Mystairous's blog

Cheating in Codeforces 938 Div3 Contest
By Mystairous, 8 months ago, In English

Dear Contest Authors and Coordinators (Vladosiya, mainyutin, ssor96, vmanosin7, ZergTricky),

I am writing to bring to your attention a concerning observation regarding the submissions for Problem D in Codeforces 938 Div3 Contest. Upon reviewing several submissions, it has come to my attention that a significant portion of them appear to be identical or highly similar.

I urge the contest authors and coordinators to conduct a thorough investigation into this matter and take appropriate action if code plagiarism is found to have occurred. Preserving the integrity of programming contests is crucial for maintaining a fair and competitive environment for all participants.

Below are links to some of the submissions in question:

https://codeforces.me/contest/1955/submission/255677438

https://codeforces.me/contest/1955/submission/255719237

https://codeforces.me/contest/1955/submission/255699876

https://codeforces.me/contest/1955/submission/255704053

https://codeforces.me/contest/1955/submission/255668552

https://codeforces.me/contest/1955/submission/255686490

UPD:

https://codeforces.me/contest/1955/submission/255743345

https://codeforces.me/contest/1955/submission/255721307

Check out these two submissions as well. They both have the same solution for problem E in the same contest.

Youtube: https://www.youtube.com/watch?v=L08Rksge2v4

See this as well. This guy has been streaming solutions for the contest. So I think some of the guy would have seen this during contest and then used the exact same solution.

Your prompt attention to this matter is greatly appreciated.

Thank you for your cooperation.

  • Vote: I like it
  • +20
  • Vote: I do not like it

»
8 months ago, # |
  Vote: I like it +1 Vote: I do not like it

There must be a telegram group or something from which they must be cheating. This makes the the participants feel demotivated when they don't get a good rank even after giving their best without copying solutions from others.

→ Reply
  • »
    »
    8 months ago, # ^ |
      Vote: I like it +10 Vote: I do not like it

    There must be a telegram group or something from which they must be cheating.

    Of course, there is.

    This makes the the participants feel demotivated

    I really don't understand why. Instead of looking on the numbers (ex. 1351, 1511 and so on), look on your delta (+100 rating in three months). This way you will understand, how fast are you progressing, and won't be demotivated by your rating. No matter how many cheaters are there in any contest, the better you perform, more rating you get.

    → Reply
  • »
    »
    8 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    But one of the submissions below, there have one guy, who ranked 17th place in last div 3. I think he is not a cheater

    → Reply
»
8 months ago, # |
  Vote: I like it 0 Vote: I do not like it

lol the task is pretty simple so of course some of 6500 submissions can be similar

→ Reply
  • »
    »
    8 months ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    The increment and decrement signs including rest all statements match in https://codeforces.me/contest/1955/submission/255677438 and https://codeforces.me/contest/1955/submission/255699876 . This cannot happen no matter how many solutions there are.

    Just variables have been changed.

    → Reply
    • »
      »
      »
      8 months ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      But the overall task itself is just window sliding which can have a lot of similarities in code. Looking at the solutions right now, there are many submissions similar to the one you mentioned. Take for example: 255669355

      The person does not have this rated since he is >1600 but the code and implementation is similar if not the same as the ones you mentioned above. I understand that cheating is a big concern but if the implementation itself is simple, similarities are bound to happen

      → Reply
»
8 months ago, # |
  Vote: I like it +2 Vote: I do not like it

Wow! Live streamed [A...F]

→ Reply
»
8 months ago, # |
  Vote: I like it +1 Vote: I do not like it

The user in the first submission has been cheating regularly but is using different techniques to avoid plagiarism. Just look at this submission of CF 916 Div3.

https://codeforces.me/contest/1914/submission/238021607

In this, he has written one code and then used it again and again and he kept clearing set in between. In this way he escaped plagiarism checker.

→ Reply
»
8 months ago, # |
  Vote: I like it +2 Vote: I do not like it

Aliyyiakbar — A and hasanovr — H also cheated.

Here are the submissions: ( I don't think these guys coincide by chance . 3+ times...)

→ Reply
  • »
    »
    8 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    LoL woakslksksjskaka

    → Reply
  • »
    »
    8 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    On problem G, I used a simple approach of storing all possible GCD values till i-th row and j-th column. This will MLE, so I used to store only the distinct values to speed-up the code. This DP technique is often taught by most known algorithm mentors and teachers in Azerbaijan. I don't see any coincidence here, since it's a straightforward idea and is hacked for a reason I still don't understand (heap-memory allocation isn't cheap operation maybe?).

    Rest problems are math and simple implementation.

    hasanovr is a good friend of mine. Has been doing competitive programming for years and calling both of us "cheated" for intermediate level problems that you can't comprehend is the evidence how fool and loser you are.

    We will find you in ARIO Finals, or did you even qualify to Finals?

    → Reply
    • »
      »
      »
      8 months ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      You are alone wolf my brother.

      → Reply
    • »
      »
      »
      8 months ago, # ^ |
      ← Rev. 2   Vote: I like it +4 Vote: I do not like it

      I hate dramas. My contribution hasn't even changed (alt's downvote not affecting). I didn't say the problems are hard. They are for div3 level.

      We will find you in ARIO Finals, or did you even qualify to Finals? I won't be at tg cheater channels.

      After Aliyyiakbar realized I will expose him:

      yes
      → Reply
      • »
        »
        »
        »
        8 months ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        You really enjoy dramas, don't you? I'm not scared of them.

        You think you're clever, huh? How did you find this channel so fast?

        You fell for my decoy message and now you think you've caught me, right?

        Nice work, Mr. Sherlock. Now it's my turn to reveal your two years of skipped account history and your cheater friends who can't even get good at programming and spread hate using you as a pawn.

        → Reply
      • »
        »
        »
        »
        8 months ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        What kind of group is that? If it's illegal how did you find it? I think you're the one who is random hater or you have some personal issues with him. Blaming someone is not good behaviour.

        → Reply
        • »
          »
          »
          »
          »
          8 months ago, # ^ |
          ← Rev. 4   Vote: I like it +3 Vote: I do not like it

          Hello Mr. Alt. Since the group has a 9k members it is pretty easy to find it. I don't think TheScrasse needs cheater tg groups, but seems like he is also aware of this group.

          ss
          → Reply
»
8 months ago, # |
  Vote: I like it 0 Vote: I do not like it

Sending some online webinar is not enough! I need clear straightforward information! Imagine yourself in such situation relaying on some random gaming is stupid

→ Reply
»
8 months ago, # |
  Vote: I like it 0 Vote: I do not like it

The submissions look different.

→ Reply
»
8 months ago, # |
  Vote: I like it +1 Vote: I do not like it

it seems that you are just posting it to gain upvotes.

→ Reply
»
8 months ago, # |
  Vote: I like it 0 Vote: I do not like it

what do the lil bro gain from doing this?

→ Reply