Hello Codeforces!

We are excited to invite you to compete in CALICO Fall '25! The contest starts Sunday, November 9, 2025, at 4:00 p.m. PT and will be 3 hours long. Registrations are now open and will be until November 2nd, 2025, at 11:59 p.m. PT, so register here while you can! The contest will take place on our custom judge platform, and contestants can choose to compete either online or in-person at UC Berkeley!

In-Person Contest

The CALICO team is proud to announce the return of our in-person contest! Come compete LIVE at the UC Berkeley campus, learn from guest speakers, and meet the team behind CALICO! Use this link to register for the in-person competition, and keep in mind that you need to fill out BOTH the general registration form and the in-person registration form to come in person! As a reminder, the in-person event will take place on November 9th from 2-8 PM (PT). While the general registration form closes on November 2nd at 11:59 PM PT, the in-person registration form will close on October 26th at 11:59 PM PT to allow for in-person preparations.

About

The California Informatics Competition (CALICO) is a semiannual team programming contest organized by students at the University of California, Berkeley. We create original problems to encourage students to grow their problem-solving skills and learn algorithms in fun and exciting ways. Check out our website to learn more about the contest and join our discord server to get announcements, make teams, hang out, and more!

Contest Info

The contest will be 3 hours long and you can compete solo or in a team of up to 3. There will be around 8-12 problems spanning a wide range of difficulty for all skill levels. Some problems will have bonus test sets, where more efficient or advanced solutions can earn additional points. At least one of the problems will be interactive. Anyone can compete, but only pre-college teams will be eligible to win prizes. Editorials for some problems will also be available after the contest. More details will be released as the contest date approaches.

We’ve had a ton of fun creating these problems! We think there will be something interesting for everyone, regardless of whether you’re totally new or an experienced competitor.

Good luck with the contest!