xay5421_killer's blog

Maybe xay5421 cheats in contests
By xay5421_killer, history, 2 years ago, In English

Maybe it's just a coincide.If I do wrong,sorry for it.

Hey guys!I find something strange in the last contest.xay5421 solved E in 10 mins.

When I see his code, I find:

// author: xay5421 // created: Fri Nov 12 14:55:34 2021

The created time is very strange,you can see the difference: (problem B):

// author: xay5421 // created: Sun Nov 14 14:09:02 2021

And then, I also notice his code of D:

// author: xay5421 // created: Fri Nov 12 14:20:34 2021

Very strange,right?It seems someone is manage to help with him,but he/she forgets to modify the created time.

Then,I search past contests and find something even more strange:

  • in CF1601,D 0:59,E 1:09.
  • in CF1586,his code of G is tab with 8 spaces,but other codes is tab with 4 spaces.How did he do that?
  • in CF1553,E 1:07,I 1:20,H 1:47,G 2:24, F 2:29. Is he a superman?
  • in CF1545,he submits a Compilation Error code.link.U can see "#include<bits/甩头dc++.h>" in this code.

And also,raingirl, xuanyi are his accounts(maybe more).Why does xay5421 use so many accounts?

As a participant,I'm coufused how does he do that.Is there any LGM help him to make it?

  • Vote: I like it
  • +322
  • Vote: I do not like it

Comments Comments (54)
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2 years ago, # |
  Vote: I like it +16 Vote: I do not like it

Just one advice. If you suspect that anyone is cheating. Instead of writing blog you should email codeforces about it. I reported 2 participants in codechef.

Btw,Its little suspicious and MikeMirzayanov should focus on it. Or it can be just some technical error and xay5421 sould clarify it.

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2 years ago, # |
  Vote: I like it +77 Vote: I do not like it

For the timing, I think it's pretty normal for higher rated people to read through all the problems, then jump around the problems and attempt on problems they can solve right away. In case that attempt fails, they can jump to other problems then solve them, then come back later. They don't just try to solve everything in the given order in the contest.

For the CE, it could be just the Chinese typing method auto completion messing up.

For the switch from spaces to tabs (yes, it's spaces to tabs, so in most editors they will look the same), it happened when he used the modular template. This could be from an already existing file, like (you name it) codes from other people, or perhaps just old codes (say, with his old coding style?). Another theory is that the template could be written with 4 spaces, and it might remain 4 spaces for the rest of the code if he extended the code from this part.

I don't have the intension of defending xay5421. However, I personally think everything in the blog can be justified, without cheating involved. Definitely an interesting case.

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2 years ago, # |
  Vote: I like it +194 Vote: I do not like it

in CF1545,he submits a Compilation Error code.link.U can see "#include<bits/甩头dc++.h>" in this code.

very suspicious indeed

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    2 years ago, # ^ |
      Vote: I like it +188 Vote: I do not like it

    When using a communications software in China called QQ, /st will be transformed into /甩头, which is a type of emoji. It seems that he use QQ to copy others code even without compiling.

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2 years ago, # |
  Vote: I like it +55 Vote: I do not like it

Takeaway: don't use cringe template and macros.

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2 years ago, # |
  Vote: I like it -42 Vote: I do not like it

If he is cheating then he is a very advanced level cheater.

I think we should encourage such talented people.

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    2 years ago, # ^ |
      Vote: I like it -22 Vote: I do not like it

    So you are basically promoting cheating. Not long from now there will be more cheaters of this level (Only if he is actually cheating). And they will be higher rated than you. I wonder what say you'll have then

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      2 years ago, # ^ |
        Vote: I like it -40 Vote: I do not like it

      I'm not promoting cheaters, I'm promoting the best (potential) cheater (one and only one) in the world.

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    2 years ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    I think we should encourage such talented people.

    It isn't "talent", but more like amazing "teamwork" and the "power of friendship". And also the "courage" to dismiss the rules of the "evil system". Their "selfish" and "individualistic" adversaries can be defeated! At least as long as contests are done in online format.

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      2 years ago, # ^ |
      ← Rev. 2   Vote: I like it 0 Vote: I do not like it

      Basically what shounens preach.

      looks at xay5421 and raingirl's pfp

      Go figure

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2 years ago, # |
  Vote: I like it +154 Vote: I do not like it

Is he a superman?

Yes

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    2 years ago, # ^ |
      Vote: I like it +53 Vote: I do not like it

    Maybe 'he' is not a superman, but 'they' are a group of supermen. XD

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2 years ago, # |
  Vote: I like it +132 Vote: I do not like it

Not attacking or defending here, but just saying that a possible cause for having the creation time and date not match its submission time might be excusable; I regularly copy old files to reuse some template code, and I can easily see myself copying that date by accident.

The differing indent sizes is very suspicious though... If multiple people were participating under one account, this is a likely thing to see.

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2 years ago, # |
← Rev. 2   Vote: I like it +191 Vote: I do not like it

When Chinese use Tencent QQ to send codes, /st will be transformed to /甩头.

Because /st is the emoji

So I guess he used Tencent QQ to copy codes from others.

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    2 years ago, # ^ |
      Vote: I like it +78 Vote: I do not like it

    fun fact：I have tried to use qq to reply '#include <bits/stdc++.h>','/st' disappeared but not became '/甩头'

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      2 years ago, # ^ |
        Vote: I like it +91 Vote: I do not like it

      Maybe he use some special mode,that can make /st become /甩头 instead of that emoji.

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      2 years ago, # ^ |
        Vote: I like it +115 Vote: I do not like it

      I think that's because the version of Tencent QQ is different between us.

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2 years ago, # |
  Vote: I like it +93 Vote: I do not like it

One For All,All For One

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2 years ago, # |
  Vote: I like it +65 Vote: I do not like it

Interestingly,the last contest cheater Alan233 is in the same school with xay5421.Alan233 got rank#8 with cheating in the last contest and it seems that it was not the first time that he cheated in the codeforces.

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    2 years ago, # ^ |
      Vote: I like it +183 Vote: I do not like it

    Well, I'm pretty sorry for my fault :(

    But I also want to say I don't communicate with xay5421, so this event is none of my business.

    #include <bits/甩头dc++.h> means he copies code from Tencent QQ (and without compiling), so I guess probably somebody writes codes and send them to xay5421, and the other person doesn't participate in the contest.

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    2 years ago, # ^ |
    ← Rev. 2   Vote: I like it +30 Vote: I do not like it

    Alan233 has nothing to do with xay5421.

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2 years ago, # |
  Vote: I like it +187 Vote: I do not like it

Team-work

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2 years ago, # |
  Vote: I like it +21 Vote: I do not like it
  • in CF1553 he is the first to solve I
  • in CF1586 he is the first to solve G
  • in CF1601 ,C 0:59,D 1:09,but he has submitted D several times before
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2 years ago, # |
  Vote: I like it +5 Vote: I do not like it

How do you know raingirl is xay5421's accounts?

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    2 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Because you can found 

    // author: xay5421
// created: *** *** ** **:**:** ****

    in raingirl's code

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      2 years ago, # ^ |
      ← Rev. 2   Vote: I like it -37 Vote: I do not like it

      I mean how could he find raingirl?

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        2 years ago, # ^ |
          Vote: I like it +74 Vote: I do not like it

        Perhaps he actually knows xay5421 and all xay5421's accounts in real life, and is angry about xay5421's cheating.

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        2 years ago, # ^ |
        ← Rev. 2   Vote: I like it -9 Vote: I do not like it

        You can find it here, it's also where I know that.

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2 years ago, # |
  Vote: I like it +7 Vote: I do not like it

Hangzhou, in China, is called "a place where the national training team can't enter the provincial team (to represent the province in national competitions)".

And he comes from a strong school, so Superman exists in Hangzhou. There is no doubt!

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2 years ago, # |
  Vote: I like it -40 Vote: I do not like it

This might be cheat —— I thought more than 95%

But is it really matter you?

And I think it is common for a people to use several accounts?

Just my thought.

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    2 years ago, # ^ |
      Vote: I like it +82 Vote: I do not like it

    I have nothing against using several accounts.

    But cheating is not fair to other participants.

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    2 years ago, # ^ |
      Vote: I like it +228 Vote: I do not like it

    Only my opinion, maybe a bit unrelated, and I don't want to show offense to anyone.

    Take Alan233 mentioned above as an example. Before being removed as a cheater, his rank was better than mine. And even one place matters much in first 100 ranks in Div1 you know.

    I once saw a blue comment (sorry that I forgot the link) with the main meaning "Stop caring about these things. Most of the cheaters are below blue, and if you are purple or above you won't get much affected, so just go and practice". Well I was shocked by this idea at that time and treated it as an absolute truth.

    And now such cheating happens in front of me, it does matter me.

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    2 years ago, # ^ |
      Vote: I like it +24 Vote: I do not like it

    I always see my friends' rating gain more after anti-cheating.

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    2 years ago, # ^ |
      Vote: I like it +20 Vote: I do not like it

    I'm sorry for my unknown of high-raters' competition and bad mood shown in the comment.

    Because I thought a lot of people's purpose for cheating is for fun.

    I never thought it could make such influence.

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2 years ago, # |
  Vote: I like it -39 Vote: I do not like it

Codeforces is going to be cheatforces.

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    2 years ago, # ^ |
      Vote: I like it -31 Vote: I do not like it

    Cheating does have a bad effect on codeForces. Anti-cheating always needs to be continued.

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2 years ago, # |
← Rev. 2   Vote: I like it +8 Vote: I do not like it

.

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2 years ago, # |
  Vote: I like it +13 Vote: I do not like it

I know that some schools have an account for all the OIers of the school. They sometimes do the problems at the same time. For example,the OIer A does problem A the OIer B does problem B,etc. Perhaps,this is the reason.

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2 years ago, # |
  Vote: I like it +49 Vote: I do not like it

Hope MikeMirzayanov can ban xay5421 as soon as possible

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2 years ago, # |
  Vote: I like it 0 Vote: I do not like it

I do not know if he is a cheater, but it is not easy to solve problem E in 10 minutes.

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2 years ago, # |
← Rev. 2   Vote: I like it +1 Vote: I do not like it

Innocent until proven guilty.

It seems inproper before the truth appears.

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2 years ago, # |
  Vote: I like it +60 Vote: I do not like it

Reasons why you shouldn't include bits/stdc++.h:

  1. it makes your local compilation slower

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2 years ago, # |
  Vote: I like it +9 Vote: I do not like it

“甩头” is a word in Chinese, and this is a feature in QQ.

Maybe they talk in QQ.

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2 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

--DELETED--

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2 years ago, # |
  Vote: I like it -21 Vote: I do not like it

No action taken even after 4 days...

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