DanceTheTragonDrainer's blog

Problem Setter Revealed!!! (Indian ICPC 2019)
By DanceTheTragonDrainer, 5 years ago, In English

The ranklist is out and they haven't deleted this problem. Can anyone post the correct solution to this problem?

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5 years ago, # |
  Vote: I like it -25 Vote: I do not like it

Codechef sucks, fuck ICPC, fuck CP. It's all about IQ anyways, no matter how much you practice, you cannot outperform your IQ.

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    5 years ago, # ^ |
      Vote: I like it +120 Vote: I do not like it

    IQ is a meme and you'll become one too if you keep writing dumb shit like this. You can always perform better.

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5 years ago, # |
  Vote: I like it +39 Vote: I do not like it

I wouldn't specifically target the problem setter, as a lot of people thought about the solution along the same (incorrect!) lines during testing as well as during the contest — this was the fifth-most solved problem, after all. What I don't understand is what CodeChef is doing about it: https://discuss.codechef.com/t/icpc-india-regionals-online-round-2019-updates/42035

Are they masking an incorrect problem as one of the "issues" reported by a few "participants"? There is a fair chance that the regional directors completely ignore it and accept the ranklist as is.

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

    exactly :(

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    5 years ago, # ^ |
    ← Rev. 2   Vote: I like it +20 Vote: I do not like it

    They could have followed a simple startegy "If you cannot prove your greedy, don't make the problem". Doesn't matter what contestants thought. It's a high pressure situation and most teams would "submit and think" rather than "think and submit" especially when there are other problems to focus on.

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5 years ago, # |
← Rev. 2   Vote: I like it +10 Vote: I do not like it

Such a "Click-Bait"! XD

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5 years ago, # |
  Vote: I like it +133 Vote: I do not like it

If you think about lynching the guy, don't.

When a faulty task appears (especially on an important contest), it's never one man's fault. The guy probably invented an incorrect solution (which happens), but then nobody stressed the solution with a provable brute-force solution, nobody asked for a formal proof of correctness... probably no organizer even thought of doing this. It's usually procedures that fail.

There might be a reason some bad stuff like this happens quite frequently on Codechef.

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    5 years ago, # ^ |
      Vote: I like it +12 Vote: I do not like it

    No one is holding the guy responsible, it's about Codechef not doing the right thing which is to simply delete the problem and the corresponding score from the official ranklist.

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    5 years ago, # ^ |
      Vote: I like it +45 Vote: I do not like it

    Stresstesting is the reason. The problem with asking for a formal proof is that many people can't write a formal proof, so you get an informal one that omits something essential... then you have to work your way through it slowly or you'll miss it too. See problem Skyscrapers at CEOI, I spent a shitload of time on understanding why the proof works, only to end up concluding that it doesn't and changing the problem so it would. In problems like this one, though, it would be fairly easy to catch mistakes just by stresstesting.

    CC testing practices are mostly writing a solution, briefly checking if the author's makes sense, validating I/O and making up some wrong solutions that shouldn't pass (but rarely in an elaborate way). It's less detailed than on CF because there's just one tester, too.

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5 years ago, # |
  Vote: I like it +12 Vote: I do not like it

They said to wait for the further announcement. So just wait. I was the guy who opened that problem and wasted all 3 hours doing the same shit. My teammates are cursing me now. So just chill.

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