Art of Problem Solving (AoPS)
AoPS hosts one of the largest online communities for competition math, with:
- A comprehensive archive of past contest problems
- A free practice tool
- A full curriculum of textbooks and online courses.
What's Available
Forum & Problem Archive
The AoPS forum contains discussions and solutions for almost every major competition. If you want to find the official problems and community solutions for any contest, the AoPS forum is the first place to look.
Alcumus
A free adaptive practice tool that feeds you problems based on your performance. Alcumus is one of the most efficient ways to build problem-solving fluency without needing to manually hunt for problems.
AoPS Wiki
A community-maintained wiki covering olympiad topics, theorems, and techniques. Useful for quickly looking up a specific theorem and seeing worked examples.
Books
The AoPS textbook series (Introduction to Algebra, Introduction to Number Theory, etc.) are widely considered the standard curriculum for olympiad preparation.
Tips for Using AoPS
- Search the forum by contest name and year to find past papers with full solution discussions.
- On Alcumus, don't skip problems — working through ones you get wrong is where most of the learning happens.
- Read other people's solutions even when you solved the problem yourself. There is almost always a cleaner approach.