ko_osaga's blog

XXII Open Cup. Grand Prix of Daejeon
By ko_osaga, history, 3 years ago, In English

Hello!

XXII Open Cup. Grand Prix of Daejeon will be held in 2022/03/27 Sunday, 17:00 KST (UTC+9). The date of March 27 is final.

Daejeon is home to KAIST, but the contest itself has little to do with it, it just inherits the spirit of 2019 Daejeon GP.

The contest was used as a Day 2 Contest for Petrozavodsk Winter Camp 2022. I'm sorry for the camp participants over the lack of editorial. I will work to publish the full editorials right after the GP.

Problems were authored by ko_osaga, GyojunYoun, tamref, Diuven, queued_q, jh05013. Special thanks to xiaowuc1 for reviewing the statements.

For external accounts, the contest is ready now.

Note that the old opencup.ru link is not accessible now. (snarknews is trying to find servers outside of Russia.)

List of relevant previous contests:

Enjoy!

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Comments Comments (21)
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3 years ago, # |
  Vote: I like it +65 Vote: I do not like it

As a camp participant, I really love this contest. It's my favourite contest in the Winter Petrozavodsk Camp.

Spoiler
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    3 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Agree! I found those problems really interesting even I tended to dislike a round with many data structure problems.

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

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

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3 years ago, # |
  Vote: I like it +75 Vote: I do not like it

Due to the Russian invasion of Ukraine, the contest is postponed for a week.

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3 years ago, # |
  Vote: I like it +34 Vote: I do not like it

If the Opencup round really is tomorrow, it seems it conflicts with the Codeforces div. 1 round. Is this really the case?

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

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

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3 years ago, # |
  Vote: I like it +3 Vote: I do not like it
One symbol typo
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3 years ago, # |
  Vote: I like it +34 Vote: I do not like it

Seems the contest has (finally) been finished.

What's the idea behind problem G? Is it related to some new techniques?

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3 years ago, # |
  Vote: I like it +21 Vote: I do not like it

Thank you for the participation. Editorials are here. Gym contests will be configured shortly.

Authors:

and kudos for MIT_Copypaste who prevented D to survive through Prime Contest. (Big surprise for me!)

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3 years ago, # |
  Vote: I like it +16 Vote: I do not like it

Gym (Ghosts are unavailable due to the closing of opencup.ru)

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    3 years ago, # ^ |
      Vote: I like it +21 Vote: I do not like it

    Gym's built-in parser works well for the Yandex.Contest standings page... Maybe you can add ghosts by parsing the standings page directly.

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

      Hmm... which things should I copy-paste? I tried several stuffs but none of them worked

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        3 years ago, # ^ |
        ← Rev. 2   Vote: I like it +21 Vote: I do not like it

        Just copy the whole table in HTML to the parser. I have set it up by using the built-in parser and the standings data from Yandex.Contest.

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          3 years ago, # ^ |
          ← Rev. 2   Vote: I like it 0 Vote: I do not like it

          I really don't get it. If I download the HTML of standing page, I receive a 1MB-size text. Sorry, I'm bad at machines...

          EDIT: Ok you have set it up already, thank you XD

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3 years ago, # |
  Vote: I like it +25 Vote: I do not like it

Is problem J just intended to be a massive augmented top tree? I have a top tree with a dozen different pieces of augmenting information and a 120 line update() function.

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

    Unfortunately yes. However Marcin_smu upsolved it with link cut tree (it was not easier, but we don't have top trees)

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3 years ago, # |
  Vote: I like it +30 Vote: I do not like it

I already nominate K (Fake Plastic Trees 2) as the best problem of the year

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

I have stuied the editorial of problem I for hours and got the idea of the $$$\mathcal O(q^2 + (n + q) \log^2 n)$$$ solution but I can't understand the d&c part in the editorial at all. Can anyone explain this in detail? thanks.

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