libobil's blog

Preparing for IOI
By libobil, history, 12 months ago, In English

Hi guys! I'm wondering about what is the best way to prepare myself for IOI. I've been to IOI, but I seek better results. For my preparation, I'm solving tasks in oichecklist, currently USACO and JOI Spring Camp 2018-2023. Do you have any suggestions of what other tasks I could focus on solving? Thanks beforehand.

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12 months ago, # |
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Why is this getting downvoted?

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12 months ago, # |
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A gm asking for an advice, seems like it's going to be an interesting blog to follow :)

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12 months ago, # |
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Actually, taking in consideration last year(2023)'s problems and their authors, solving JOI SC and OC seems like a good strategy =)

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    12 months ago, # ^ |
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    (grats for GM one more time btw!)

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    12 months ago, # ^ |
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    What is OC ?

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      12 months ago, # ^ |
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      likely to be the Open Cup.

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      12 months ago, # ^ |
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      JOI Open Contest. It's similar to JOISC, but it's a one-day contest with 3 tasks and 5 hours. Also, unlike JOISC, which only has Japanese slides as editorials, (recent) JOIOC editorials are available in English.

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12 months ago, # |
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What basically always worked for me is lots of simulations of old olympiads (mostly stuff from OI checkilist, foucs on JOISC, IZHO, APIO, USACO) and also doing atcoder problems.

Although atcoder problems are much more math heavy, I do find them better OI preparation than codeforces problems (or at least old codeforces problems). Good luck at IOI!

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    12 months ago, # ^ |
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    Well, I've been doing many virtual competitions (mostly IOI and IZHO), and the majority of them were successful, but it's a lot easier than the competitions themselves. The differences between them are too many to fit in one sentence (the feeling of being at the competition, the different sleep schedule, etc.), so for me doing VCs isn't enough. If you know of any way to train strategy, please, do tell!

    As for atcoder, I never really gave it a chance, could give it a try. Thank you!

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      12 months ago, # ^ |
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      Ah well there isn't much you can do about that honestly. You'll never be able to perform at competitions as well as you do in vcs, but the following is still true: the better you do at vcs the better you'll do at the competition.

      One thing which might help is getting a practice buddy, who you'll do vcs with and talk about the problems :)

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        12 months ago, # ^ |
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        Yeah, It would help. I need to get the other Bulgarian competitors to practice with me, so we can suffer together :D

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      12 months ago, # ^ |
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      So you are talking about stress during Olympiad. Honestly, the best thing is to participate in as many contests (not virtual contests) as possible. You will naturally get used to stress. You could do other activities to build up your spiritual strength, but I can't come up with any out of the top of my dome.

      I remember reading a blog about running marathons and building said mental strength. You may give it a try.

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12 months ago, # |
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Considering you are an grandmaster i have to assume you are shooting for gold.

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    12 months ago, # ^ |
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    Well, at least silver, because at IOI 2023 I scored 91st place. A gold would be nice though :D

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      12 months ago, # ^ |
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      Well good luck with that , im currently practicing to get to IOI

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12 months ago, # |
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cses.fi problems and full OI simulations can always help. Try putting emphasis on your weaker subjects while practicing. Good luck!

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    12 months ago, # ^ |
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    I will try the tasks in cses.fi. As one of my weaker subjects are interactive tasks, I currently think of solving the ones in the problem set in a row :)

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12 months ago, # |
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For gold, you need to be comfortable fully solving 3-4 tasks on any topic.

Read the syllabus and spend a few days on each topic you think you are weak.

I believe that training with whatever is the most fun is the way to go since you automatically settle with challenging problems.

JOI problems are of good quality and challenging. APIO problems are too technical, but that makes for good practice. USACO problems are usually pretty good. More recent BOI and CEOI problems are good as well :p You can also try some ICPC problems from the finals or regionals, but they are not so fun and more technical. OpenCup problems are usually high quality but can be a bit technical. https://oj.uz/problems/source

Also don't forget to train both solving and coding since time spent not coding is time spent thinking.

Why ctrl+enter doesn't work

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    12 months ago, # ^ |
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    I agree, still, USACO, APIO and JOI have the best problems out there (excluding IOI). I've never actually solved ICPC seriously, could give it a try, thank you :)

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12 months ago, # |
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I don't know if I am qualified to answer this, as I got silver in IOI 2022 without getting a single AC... lol

After getting selected to the national team, I used to do a bunch of old BOI and CEOI problems to practice. Before that, I did several of the easier JOISC problems from every year (based on the solves count in oichecklist). If you're looking to train ad-hoc skills, newer BOI or CEOI problems are good (I swear, I don't understand how they manage to come up with such... interesting... communication problems!)

As for virtual IOI-style contests, I would say it depends on how much you are willing to play on the 'strategy' side aside from the actual 'problem-solving' side. Back then I thought that I wouldn't be able to get AC on any tasks, so I often practiced my strategy of getting as many subtasks as possible using the virtuals. I used several newer IZhO contests for this. If you're aiming for gold, though, I don't think this would be very applicable.

Lastly, I find it useful to write down a reflection of what happened during the virtual contests you do, or even after solving a problem. I like to focus more on the takeaways I learned rather than writing an editorial/writeup of the solutions. I guess it helped make the things I need to improve on stick to my brain.

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    12 months ago, # ^ |
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    Well, I think we all aim for gold, but as I have two attempts left, I first need to get to the national team, then think of the medal I would get. Still, IOI preparation should be an all-year activity. I don't have a specific goal for me, such a goal should be set when you are at your all-time high. And yet, I still have work do to to reach this all-time high :)

    Don't think whether you're qualified to answer, I've written this blog so we could share some tips with each other, as I don't think there's a person, who knows the set of all useful things to do for your improvement.

    Well, as the most solved task in IOI 2022 has 51 full solutions, and in IOI 2023 the most solved task has 28 full solutions, it seems in the upcoming IOIs that getting AC won't be in the requirements for getting a silver medal.

    I will try writing down what happened during my VCs. I do some kind of self-reflection of the competition, but writing it down could help.

    Thank you :)

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12 months ago, # |
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Skill issue. Get good :)

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    12 months ago, # ^ |
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    Момчета, защо не решавате задачки

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12 months ago, # |
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just get better

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11 months ago, # |
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Bro just won IZHO, the preparation seems to be nice.

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