Previous Contests: 2023-2024 Season

2024 US Open Contest Results.

2024 February Contest Results.

2024 January Contest Results.

2023 December Contest Results.

Previous Contests: 2022-2023 Season

2023 US Open Contest Results.

2023 February Contest Results.

2023 January Contest Results.

2022 December Contest Results.

Previous Contests: 2021-2022 Season

2022 US Open Contest Results.

2022 February Contest Results.

2022 January Contest Results.

2021 December Contest Results.

Previous Contests: 2020-2021 Season

2021 US Open Contest Results.

2021 February Contest Results.

2021 January Contest Results.

2020 December Contest Results.

Previous Contests: 2019-2020 Season

2020 US Open Contest Results.

2020 February Contest Results.

2020 January Contest Results.

2019 December Contest Results.

Previous Contests: 2018-2019 Season

2019 US Open Contest Results.

2019 February Contest Results.

2019 January Contest Results.

2018 December Contest Results.

Previous Contests: 2017-2018 Season

2018 US Open Contest Results.

2018 February Contest Results.

2018 January Contest Results.

2017 December Contest Results.

Previous Contests: 2016-2017 Season

2017 US Open Contest Results.

Third Contest (February 2017) Results.

Second Contest (January 2017) Results.

First Contest (December 2016) Results.

Previous Contests: 2015-2016 Season

2016 US Open Contest Results.

Third Contest (February 2016) Results.

Second Contest (January 2016) Results.

First Contest (December 2015) Results.

Previous Contests: 2014-2015 Season

2015 US Open Contest Results.

Third Contest (February 2015) Results.

Second Contest (January 2015) Results.

First Contest (December 2014) Results.

Previous Contests: 2013-2014 Season

2014 US Open Contest Results.

2014 March Contest Results.

2014 February Contest Results.

2014 January Contest Results.

2013 December Contest Results.

2013 November Contest Results.

Previous Contests: 2012-2013 Season

2013 US Open Contest Results.

2013 March Contest Results.

2013 February Contest Results.

2013 January Contest Results.

2012 December Contest Results.

2012 November Contest Results.

Previous Contests: 2011-2012 Season

2012 US Open Contest Results.

2012 March Contest Results.

2012 February Contest Results.

2012 January Contest Results.

2011 December Contest Results.

2011 November Contest Results.

On-Line Contests

The USACO holds periodic web-based contests during the academic year, and in the late Spring conducts the US Open, our "national championship" exam. Contests generally run for three to five continuous hours in length, although for maximum flexibility, you are free to schedule this block of time anywhere within a Friday-to-Monday contest weekend --- your timer starts when you log into the contest and download the problems. Contest tasks are presented on the web, and you submit your final solutions through a simple web interface. Participation is free and open to all.

Contests are offered in four divisions:

  • Bronze, for students who have recently learned to program, but who have no training in algorithms beyond basic concepts like sorting and binary search.
  • Silver, for students who are beginning to learn fundamental problem-solving techniques (e.g., recursive search, greedy algorithms) and fundamental data structures.
  • Gold, where students encounter more standard algorithms of a more complex nature (e.g., shortest paths, dynamic programming) and more advanced data structures.
  • Platinum, for advanced students who are well grounded in algorithmic problem-solving techniques, who wish to challenge themselves with sophisticated and more open-ended problems.

All participants start in the bronze division, and those who score particularly well in a contest will be promoted to the next division. Contestants scoring particularly highly will be automatically promoted to the next division while a contest is running; others will need to wait until results are announced at the end of the contest to see if they meet the (contest-dependent) cutoff for promotion.

Detailed technical specifications and rules for our contests are available here.

The Road to the IOI Team

Based on the results of the web-based contests throughout the year (with particular emphasis on the US Open), as well as performance in the on-line training pages, approximately 16..24 students are invited to a rigorous academic training camp in the early summer, hosted at Clemson University. At camp, half a dozen more contests in addition to a full schedule of computing-related and extracurricular activities fill out the week of activities. At the end of camp, the top 4 students are selected by the USACO staff to represent the USA at the International Olympiad in Informatics (IOI). The IOI is held each summer by a different host country --- for example, Australia (2013), Taiwan (2014), and Kazakhstan (2015). The USACO occasionally also participates in regional contests, such as the Central European Olympiad in Informatics (CEOI).

To be eligible for selection as a USACO finalist and ultimately as an IOI team member, you must be enrolled in a high school (or junior high/middle school) for at least one semester in the school year before the IOI. You can concurrently take courses at other institutions, including colleges and universities. You must either be a US citizen or a resident of the USA during the first half of the school year. IOI team members from countries other than the USA are not eligible to be USACO finalists (and this includes students who have made commitments to other countries that could conceivably result in their being selected for an IOI team prior to USACO camp).

To be selected as a finalist, you must excel in your participation in USACO web-based contests through the year. The coaches may drop one contest when averaging scores and determining trends, but a student who misses several contests is less likely to be chosen. Students in their senior year, and finalists from previous years generally face a much stricter set of criteria for selection than younger students.

Expenses for the USACO training camp are paid by the USACO, although participants are asked to fund their own transportation to the camp if possible. For the IOI, all expenses, including transportation, are paid by USACO.

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2023-2024 Schedule

Dec 15-18: First Contest
Jan 26-29: Second Contest
Feb 16-19: Third Contest
Mar 15-18: US Open
For each contest, USA students
wishing to receive a certified
score in the platinum contest
must start Saturday at
12:00 ET, when platinum problems
will be first released
(see contest details for
more detailed instructions)

May 23-June 1: Training Camp
Jul 21-27: EGOI (The Netherlands)
Sep 1-8: IOI (Egypt)