erray's blog

Olympiad Training
By erray, 3 years ago, In English

Hi everyone,

Our team selection test will be in a month probably and I'm bad at olympiad style competitive programming, I mean I'm bad at Codeforces style but olympiad style is the next level, I have no training and solved hardly any olympiad problems, according to my friends and blogs I have seen, problem styles can be very different, I looked up for the blogs like this and either they were old, or they had no information, so which problems should I solve, from which olympiads and assuming I get selected, how should I train for IOI ?

(Also please don't cyberbully me, I know my English is trash.)

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3 years ago, # |
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i don't want to cyberbully you but this is so cyan

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    3 years ago, # ^ |
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    This is a bit heartbreaking and completely accurate.

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3 years ago, # |
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Problem Sources:

JOI — Japanese Olympiad in Informatics

POI — Polish Olympiad in Informatics

USACO — United States of America's Computing Olympiad

BOI — Baltic Olympiad in Informatics

APIO — Asian Pacific Olympiad in Informatics

CEOI — Central Europe Olympiad in Informatics

Note that APIO problems may sometimes contain out-of-IOI-syllabus topics but are still of good quality.

And please, do yourself a favor and use https://codeforces.com/blog/entry/62898#comment-468763 !

I will finish with a self note. From my experience (but I assume more experienced users will comment soon), quality OI problems require the competitor to make observations which are key to solving the problem — some invariants, parity arguments, a lower / upper bound on some important measure, greedy claims etc, and the ability to these observations comes with practice, which is the fun part :)

Also, a big difference between codeforces and IOI — subtasks. In a bunch of cases, the difference between medal X and medal X-1 is whether or not you solved some subtask, subtasks are important! Sometimes, a subtask is added on purpose to direct the competitor to some part of a solution which is worth more points, for example uncovering an important case or providing a different way to think about the problem. Even if you only intend to solve the full problem straight, please read the subtasks before you begin solving!

Good luck :D

lior5654

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