Um_nik's blog

By Um_nik, history, 3 hours ago, In English
  1. How does hacking work with the new feature of unrated registration? I have seen this question raised in the comments to the announcement several times, but there is no answer still and I think it's weird that Mike hasn't thought about it before announcing.

  2. I was working recently on a div.2 Codeforces round (still might happen in the future) and I was told by my coordinator that pretests should be equal to systests in all the problems. From this I can conclude that it is a Codeforces policy and intentionally weak pretests do not happen. It doesn't mean that it is impossible to hack anybody, but it doesn't sound like a viable strategy. I find it weird that this information is not public, it's like I'm getting bonus information about all other Codeforces rounds by setting a round myself.

I have done exactly zero research on the matter, but my feeling is that 99% of hacks (I'm talking about during-the-round-hacking here, not open hacking of education rounds and such) happen in rare cases when authors didn't break some popular for some reason wrong solution, and every room has (15+-3) solutions with the same bug. So somebody in the room gets (1500+-300) points that have no correlation with their problem-solving skill, and even if somehow it is the top participant in the room, it still can affect the results in a random way due to rooms. It doesn't feel good to win a round like this. It feels even worse to lose a round in such a way.

I would be glad if during-the-round-hacking was removed.

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2 hours ago, # |
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Strong agree. Hacking was during Topcoder days when pretests were weak/nonexistent, and with room-based rounds. Modern codeforces rounds have strong pretests and systests, so hacks are basically only by tryhards to cancel div3/4 solutions using a dict in python. I support this feature being removed during the round.

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112 minutes ago, # |
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I totally agree. And while we are at it, another feature request would be to enforce rating recalculation for everyone who is registered as rated for the round. Imagine someone opens problems, can't solve anything, doesn't make a submit and there's no penalty for that. Such pussy behaviour should not be tolerated. Topcoder had it, Atcoder has it, this is the way.

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    96 minutes ago, # ^ |
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    Don't agree with this — what if you register but then have an emergency which means you can't participate...

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      76 minutes ago, # ^ |
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      Register immediately before the round

      Making stuff hard to take advantage of is much more important than accounting for such people.

      I have never missed a rated atcoder round that i registered for.

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        74 minutes ago, # ^ |
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        but this isn't possible because of that braindead 5 minute period before the round where you can't register

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          71 minute(s) ago, # ^ |
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          That would go away if hacking got removed fyi (since no need of rooms)

          Either way, is it too much effort to sit down 10mins before a contest?

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      74 minutes ago, # ^ |
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      Register when you know you are capable of attempting the contest, as of me I always find myself before 10-15 minutes in front of my PC before a round and we have the option to register before 10-15 minutes so better register then.

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    63 minutes ago, # ^ |
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    strongly agree very unethical

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63 minutes ago, # |
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Hi! We're making progress on this issue. Don't go too far, and you'll see changes soon.

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    61 minute(s) ago, # ^ |
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    Kindly look at the above request too.

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    13 minutes ago, # ^ |
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    What do you think about all rounds having hacking, but strictly after the round, like in div3/4? That way, the potential for cheats stealing innocent people's solutions and putting them on Telegram is removed

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    5 minutes ago, # ^ |
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    Please don't remove systest phase