Hello Codeforces,
Yesterday marked the end of the Turkish TST. While the official results haven't been announced yet, I believe I've qualified for the national team.
Over the years, I've solved thousands of problems across various platforms. However, I’m aware that unlike many other Olympiads in Informatics, the IOI includes heuristic, output-only, and many interactive problems. I’ve also heard that since 2016, the IOI has shifted from being primarily algorithm/technique-heavy to featuring more ad-hoc and logic-based problems. As someone still relatively inexperienced with actual IOI tasks, I can neither confirm nor deny these claims.
Right now, I’m trying to figure out the best way to make use of the few months ahead. I’d truly appreciate any recommendations on high-quality IOI preparation resources. My goal is for this blog to serve as a cornerstone for IOI preparation—a place that brings together everything related to the IOI, and the IOI only.
Thank you for your interest!
i support you whitebird GL
Thank you so much <3
Good luck for ioi orz
Congratulations!
In general, in IOI, strategy matters a lot more than on CodeForces. You should do a lot of IOI-style virtual contests to get used to it and find a strategy that works the best for you. Upsolving is also important — try to upsolve all the problems relevant for your desired medal, so for example, if you're aiming for silver, you should upsolve all the problems with 50+ solves. When upsolving, try to solve as many subtasks as you can on your own (it is important to be able to solve and implement subtasks fast so that you don't miss any obvious points) and then read the editorial and try to code the rest. You can use oi-checklist to track your progress. This is how I trained for IOI.
As you've mentioned, modern IOI problems are a bit different than the old ones. I'd say IOI problems from 2015+ are the most relevant ones to train on. After you solve most of them, you can move on to other olympiads, and the older editions of IOI. JOI problems are also great to train on, but I wouldn't recommend starting with them, as they are quite hard, which could be demotivating.
You can find past IOI tasks in oj.uz and Eolymp Basecamp (where you can also virtually participate).
Thanks :)
Thank you so much for the advice. It's great to hear these from a gold medalist and EGOI winner! orz
I AM SO EXCITED
I will watch your score through all 5 hours sorry :(
Thank you so much! PieArmy will win IOI '26 '27 and '28 for sure. So strong... I am very lucky to have you as a teammate at BOI 2025!