Australian Informatics Olympiad (AIO) Preparation

To prepare for the Australian Informatics Olympiad, get genuinely fluent in one allowed language and then practise reading problems and chasing subtasks — the three-hour, six-problem paper uses subtask scoring worth 100 points per problem, so partial solutions earn real marks and a points-first strategy beats trying to fully solve everything. The AIO is a programming competition for Years 7–12 that requires writing and submitting working code, judged automatically against test data.

What the AIO actually requires

The AIO is not a pen-and-paper logic test — it is a coding contest. You read a problem, design an algorithm, write a program, and submit it to an automatic judge that runs it against hidden test cases. Because each problem is split into subtasks (for example, a version with small inputs worth partial points, then larger inputs worth the rest), you do not need to fully solve a problem to score. The single most important strategic habit is to bank the easy subtasks across all six problems before grinding on a hard full solution.

The points-first strategy

Strong AIO performers rarely solve every problem perfectly. They read all six problems early, solve the easy first subtasks quickly — often a simple brute-force program is enough — and only then invest time in the harder subtasks where they have an idea. A beginner who confidently codes the first two problems and grabs early subtasks on the rest can score well. Chasing one perfect solution while ignoring free subtasks elsewhere is the classic mistake.

What to learn, in order

A practical training plan

1. Pick one language and get fast. Python 3 is friendly for beginners; C++ is faster for large inputs. Be able to read input and print output without thinking.
2. Train on ORAC. The Australian Maths Trust’s ORAC judge hosts past AIO problems with automatic marking — the best possible practice, with instant feedback.
3. Do past AIO papers under time. Simulate the three hours and practise the read-all-then-bank-subtasks routine.
4. Review every miss. When a subtask fails, find out whether it was the algorithm, an edge case, or a bug — debugging skill is half the contest.

Debugging: the half of the contest nobody trains

Most students spend their practice time learning algorithms and almost none learning to debug, yet a working program that scores beats an elegant idea that crashes. Under the AIO’s automatic judge, a single off-by-one error or an unhandled edge case can drop a whole subtask, so the ability to find and fix bugs quickly is worth as much as the ability to design the solution. Practise reading the constraints carefully (they tell you which subtasks a brute-force approach can reach), testing your program on the smallest and largest allowed inputs, and checking boundary cases such as zero, one, or maximum-sized data before submitting. A calm, systematic debugging routine — reproduce, isolate, fix, retest — turns near-misses into banked points and is one of the fastest ways to lift an AIO score without learning a single new algorithm.

How the AIO fits the bigger picture

The AIO is the entry exam to Australia’s informatics pathway, which leads through invitation-only contests toward the International Olympiad in Informatics. If you are still choosing between coding competitions, our AIO vs CAT comparison explains the difference between writing code and computational thinking, and the CAT preparation guide covers the no-code alternative. To understand how a strong AIO result leads onward, read our AIO qualification pathway guide. A free diagnostic can help confirm a student’s readiness for algorithmic work.

Format and dates last verified June 2026 against the Australian Informatics Olympiad and the Australian Maths Trust. Dates and rules change every year — always confirm with the AMT or your school before relying on a date.

Frequently asked questions