xay5421_killer's blog

By xay5421_killer, history, 2 months 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?

 
 
 
 
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2 months ago, # |
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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 months ago, # |
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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 months ago, # |
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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 months ago, # ^ |
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    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 months ago, # ^ |
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      This is true, but why use QQ? Know everything

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2 months ago, # |
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Ban all chinese coders on codeforces.

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    2 months ago, # ^ |
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    Ban everybody and there will be 0 cheaters. And 0 people. So the ratio will be 0/0.

    wait. I just divided by zero

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    2 months ago, # ^ |
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    Funny Mud Pee.

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2 months ago, # |
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Takeaway: don't use cringe template and macros.

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    2 months ago, # ^ |
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    can u explain all those compilation error submissions????

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2 months ago, # |
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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 months ago, # ^ |
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    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 months ago, # ^ |
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      I'm not promoting cheaters, I'm promoting the best (potential) cheater (one and only one) in the world.

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    2 months ago, # ^ |
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    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 months ago, # ^ |
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      Basically what shounens preach.

      looks at xay5421 and raingirl's pfp

      Go figure

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2 months ago, # |
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Is he a superman?

Yes

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    2 months ago, # ^ |
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    Maybe 'he' is not a superman, but 'they' are a group of supermen. XD

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2 months ago, # |
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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 months ago, # |
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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 months ago, # ^ |
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    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 months ago, # ^ |
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      Maybe he use some special mode,that can make /st become /甩头 instead of that emoji.

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      2 months ago, # ^ |
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      I think that's because the version of Tencent QQ is different between us.

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    2 months ago, # ^ |
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    Maybe he is writing codes in QQ, what you say!

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    2 months ago, # ^ |
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    absolutely, "st" is the intial of this "shuai tou" emoji.

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2 months ago, # |
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One For All,All For One

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2 months ago, # |
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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 months ago, # ^ |
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    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 months ago, # ^ |
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    Alan233 has nothing to do with xay5421.

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2 months ago, # |
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Team-work

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2 months ago, # |
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  • 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 months ago, # |
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How do you know raingirl is xay5421's accounts?

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    2 months ago, # ^ |
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    Because you can found

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

    in raingirl's code

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      2 months ago, # ^ |
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      I mean how could he find raingirl?

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        2 months ago, # ^ |
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        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 months ago, # ^ |
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        You can find it here, it's also where I know that.

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2 months ago, # |
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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 months ago, # |
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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 months ago, # ^ |
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    I have nothing against using several accounts.

    But cheating is not fair to other participants.

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    2 months ago, # ^ |
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    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 months ago, # ^ |
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    I always see my friends' rating gain more after anti-cheating.

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    2 months ago, # ^ |
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    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 months ago, # |
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Codeforces is going to be cheatforces.

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    2 months ago, # ^ |
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    Cheating does have a bad effect on codeForces. Anti-cheating always needs to be continued.

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2 months ago, # |
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.

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2 months ago, # |
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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 months ago, # |
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Hope MikeMirzayanov can ban xay5421 as soon as possible

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2 months ago, # |
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Why does xay5421 use so many accounts? many div1 participants have alt accounts ask them why? :D and also ko_osaga solved problem E of the last contest in around 9 minutes so it's not suspicious that he solved this problem 10 minutes after B. But other details you said are suspicious!

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2 months ago, # |
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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 months ago, # |
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Innocent until proven guilty.

It seems inproper before the truth appears.

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2 months ago, # |
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raingirl got rank 1 in CF round 695 div2, maybe xay5421 used to participate in div2 using this account!

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2 months ago, # |
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Reasons why you shouldn't include bits/stdc++.h:

  1. it makes your local compilation slower

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2 months ago, # |
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“甩头” is a word in Chinese, and this is a feature in QQ.

Maybe they talk in QQ.

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2 months ago, # |
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I'm a dragon

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2 months ago, # |
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No action taken even after 4 days...

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2 months ago, # |
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wonder how much time it must've taken noting and writing such minute details