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!

As the question title suggests, what specific past problems do the problems of the recent Educational Codeforces Round 147 remind you of?

I think this is of interest especially to newer contestants looking for extra practice, also maybe others as well.

Here are the problems for Educational Codeforces Round 147: https://codeforces.me/contest/1821

And here's the editorial: https://codeforces.me/blog/entry/115296