Hi all, I found questions for the Russian, South Korean, and Polish olympiads here:
https://www.acmicpc.net/category/500
https://www.acmicpc.net/category/55
https://szkopul.edu.pl/p/default/problemset_eng/oi
For Russia, what's the precise difference between ROI, the Russia High School Programming Contest, the Russia Team High School Programming Contest, the Russian Olympiad for Schoolchildren in Informatics, and the Russian Olympiad in Informatics Regional?
For South Korea, what's the precise difference between the KOI 1st competition, 2nd competition, and city/province finals?
For Poland, what's the precise difference between the 1st, 2nd, and 3rd rounds?
Thanks!
I'm only informing you about KOI.
KOI previously divided competitions into regional preliminaries, regional competitions, and national competitions. Currently, it is divided into the first competition and the second competition nationwide, regardless of region. The first competition has the characteristics of a preliminary competition, and the second competition has the characteristics of a final competition because the first competition must have more than a bronze medal in the first competition to advance to the second competition.
The point here is that unlike other countries' informatics Olympiads, South Korea runs the national team selection test and domestic competitions independently. Therefore, if you want to check Korea's national team selection test, you should check the problem through the KTSC(Korean Team Selection Contest) source, not the KOI source.
The KTSC problems can be found at https://boj.kr/ktsc.
I can tell you about the Polish Olympiad. 1st round is an online round. Approximately 400 of the top students from the first stage advance to 2nd round, which is held at different places around the country (usually some universities). Around 100 students advance to the final stage of the Olympiad (3rd round), which is held at the University of Warsaw. The tasks become more difficult with each round.
The last sentence isn't that true. An important thing you didn't mention is that 1st round (online) lasts for more than a month, this gives a lot of space for some difficult problems or problems with hard implementation or whatever is not suitable for onsite 5h rounds. So a lot of problems from 1st round are harder than problems from 2nd and 3rd.
For Russia, isn't it obvious from it's names..?
I'll say this about the Russian Olympiads. "ROI" and "Russian Olympiad in Informatics Regional" are in fact the same Olympiad, but "ROI" is the final of the Olympiad, and "Russian Olympiad in Informatics Regional" is the selection for this final. Of course, in this selection the tasks are much easier.
"Russian Olympiad for Schoolchildren in Informatics" is MSTISLAV KELDYSH olimpiad(here i can be wrong). It's 5-8 grade.
The "the Russia High School Programming Contest" and "the Russia Team High School Programming Contest" are just other Olympiads, different from the first three. They also contain interesting and challenging tasks.