ipaljak's blog

Croatian Olympiad in Informatics (COI) 2021
By ipaljak, history, 3 years ago, In English

Hi all,

Croatian Olympiad in Informatics (COI) represents the first major step towards forming the Croatian IOI team. As you know, we usually hold an online mirror of this contest as the last round of the COCI season.

On that note, I'm happy to invite you to join us on Sunday, April 25, starting at 14:00 (GMT/UTC). The contest will feature 3 to 5 IOI-style tasks and it will last for 5 hours. You will also have full feedback with at most 50 submissions per task.

You can access the judging system here. The registration period ends 1 hour before the beginning of the contest (look it up under "Events").

Hope you'll enjoy the contest.

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3 years ago, # |
  Vote: I like it +68 Vote: I do not like it

This is at exact same time as BOI day2 mirror.Can the timing or date of COI mirror be changed?

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3 years ago, # |
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Where can I find the problems for upsolving?(since I didn't take part in the contest as I was giving BOI day2)

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    3 years ago, # ^ |
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    You can find them in the task archive under "Srednje škole / 2021. / 4. HIO"

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3 years ago, # |
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How does your checker for MalnaRISC work? I thought this verifying the validity of such a network was co-NP complete, so verifying it seems computationally infeasible. Or, is the wording of the problem such that the network only needs to sort some secret hidden permutation?

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    3 years ago, # ^ |
    ← Rev. 2   Vote: I like it +8 Vote: I do not like it

    For small arrays, it checks all 2^n bitstrings. For large arrays, it checks if the solution works on ~10k of arrays generated from various distributions.

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3 years ago, # |
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Will there be an editorial at some point?, after a few days https://hsin.hr/coci/ was updated but there is no editorial.

I know it's been a while since the contest, but can someone explain how to solve B? (I only know how to do it in N^3)

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3 years ago, # |
  Vote: I like it +11 Vote: I do not like it

You can solve all problems here: https://oj.uz/problems/source/556

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