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kostka's blog

By kostka, 3 months ago, In English,

Do you need even more Polish problems in your life? This year we are going to organize some contests on our educational platform (Szkopuł) and we decided to open them to the public. All contests will consist of problems from the previous editions of the POI, so you might be quite familiar with them if you ever solved problems on Szkopuł or on MAIN.

First contests (four of them) will imitate the first stage of the POI. Each contest will consist of three problems, last a week (start at 00:00 CEST on Monday, end at 23:59 CEST on Sunday) and have no feedback during the contest (but you have plenty of time to test your submissions). The first contest will start on September the 10th.

How to register? Just create an account on Szkopuł (https://szkopul.edu.pl/) and click on this invitational link: https://szkopul.edu.pl/c/tren18/join/RMQAKCjHhr1ceqVxywNIU5Kv/

Enjoy!

 
 
 
 
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3 months ago, # |
  Vote: I like it +39 Vote: I do not like it

Why no feedback?:((((

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    3 months ago, # ^ |
    Rev. 4   Vote: I like it +19 Vote: I do not like it

    I'm really sorry, but the first stage of the POI tests if one can verify if their solutions are correct and we want to keep this for the trainings as well.

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3 months ago, # |
  Vote: I like it +12 Vote: I do not like it

The first round has started.

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

Why time limit for each problem is unknown?

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    3 months ago, # ^ |
    Rev. 2   Vote: I like it +16 Vote: I do not like it

    This is something I don't get myself, but that's the rule of the POI. I started to lobby that the TL should be published, but we'll see.

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    3 months ago, # ^ |
      Vote: I like it +8 Vote: I do not like it

    Unwritten sad rule of many Polish contests. I don't get why this is the case, but things started getting better. TLs are already published in Algorithmic Engagements which is a brand new thing, hope that his will change on POI as well in near future.

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    3 months ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    Great news, from now on, time limits will be published!

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3 months ago, # |
Rev. 2   Vote: I like it +1 Vote: I do not like it

Wow, in week 1 P1 is much harder than everything else. How to solve P1 (cza) ?

PS: this "feature" of decay points if the solution runs in more than a half of tl is strange, my solution for kin got 100 in szkopul judge but only 66 in the contest. I did nlog(n) with a simple segtree, is intended to do some boring constant optimization or there is a better solution ?

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    3 months ago, # ^ |
      Vote: I like it +18 Vote: I do not like it

    You should think about it as feature of decaying point if the solution runs more than TL and faster than doubled TL ;). I think this is in fact a nice feature, however you will always encounter problems where some submission will be close to TL despite having good complexity.

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      3 months ago, # ^ |
        Vote: I like it +13 Vote: I do not like it

      Ok, I think the time limits for many POI problems are set too strictly if this is the intent.

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

        We try to set limits at least 4*intented solution. Therefore, if someone solves the problem within 2*intended solution limit, then he/she will score full points.