Our mail server, which manages, is experiencing difficulties and is temporarily unable to send emails (but can still receive emails); for the time being, official emails will be sent from
arohan19 (at) berkeley (dot) edu


The CALICO Informatics Competition is a high-school programming competition hosted by students at UC Berkeley. We create contest problems to promote the understanding of useful algorithms and encourage students to grow their problem-solving skills! To see some past problems, check out our Problem Bank.

What Do We Do?


Our biannual programming competition is for students up to 12th grade. These contests are run during the fall and spring season, and consist of a large number of problems meant to be solved by teams. Come prepared to bring your best, and we will take care of the rest!


Our CALSUCO summer contests are open to participants of all ages! Compete as an individual; these contests consist of multiple online, bite-sized rounds run during the summer months. Keep your skills fresh with these lower-stakes, casual contests!

Editor's Choice

These problems almost made the cut for our competitions--so close! These contests are released on our problem bank before CALICO competitions; no registration necessary! Same format, same rules--feel free to use these as practice material, tryouts for teams, or to test your computer setup!

Congratulations to our winning teams
of CALICO Fall '23!

Red and Black Blocks of Crayons 99 points
Agastya Goel | Rohin Garg | Austin Geng
👻 Boo Tao will getcha 99 points
Bing-Dong Liu | Brian Xue | Thomas Liu
cout<<ans; fuwwies :3 8d from BracketCS / CerealCodes 95 points
Alex Liang | Eric Hsu | Daniel Kim
sudo 87 points
fextivity | hollwo_pelw | khuepr123
Modern Prometheus 87 points
JellyFishy | MetalPower | aufannn

...and congratulations to our top college teams!

M(IT)^2 - MIT Informatics Tournament from M(IT)^2 100 points
Peter Zhou | Sam Zhang | Jason Gonzalez
Trie Struct from Jollybee 87 points
Zanite | naga-unyu | Vector


11/18 The CALICO Fall '23 has officially concluded! Thank you for participating in this year's competition.

CALICO Spring '24 Online

Date Time (PT) Event
2/6/2024 12:00AM Registrations Open!
4/24/2024 11:59PM Registrations Close
4/25/2024 6:30PM CALICO Training Workshop

Hosted by Thomas Liu with X-Camp

USACO Finalist, 2nd Place CALICO Fall '23

4/26/2024 7:30PM CALICO Training Workshop Ends
4/27/2024 2:30PM Guest Speaker Event

Hosted by Professor Yokota of UC Berkeley

4/27/2024 4:00PM Contest Begins!
7:00PM Contest Ends
7:30PM X-Camp Guest Speaker Event

Topic TBA

10:00PM Winners Announced!

Want to be the first to know when registrations open? Sign up for our email list to get updates sent right to your inbox!


CALICO is open to everyone! However, only teams of pre-college students are eligible to win prizes.

We define "pre-college student" as anyone who has not entered college/university.

Once you've registered, you can expect an email from us after the registration deadline about how to access the contest site. For more information on this, see "Contest Autograder Logistics" under our Contest Guide.

In the meantime, check out our "Preparing for the Contest" checklist, also found on our Contest Guide!

If you know how to work with conditions, loops, strings, and integers, you can start solving problems! At a higher level, our problems give students a preview into concepts taught at various classes within Berkeley's CS department. Regardless of whether you're just starting out or a seasoned programmer, there will be something for you!

All you need is a computer running an approved programming language, a text editor to work with, and a stable internet connection! For a list of approved programming languages, see "Approved Languages" under our Contest Guide.

A maximum of 3 people are allowed to be on a team for CALICO. You're free to have smaller teams, but it's more fun with friends!

Yes! We will be holding an in person contest this Spring, at the same time as the regular online contest. It will be held on the University of Calfornia Berkeley. Keep an eye out for more information!

The following prizes will be awarded to the winning teams (1 per team):

  • 1st Place: $200 Amazon Gift Card + $200 X-Camp Discount Code
  • 2nd Place: $100 Amazon Gift Card + $150 X-Camp Discount Code
  • 3rd Place: $50 Amazon Gift Card + $100 X-Camp Discount Code
  • 4th & 5th Place: $25 Amazon Gift Card

All X-Camp discount codes are per student on the winning team!

All other students will additionally receive X-Camp discount codes!!

We will also be raffling off the following prizes to individual contestants:

  • 5x $200 X-Camp New Student Tuition Certificates
  • 2x 1 Month Discord Nitro Subscription
  • 6x $10 Gift Card (Amazon, Steam, Apple/Google Play, League of Legends)
  • 1x CALICO Sandal (Left)*
  • 1x CALICO Sandal (Right)*
  • 1x Brick*

More information on how the raffle will be run and how you can participate can be found under "Raffle Logistics" on our Contest Guide!

All prizes will be distributed to the winning teams following the contest.

*Available for shipping to US only

Check out our Contest Guide to learn about the rules, the structure of the contest, and other technical details!

Invite your friends and fellow programmers to join CALICO! During registration, there will be a special section on the form for them to add the email of the person who referred them. Then, simply collect your reward after the contest!

Sticker Reward*: If you refer at least two people, you'll receive an exclusive CALICO sticker!

Grand Prize*: The participant with the most referrals will win an awesome limited edition signed CALICO T-shirt!

Note that there are a couple restrictions on what counts as a valid referral. Make sure your referrals don't go in vain by checking out the full list of rules and restrictions under "Referral Program" on our Contest Guide!

*Available for shipping to US/Canada only

We've condensed most of the crucial information in this one-page cheat sheet!

If you have a question, don't hesitate to email us at! Feel free to also reach out to us on Discord.

Join Our Email List!

Stay in the loop for CALICO announcements by signing up for email notifications! Our email list will only notify you when contest registrations open, along with other important updates.

Visit Our Problem Bank!

Past contest problems, along with their full test cases and solutions, can be accessed here! We highly encourage you take a look. Practice problems will also be published here occasionally, so check back here every once in a while!


Thank you to these organizations for making our events possible! Interested in supporting CALICO? Shoot us an email at!

Community Partners

Check out some of our peer organizations!