For the ninth time, the Italian national contest (valid for the selection of the Italian IOI team) will be mirrored into an online contest. The contest is primarily intended for high school contestants, but everyone is welcome to participate! There are both easy subtasks (div2A) and very hard ones (div1D+), so it can be enjoyable both for newcomers and for very high rated contestants.

This year, there will be three online contests in total, held in the following order:

1. a mirror of the practice contest (featuring original problems);
2. an official (rated) Codeforces round based on the main contest;
3. a mirror of the main contest.

Official Codeforces round

The format of the Codeforces round (2.) will be the usual Codeforces format, so you don't need any extra steps to register / participate. Another blog will be published a few days before the round.

Other rounds

About the other rounds (1. and 3.):

1. The problem statements will be available in both English and Italian.
2. Tasks will be IOI-like (with graders and subtasks) and you will have 5 hours to solve them.
3. The only language allowed is C++.
4. The time window for the practice contest (featuring original problems) will start on 2024 September 13th, 22:01 UTC and will end on 2024 September 25th, 21:59 UTC.
5. Then, a rated Codeforces round based on the main contest will be held on September 27th (time to be decided).
6. The time window for the main contest will start after the official Codeforces round, i.e., on September 27th (time to be decided).

The contests' timing will be USACO-like: you can decide when to start your 5-hours time window (after the login), but the contest will end at the given time regardless of your time window.

If you want to participate, you must:

1. Visit the contest website: practice contest, main contest.
2. Click the link "register", fill out the form and then click on the register button and then "back to login"
3. You can now log in with the same username and password you used to sign up
4. If the login is successful you will be ready to participate, just wait for the contest to start! (And maybe save the page in your bookmarks, so that you can quickly get back to it when the contest begins)
5. When the contest starts, you will see a red button. Click it when you want to start your 5 hour time window!
6. Good luck and have fun!

Ranking: The ranking of the online contest will be available at https://mirror.oii.olinfo.it/ranking when the contest starts.

Upsolving: After the end of the contest, tasks will be uploaded in the Italian training website https://training.olinfo.it (localised also in English), section "task & quiz archive", where they will be available for online evaluation (after registering to the website).