elamharnish's blog

False positive mistake of anti-cheating system

By elamharnish, history, 15 months ago, In English

I've got a letter:

Attention!

Your solution 199960933 for the problem 1810A significantly coincides with solutions hhux/199958881, ElamHarnish/199960933. Such a coincidence is a clear rules violation. Note that unintentional leakage is also a violation. For example, do not use ideone.com with the default settings (public access to your code). If you have conclusive evidence that a coincidence has occurred due to the use of a common source published before the competition, write a comment to post about the round with all the details. More information can be found at http://codeforces.net/blog/entry/8790. Such violation of the rules may be the reason for blocking your account or other penalties. In case of repeated violations, your account may be blocked.

It is just coincidence. It happened that we have similar template with hhux, though we even do not know each other. I'm very sure that there was not code leakage (As I understand my submission was a bit later) It means that anti-cheating system can make mistakes.

I bother about how to write a code in order to avoid such false positive mistakes of the system?

I understand that cheating is a problem, and I want the anti-cheating system to be very accurate. MikeMirzayanov, maybe this case will help to improve it.

  • Vote: I like it
  • +10
  • Vote: I do not like it

»
15 months ago, # |
  Vote: I like it -45 Vote: I do not like it

You have four skipped submissions(A-D)... How did you manage to write the same code 4 times with some other guys?

→ Reply
  • »
    »
    15 months ago, # ^ |
      Vote: I like it +39 Vote: I do not like it

    We do not have the same code for problem B-D. Even in the message of the system it is written that we have similarities in the problem A. May be because of it the whole contest is marked as skipped for me.

    → Reply
    • »
      »
      »
      15 months ago, # ^ |
        Vote: I like it -73 Vote: I do not like it

      I don't think that the system skips all of the submissions if one of them has been skipped.

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

        What is the use not to skip the rest submits in the contest if we suspect that a person is a cheater? I think it skips all submits if one is suspicious.

        → Reply
        • »
          »
          »
          »
          »
          15 months ago, # ^ |
            Vote: I like it -67 Vote: I do not like it

          What if a person cheated on one problem but did the rest by themselves? Skipping all of the submissions would be unfare

          → Reply
      • »
        »
        »
        »
        15 months ago, # ^ |
          Vote: I like it +32 Vote: I do not like it

        If one submission is considered suspicious, all of them are skipped.

        → Reply
      • »
        »
        »
        »
        15 months ago, # ^ |
          Vote: I like it +12 Vote: I do not like it

        dumb aSsss if one solution is found suspicious then all of them are skipped

        → Reply
  • »
    »
    15 months ago, # ^ |
      Vote: I like it +27 Vote: I do not like it

    I did not check but you can compare if you do not believe me. I claim that I have never cheated.

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

      Your solution to problem A is very small and simple, a lot of people could come up with the same code. So I think that's the system's mistake.

      → Reply
»
15 months ago, # |
  Vote: I like it +11 Vote: I do not like it

At least please give me advice what should I do to avoid false positive errors? Should I switch to a less common programming language or any other suggestions?

→ Reply
  • »
    »
    15 months ago, # ^ |
      Vote: I like it +9 Vote: I do not like it

    Mike (or other admins) usually checks blog likes this manually and revert the false positives. You don't really have to do anything against it so don't worry about it.

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

MikeMirzayanov, at least please let me know that you do not consider me as a cheater.

→ Reply