Updating from time to time to reach more guys..
Since 2019 and I receive very positive feedback about the quality of my problem selections in my international supervision. I intended to make my problem lists public one day to help trainees to train in a more efficient and effective way.
This program started in 2016 and has been changed and improved a lot based on the received feedback from my trainees. I ended up with 2 big lists of problems: one for guys training toward IOI and another for ICPC/OnlineContest styles. Specifically 4 critical features:
Problem difficulty level [1-10] per problem is a manual weighted average of the assigned levels from my trainees’ sheets. A common complaint about 'online tools/ways for ranking problems by difficulty' is that they are not accurate. The issue is more severe for OI problems.
Problem importance level: ~ 5 levels (important, very interesting, interesting, good, normal/boring/repeated). Trainees solve a lot of problems that many of them are repeated or boring ideas. To maximize the training outcomes, one should train on unique/interesting ideas much more. Something that most of us can’t figure out easily.
Editorials. Many interesting problems may not have editorials (or have hard to understand editorials). I used to ask trainees to write some summary of how they solved a problem. Circulating these editorials between my trainees made it easy for them to get problems solved.
Submissions info: In Trainees Submissions page, ~25k submissions of my trainees. Per problem info (status, submissions count, times for reading/thinking/coding/debugging, category, subjective level, and a comment. You may use it to know some details about how others performed with the solved problem.