oleh1421's blog

By oleh1421, history, 13 months ago, In English

EJOI 2021 — the first competition, where I have been a part of our national team NOT as a contestant. This post is written for one reason — to farm contribution to create a place for contestants to share their thoughts about the competition (cause I haven't found one yet). As for me, the problem set was nice, but there were some slight technical inaccuracies. But since I wasn't actually taking part in the contest, I could have missed a lot. If so, let me know in the comments.
By the way, I would also really like to know how was the competition held in your country.

P.S. If you are an EJOI 2021 medalist, than congrats, you probably did a great job already.So go on!!! See you on IOI 2022(hope it will be my first onsite IOI).

 
 
 
 
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13 months ago, # |
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LOL Oleh you have not participated in the live international Olympiad yet? LMAO xd

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    13 months ago, # ^ |
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    I have only participated in EJOI 2019 and InfoCup 2019 live :))

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      13 months ago, # ^ |
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      I have participated once live. And have two more years, like you.

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13 months ago, # |
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In Kazakhstan every contestant wrote ejoi in school and did stream in obs studio. Overall we got 4 bronze medals. I liked all problems. By the way will there be real medals or just грамоты and will there be upsolving somewhere?

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    13 months ago, # ^ |
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    The email we got from organaizers says: "The electronic certificates for participation as well as those for medals will be made available in mid-September". I guess this means there will be no physical medals.

    About upsolving..Well, I have no info either. The test cases are published on the official website by the way.

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    13 months ago, # ^ |
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    Hopefully, it will be uploaded on EOlymp. I will write here, when it will be ready.

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      13 months ago, # ^ |
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      Thanks

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      13 months ago, # ^ |
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      Wow, is EOlymp a well-known online judge in your country as well?

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        13 months ago, # ^ |
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        Sure, EOlymp is very popular in Azerbaijan. One of the EOlymp admins is the professor of the ADA University, famous coach in Ukraine Mykhailo Medvediev. He made EOlymp popular in our country. At the moment all students of ADA university have their assigments there, also schoolers prepare for their competitions on EOlymp.

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13 months ago, # |
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Thanks arsijo and oleh1421 for great translation and all organisation stuff they've done. I think that there could be more subtasks because blocks like 10/20/70 or 36/56/8 make you feel bad.

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    13 months ago, # ^ |
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    I'd like to express my disagreement. First, 36/56/8 is a great move (that I didn't expect from our organizers :) It wouldn't have been fair for a contestant that got so far to solve the first two subtasks to lose more than 15 points for not knowing SegTrees/BITs. But I think you were refering to the 56 and 70, weren't you?

    I believe that those problems were interesting, and it was worrh for them to gain this "international" attention (instead of them being published at some romanian TST), but, if you look at their solution, you really can't create any more subtasks :)). For example, first subtask in addk is a bruteforce solution with partial sums, while the second(and third) intends to ask you to make some more smarter sums. And kpart has O(N^3*MaxSum) for the first subtask, then O(N^2*MaxSum), then O(N*MaxSum (+N*N)), and it's really imposible to find something in between these margins. So, between not proposing the problem and proposing it (although kpart turned out to be a disaster*), proposing it would've been... better(?)

    *: In terms of how hard it was meant (I think) to be vs. what scores appeared in the contest

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      13 months ago, # ^ |
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      Yep, you definitely have a point + addk is a nice problem. But am I the only one who think that T*N*MaxSum is just to much for given constrains. At least it requires to much constant optimizations to get accepted. They could do something like this: add another subtask, that costs 60pts and put slightly lower constrains. And the last subtask for constant optimizations that costs 10pts.

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13 months ago, # |
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It was never mentioned where (and when) EJOI 2022 will take place, right?

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10 months ago, # |
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I was close to participating in it but sadly didn't make it in, tho I did try the problems and solved the first one (addk problem), what codeforces rating is that problem, and if so can I send my way of doing it to you so you can see if there can be made any optimizations?