British Informatics Olympiad Preparation: BIO Round 1

Three questions, three hours, any language

The British Informatics Olympiad is the national computing competition for schools and colleges in Britain, founded in 1995. Round 1 is a three-hour paper with three questions, taken in school.

The detail that matters most for access: each question may be solved on any type of computer and in any language. A student who writes Python is as eligible as one who writes C++, which removes the single biggest barrier that stops students entering computing olympiads.

Questions are supplemented by written problems, so the paper tests reasoning as well as implementation.

Three questions is fewer than it sounds

An hour per question sounds generous until you see the structure. Each question comes in parts of rising difficulty, so a single question can occupy a capable student for the full hour and still have parts left.

That shapes the right strategy. A student should attempt the early parts of all three questions before committing to the hard parts of any one, because the early parts are where the reliable marks are and they are reachable with careful work rather than advanced algorithms.

Students who work through in order frequently never see question three, which is the commonest avoidable loss on the paper.

Multi-part questions are one question

BIO questions are built so that an early part usually establishes something a later part needs — a routine to write, a pattern to notice, a small case to generalise.

A student who treats the parts as three separate problems makes the last one considerably harder than intended. Reading the whole question before starting is a trained habit and it pays immediately.

What the paper actually rewards

Careful enumeration solves more BIO parts than students expect. Writing a correct brute-force solution quickly is often the right first move, and recognising when it suffices frees time for the parts that genuinely need more.

Simulation — modelling a described process exactly and running it forward — is a recurring BIO style where the difficulty is precision rather than cleverness.

Recursion and backtracking handle the combinatorial parts that appear in most papers, and dynamic programming appears in the later parts of harder questions.

The written problems ask for counts, explanations or proofs rather than programs, so counting carefully and arguing clearly are part of the paper rather than optional extras.

Who can enter

Students under 19 studying full-time at an establishment of Secondary or Further, but not Higher, Education in mainland Britain. Round 1 is genuinely open to Year 10 and 11 students, which corresponds to Class 9 and 10.

Students outside Britain cannot enter the official competition. The past papers remain excellent training for any computing olympiad, and we use them with students preparing for INOI and USACO for exactly that reason.

For schools: how Round 1 runs

Round 1 is sat in school, and the school chooses a date within the published window — for the most recent cycle, any date between early December and late January.

That flexibility makes it unusually easy to administer: a school can fit the paper around its own timetable rather than clearing a fixed national date. The supervising teacher does not need to be a programmer.

Registration arrangements and the current window are published each year at olympiad.org.uk, so confirm them before planning a cohort.

Where it leads

Strong Round 1 performers are invited to the final round, from which the UK team for the International Olympiad in Informatics is selected.

For students not on the British route, BIO sits naturally alongside the Canadian Computing Competition and the Australian Informatics Olympiad, both of which are open to international schools and test overlapping skills in different formats.

How the classes run

Live online group classes, maximum eight students. Students write and submit working code during the session rather than discussing approaches in the abstract, because the paper requires a program that runs.

Past Round 1 papers are worked under full three-hour conditions in the closing weeks, reviewed for time allocation across the three questions as much as for correctness.