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fbrunodr's blog

East Asian bias on today's contest
By fbrunodr, history, 19 months ago, In English

Problem E appeared on Honk Kong online judge

Honk Kong Online Judge

Although the intended solution is O(n^2), the editorial provides a O(n) solution, as can be seen here: 2022 Mini Competition 3 Editorial

You can't have access to this site unless someone from your school paid the Hong Kong judge and registered you.

Problem H appeared ipsis litteris on a Japanese online judge

This one has already been discussed by the contest author: https://codeforces.me/blog/entry/142069.

Imagine if a Brazilian made the hardest problem equal to a problem only available on a Brazilian online judge (which is also Portuguese only) and problem E appeared on a Latin American training list. This would hugely favor Brazilians / latin Americans and be unfair to everyone else. Well, if you guys decide to make this contest rated, don't do different if the scenario I just described happens.

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19 months ago, hide # |
 
Vote: I like it +14 Vote: I do not like it

the difference is intention.

The author has even submitted proof that he did not do it intentionally. There is nothing more he could have done.

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    19 months ago, hide # ^ |
     
    Vote: I like it -30 Vote: I do not like it

    Intention does not remove the bias.

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      19 months ago, hide # ^ |
       
      Vote: I like it -7 Vote: I do not like it

      Bias cancels out itself if you participate enough

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      19 months ago, hide # ^ |
       
      Vote: I like it -6 Vote: I do not like it

      And? How does "japanese have seen it" differ from "this subset of people from various countries have seen it"??

      Several times the site has been luogo instead with chinese having an advantage.

      Its still "unfair" to the contestants, and in a perfect world we would not have either.

      But, its well documented by now with the 1e9 + 7 problem coincidences that happen — problem coincidences are not a reason to unrate. I dont see how a specific region performing better is reason to change that.

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      19 months ago, hide # ^ |
       
      Vote: I like it +45 Vote: I do not like it

      bro will say every algorithm problem has bias for Chinese participants because they know it all

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19 months ago, hide # |
 
Vote: I like it +8 Vote: I do not like it

Imagine if a Brazilian made the hardest problem equal to a problem only available on a Brazilian online judge (which is also Portuguese only) and problem E appeared on a Latin American training list. This would hugely favor Brazilians / latin Americans and be unfair to everyone else. Well, if you guys decide to make this contest rated, don't do different if the scenario I just described happens.

The scenario you described already happened and nobody complained about a brazilian bias: On round 959 there was a problem which appeared not once but twice on a brazilian contest.

Not to mention that the authors are not from Hong Kong or Japan, so I don't know what you're smoking with that analogy. Do you think that they intentionally did problems in such a way that would benefit "East Asia"? If they didn't do it intentionally, how would you prevent the contests from being "biased"?

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    19 months ago, hide # ^ |
     
    Vote: I like it 0 Vote: I do not like it

    I never said the author did anything intentionally, I said there was a clear bias and thus we should consider making the contest unrated.

    If they didn't do it intentionally, how would you prevent the contests from being "biased"?

    You can’t prevent in the case it is unintentional, but you could still make contests that are clearly biased unrated.

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