Overview
The USA Computing Olympiad (USACO) runs online programming contests for pre-college students and is the route to the United States team for the International Olympiad in Informatics (IOI). Anyone can take part in the online contests.
Who can take it
The USACO states that all are welcome in its online contests. Only pre-college students from the USA qualify for the training camp and team selection.
Levels or stages
Divisions
Contestants start in Bronze and move up through Silver and Gold to Platinum. A perfect score during a contest promotes a contestant immediately. Other contestants are promoted after the contest if they reach the promotion threshold. Promotions have traditionally been permanent, even across seasons.
Exam pattern
| Item | Detail |
|---|---|
| Length | Typically four to five contiguous hours, started when the contestant chooses within the contest window |
| Problems | Three to four algorithmic problems |
| Languages | C, C++, Java or Python |
| Judging | Each solution is run on hidden test cases with feedback on each |
Marking and results
Points depend on how many test cases a program solves within the time limit. The usual limit is about 2 seconds for C and C++ and 4 seconds for Java and Python. The USACO notes that C++ is the only language supported at the IOI, so it is emphasised at higher levels.
Fees
The USACO states there is never a fee for participation.
How to apply
Create an account on the USACO site and join any open contest during its window. The site lists the contest schedule.
After the exam
Strong pre-college United States students can be invited to the training camp and considered for the IOI team.
Preparation tips
Practise past problems at your current division on the USACO site.
Learn standard algorithms and data structures, and practise in C++ if you aim for the IOI.
Is USACO only for students in the United States?
The online contests are open to all. Only pre-college USA students qualify for the camp and team selection.