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gyh20's blog

Received a message saying my code of 1517C coincided with someone else's, what should I do?
By gyh20, history, 4 years ago, In English

I took part in the Codeforces round yesterday, and just now I received a message saying my code coincides with someone else's. I didn't know the person at all. I solved the problem a lot earlier than him, and I didn't share my code to anyone or anywhere. I think it's just a coincidence because the solution is short and the code is simple. Could you please take a look into this?MikeMirzayanov

Submissions:113994230 114020895

Could you please reply after seeing this post MikeMirzayanov, thanks!

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

Auto comment: topic has been updated by gyh20 (previous revision, new revision, compare).

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4 years ago, # |
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I have the same doubt... I got this for 1517B. I guess you need to prove it somewhere but I don't know where to. Expecting for a reply on this.

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

    There's a blog of Mike named Rules on Third Party code ( more or less this was the name of the blog ig ) U have to reply in the comments tagging Mike and showing suitable proof .

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      4 years ago, # ^ |
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      Thanks!

      Btw, what can I show to prove that I didn't cheat?

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4 years ago, # |
← Rev. 2   Vote: I like it +64 Vote: I do not like it

I'm absolutely not qualified to make a judgement, just some suggestions here:

  1. Codeforces should make an "appeal" page for complaining the result of cheating detection. On the page it should be shown explicitly that "using ideone or using multiple accounts are not allowed", so we won't see these issues popping up in recent actions (as we can do nothing in fact, only admins can make a final judgement).
  2. I suggest to avoid using some outdated idioms in the code, like register everywhere, and (c << 3) + (c << 1) + v - '0' instead of simply c * 10 + v - '0'. Nowadays most people can't defeat the the compiler on register allocation, and the multiplication-to-shift reduction is done by the compiler automatically (even at -O0). It may be relevent to cheating detection or not: I know this kind of outdated idioms is everywhere in Chinese blogs & high schools, but to others this may look like "some code looking strangely similar".
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    4 years ago, # ^ |
      Vote: I like it +22 Vote: I do not like it

    Yeah, when I looked at submissions, they looked oddly similar, but then I looked at the profile of authors and both being from China, I did think there must be some common Chinese blogs/resources where using the snippet is a common practice.

    Feel for the OP.

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      4 years ago, # ^ |
        Vote: I like it +14 Vote: I do not like it

      Omg, Hi Lohit

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      4 years ago, # ^ |
        Vote: I like it +5 Vote: I do not like it

      It's not a "single" blog or resource. Such idioms are originated in the history (when OI was still using something like Borland C or VC6). Then they are passed through websites, and in high schools from seniors to juniors. Unfortunately only a few people really consider if they are still valid today.

      It seems the OP's rating is restored. Congratulation to him for he is a GM now! But I still suggest him to remove those outdated idiom, though he is a better contestant than me:).

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        4 years ago, # ^ |
          Vote: I like it +3 Vote: I do not like it

        OP was never in danger in the first place, because his solution had been submitted earlier. Of course, unless the system marked him as a potential offender to watch with special scrutiny in the future contests.

        It's actually the other contestant CCCCOrz who got penalized: 114020895.

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4 years ago, # |
← Rev. 3   Vote: I like it +17 Vote: I do not like it

Will I be able to use my template from the next contest(in my main accnt)?
Coz, it contains many GFG functions and I am pretty sure that those functions are very popular to be used by anyone.

P.S — I don't wanna get those messages again & again.

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4 years ago, # |
  Vote: I like it +51 Vote: I do not like it

Suggestion: Implementing overwatch mode like in CS:GO or Dota2. Give high contribution or high rated members the ability to cast vote of whether does a solution is plagiarised.

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    4 years ago, # ^ |
      Vote: I like it -37 Vote: I do not like it

    Probably not just high-rated, because some random LGM could make their own high-rated accounts, and bail themselves out of cheating (not saying they will, but it's a possibility). I think MikeMirzayanov should be able to say "Ok you're trustworthy, you can be one of the voters if you want.".

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      4 years ago, # ^ |
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      Well, first of all, why would a LGM cheat lmao. I know that reaching red through telegram jokes are fun, but dont take them seriously lol.

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        4 years ago, # ^ |
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        https://www.quora.com/Is-there-any-correlation-between-intelligence-and-how-law-abiding-someone-is

        I don't see why several GMs living in the same city can't theoretically cooperate and work as a team to share ideas/solutions during codeforces contests. This would boost their score if that's what they care about.

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          4 years ago, # ^ |
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          I just want to say one thing on this (pasting quora link for obvious reasons)

          https://www.quora.com/Why-are-there-so-many-stupid-humans-in-the-world-on-the-internet

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            4 years ago, # ^ |
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            I'm not saying that you are stupid. But you are surely naive and most likely very young.

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          4 years ago, # ^ |
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          Based on personal deductions , I think ppl who reach GM level have done a ton of practice and generally do CP cuz they enjoy the sport and are good at it, so they are quite unlikely to cheat during a contest .

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            4 years ago, # ^ |
              Vote: I like it +3 Vote: I do not like it

            I fully agree with you. But the key word in your statement is unlikely.

            And not just GM+ people, but even much lower rank holders seem to be quite unlikely to cheat in general. After cheaters purge and rating recalculations for the last two contests, my rating score only increased by a whooping +1 point. The impact of cheating appears to be more or less just in the ballpark of a measurement noise right now.

            Still I believe that the situation may quickly deteriorate if cheating detection gets entirely removed from the platform. And I believe that assuming absolute honesty of all GM/LGM people also would be a mistake. Now you are free to downvote. I'm out of this discussion.

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