should necessarily check for any exploitation of the hack rooms and revert this falsely made verdict against him.
Wow this is a whole new low for these cheaters. I hope you get justice.
Do I need to say anything?
How did Mike reply?
looks like he typed
stopcheatingmyself is banned
I feel bad for Mike, because he put so much effort and time in making this platform and now from last 1 year some people are trying to ruin it. Hacking a solution isn't a new concept and many people knew about this loophole, but it was never exploited to this level before (correct me if I'm wrong).
I used to cheat frequently and know a lot of ways to cheat effectively! Is there anyway that I can expose these cheating methods to admins? MikeMirzayanov seems really busy nowadays and I can't send message to him
Sorry, but I have no opportunity to carefully parse messages like yours and to answer them. Do you give permission to post a couple of examples here?
Thanks for the reply :) Im afraid if I write here many cheaters also see this and learn cheating tricks. I'll message you in CF talks.
I will carefully study all the details. Most likely, in this case, I will later roll back the punishments. I note that, unfortunately, the topic writer has already been previously convicted of violating the rules. Moreover, he continues to use the second account, which is a violation. The claim that his reputation is crystal clear is not obvious.
However, regarding the situation with cheaters. You can see that the situation is very difficult now. Every round I spend hours finalizing the results. It is long, painstaking, difficult, and tedious. However, taking into account the current number of participants, there is no way to delve into each case individually. I do not have the opportunity to spend hours on each difficult case, to listen to different opinions, to arrange a long trial. It is normal that there is a small percentage of false-positive verdicts. But this is precisely why the punishment system is very loyal to the first violations.
Many of you write about the need for a system with which you can report cheating. Most likely we will implement this. However, everything is not so easy. Reports must be processed carefully. Reports can be easily misused. The opinion of the majority does not always correspond to reality (look at votes on posts and comments). Maybe we will try to select a group of trusted members who will help and participate in the process. But I'm not sure if this will work well. I myself have been doing this for 10 years and I am sure that this is a heavy and painstaking job. Few people want to do this for a long time.
Thank you sir for looking into this. I am extremely sorry about using an alternate account and I promise to never use it again. You can even ban that account if you want to. My sole purpose of creating that account was to give Division 1 contests and combined rounds because I wasn't confident enough and was afraid to lose rating. But I never had the intention of cheating with anyone else.
Good job sir. Wish the bests for you.
Very good job sir,thank you for giving us Codeforces, I hope you take care of yourself.
he continues to use the second account, which is a violationso no
he continues to use the second account, which is a violation
Just asking, Is there any rule here stating that having more than one id is a violation of the law?
Click on the button 'Help' on top. Jump to Point 6.1: "Don't create more than one account, if you have forgotten the password, use the password reminding system. "
The alleged use of the hacking feature didn't have any effect in this particular incident. I have parsed the list of submissions from https://codeforces.com/blog/entry/8790?#comment-818168 and this is what they look like (sorted by timestamps):
Indeed, JaySharma1048576's solution 122805324 has the earliest timestamp. But xianxoo submitted a very similar solution 122806405 at 00:46:36 (only 2 minutes and 9 seconds later). This happened long before stopcheatingmyself locked their solution at 00:57:50 and had a chance to look at JaySharma1048576's solution via the hacking feature. There were 6 contestants, who submitted similar solutions before 00:57:50.
So the hacking feature isn't to blame for leaking the JaySharma1048576's solution. At least not this time. And whether hacking can or can't be abused to leak solutions in practice is another question.
How are solutions of xianxoo and others similar to mine? They are similar to each other but aren't similar to mine. All of those solutions use vectors and many casework while my solution is purely based on sets and there is almost no casework involved. Even the outputs are different on every test case.
An important correction to that: "what the plagiarism checker thought to be very similar". Upon manual inspection, JaySharma1048576's solution actually looks pretty different to me. And now I wonder whether anyone actually submitted anything that resembles the original JaySharma1048576's solution.
There is only one submission that looks similar to mine and it hasn't been included in this list by the author of the comment but it was in the message I received — this
Edit — There are more like this and this. Everyone knows that akash_ramjyothi is a famous cheater and even I have exposed him many times in Codechef.
Could you please provide a complete list of coinciding submissions from the message that you received? As I mentioned in an older comment, there has to be some submission that the plagiarism checker considered to be similar to yours, but with an earlier timestamp.
But yes, that C++ submission 122837812 done by the Python user is super suspicious. It almost perfectly matches your submission, but has a bunch of variables renamed and has differences like
s.rbegin()->first>=2vs.s.rbegin()->first>1.I have received only 3 messages till now. In the first one, the solution 122837812 was mentioned. In the second one, the huge list of the submissions which you have already checked were mentioned. And in the third one, the latest two submissions were mentioned. If I receive any more, I will add them in my previous reply.
Wow, this blog totally took me by surprise, how can people big brain to copy someone else's solution by using the room feature and leak them during an ongoing contest :(
Room is a pretty unique and good feature that codeforces has and really sad to see people using it in a bad way.
Every other halfwit becomes a expert/CM by cheating nowadays. Unless you are giving Div 1 , I feel you should stop judging yourself and maybe adopt the Rainboy style (maybe start from D/E if not the last question).
Author of this blog cheated again see his submissions of goodbye 2021
all are skipped
such a shame.
Not taking any sides, but the solution which was skipped was short and simple! And according to his comment on the 3rd party violation blog, only A got plag, and I guess it was a fairly easy problem, dunno if more problems were caught by plag checkers or not
I got the message that my solution for only Problem A of Goodbye 2021 coincides with another one. This was a very easy problem (just take absolute values and find frequencies using map) and it is completely possible for such a coincidence to take place in such an easy problem with such a short and natural solution. Moreover, my solution was submitted just 2 minutes after the start of the round (including one Wrong Answer submission just 1 minute after start of the contest). There is no way I have copied from anywhere and there is no reason I would provide my solution to someone else whom I don't even know after having already gone through so much of this before. I clearly think it is a case of coincidence that no plagiarism can differentiate between and I believe that MikeMirzayanov will look into this matter.
Edit: Some more details — The user 9thcalamity with whom my solution is coinciding has also submitted 2 Wrong Answer attempts for the same problem which look similar to his coinciding solution. This shows that he has solved the problem on his own otherwise those penalty attempts would not have been there. Moreover, this user seems to be Russian (from his submissions to Russian problems) and I am an Indian. So, there is no way that I know this user.
JaySharma1048576 Stop cheating man.We know you are selling solutions online.
I have never sold solutions to anyone, nor will I ever do so.
High rated user cheating and everyone is taking his side. so sad.
but this time you got what you deserve -293.
You are the foolest and most jealous person I've ever seen! Dumb! Do you think that a high rated person who has cheated and gained much false rating can make a codeforces round? I hope some day, All the dumb people like you get destroyed from the earth!
even C137 was problem setter and was red but he cheated and is banned right now.
Yes even Mehrdad_Sohrabi was a problem setter but he cheated and got banned ...
Ok guys note it down:-
Make a codeforces round and boom you will not be a cheater even though you cheat.
Are you jealous and have something personal against him, or are you really this stupid?
I am not jealous.
Maybe he is not a cheater but i think he uses some other account to avoid penalties.
maybe i am a stupid but getting accused 4 times even in ICPC is not an accident.
Maybe he is not a cheater but i think he uses some other account to avoid penalties.That is exactly what he did, and was called out for, and he admitted to doing so. But that was long back, and I'm pretty sure he doesn't do it anymore. (That account's last visit is 6 months ago, and given that he was called out for it, and now that he has a lowkey reputation in the CP community (having set a few problems on both CC and CF), I find no logical reason why he would do so.)
But this current case is clearly false positive, and you tried to shame him for it, by necro-posting on a blog whose issue was done and dusted months back. I don't understand what motive you would have for it other than personal, and you've been repeatedly trying to accuse him of "cheating", even though anyone with a couple or more brain cells would understand that it clearly isn't.
maybe i am a stupid but getting accused 4 times even in ICPC is not an accident.Learn to read.
If you are really innocent I feel sad for you as you lost a huge amount of rating because getting demoted 2 rank down in a single contest is hard to take mentally.But my question is : Why is it always you???Are you really that unlucky??
False plagrism is not that uncommon.
I am really very unlucky in this regard. The first time it happened was in Codeforces Round 733 because someone leaked my solution from the hacking room and this whole blog is about that.
The second time it happened was during ICPC Amritapuri Online Round where my team was accused of plagiarism but when we mailed them asking them to atleast show us the submissions with whom ours matched, they simply replied that the penalties and the plagiarism mark have been removed and our team has been added to the ranklist and the regionals round without providing any other reasons or details.
This is the third time it is happening because my 10-lines long code for a simple 800-rated problem, where there could hardly be any other solution, coincides with the code of some other user whom I don't even know.
To be honest, I am worried more about having Skipped solutions in my profile rather than being demoted 2 ranks down. There is Codechef SnackDown 2021 Finals on 9th January but as a finalist, my reputation has already gone as low as possible without any fault of mine. I have now even lost my motivation to give any more contests. I used to do CP for fun and interest even after securing a good internship. But now it's not fun at all being accused again and again even when I am not at fault.
From your comment history it's clear that you've been caught for plagiarism on 3-4 different occasions now, which is odd because it's rare for someone who hasn't cheated to get falsely caught once let alone 3-4 times. I don't know if this is just bad luck or it's actually your fault.
Don't want to jump on the bandwagon but, why were all his submissions skipped?
What is the probability of 4-5 consecutive submissions of the same user coinciding with those of some other random users on the same day in the same contest?
Must be exponentially lower than that of the user being really nervous of his performance, and not wanting to lose any rating, first 'testing the waters' with an alt account...
Even if one solution coincides, all the solutions for the contest are skipped. This is usually how it happens. None of my solutions for B, C or D have been accused for coincidence with any other solution.
Are you sure usually this happens. See this. All of his submissions are not skipped . Only ones in which he cheated are skipped. And you are saying that if any solution coincides then all submissions are skipped.
Maybe this is some bug, MikeMirzayanov
Yes man, unfortunately it does happen this way. I have been accused of plagiarism(only for one solution in the entire contest) which happens to be the third problem. Third problem's solutions can coincide man, why does no one get this. Because of that, all my submissions for the contest have been skipped; instead of achieving a 4 digit rating prior to new year from 963, I am down to 859 :( It sucks man. MikeMirzayanov
Are you kidding? You got 'skipped' solutions in 3 out of 13 contests, which is really a lot. The first 2 suspicious contests just became unrated with no negative effect on your rating, but now you got punished for real for the first time.
... says someone, who is currently rated below 1000. I don't think that you have enough contest participation experience to come to this conclusion yet.
Oh, if that is the case, then my apologies.
The chances of Problem A coinciding are pretty high, especially when the solution is so simple.
why were all his submissions skipped?all of the submission is skipped even if 1 problem is plagiarized.i was just thinking why no one does this
if we can move hacking phase after the contest and before system testing then I guess we can avoid this kind of situations.Like 2hrs contest + 1 or 2 hour open hacking phase then system testing
Exactly, I was thinking the same too. And allowing hacks in between contests also gives an unfair advantage to the person whose code gets hacked as compared to the person whose code gets failed on system test due to same mistake, as the person whose code got hacked now knows that there is a problem in his/her code before the contest ends gets an opportunity to resubmit while the other doesn't.
In this case I'd prefer a short hacking phase like in TopCoder (say, 15 minutes). I think many people will not understand to not discuss solutions otherwise.
But it is kinda questionable because most of the time these days, there is not much to hack.
I think just having a long hacking phase and allowing contestants to discuss is fine.