Problem E appeared on Honk Kong online judge

Although the intended solution is O(n^2), the editorial provides a O(n) solution, as can be seen here: 2022 Mini Competition 3 Editorial

You can't have access to this site unless someone from your school paid the Hong Kong judge and registered you.

Problem H appeared ipsis litteris on a Japanese online judge

This one has already been discussed by the contest author: https://codeforces.me/blog/entry/142069.

Imagine if a Brazilian made the hardest problem equal to a problem only available on a Brazilian online judge (which is also Portuguese only) and problem E appeared on a Latin American training list. This would hugely favor Brazilians / latin Americans and be unfair to everyone else. Well, if you guys decide to make this contest rated, don't do different if the scenario I just described happens.