🥈 Coding and computer science
Informatics Olympiad: competitive programming for school students
The Indian informatics olympiad programme tests problem solving with algorithms. It suits students who enjoy puzzles and have a little programming experience.
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At a glance
Indian Informatics Olympiad (ZCO, INOI and beyond)
Syllabi, patterns and dates change. Check the official source below for the current notice.
Organiser
The Indian Association for Research in Computing Science (IARCS) runs the programme. Check the official site.
Stages
Rounds such as ZCO and INOI feed a training and selection route. Rules and dates change.
Languages
C++ is the most common in competitions, and Python and Java are also used. Check the rules.
Who it suits
Students who like problem solving and are comfortable with a programming language.
What it covers
Topics and skills
Basic algorithms
Loops, arrays, sorting and searching.
Number tricks
Prime numbers, GCD and modular arithmetic.
Data structures
Stacks, queues and later trees and graphs.
Greedy and dynamic programming
Core techniques, learned gradually.
Complexity
Estimating whether a solution is fast enough.
What earns marks
- Correct and efficient solutions
- Careful handling of edge cases
- Practice with many problems
Common mistakes
- Learning too many topics shallowly
- Not testing edge cases
- Copying solutions
- Ignoring time limits
A plan
How to prepare, in four phases
- 01Phase 1: One language well
Pick C++ or Python and be fluent.
- 02Phase 2: Core algorithms
Sorting, searching, simple number theory.
- 03Phase 3: Practice problems
Solve past olympiad and online-judge problems.
- 04Phase 4: Contests
Join practice contests and review solutions.
Free practice
Practise here, no sign-up
Prime number checker
Check whether a number is prime, see its prime factorisation, all its factors, the nearest primes, or list every prime up to 100,000.
Use the tool →LCM & HCF calculator
Find the lowest common multiple and highest common factor (GCD) of up to eight numbers, with a prime factor table that shows why.
Use the tool →Games and practice
Also useful
Official source: IARCS: Indian Computing Olympiad. Check it for the current syllabus, pattern and dates. We do not promise marks, ranks or selection.
Read
Guides
Live online course
Informatics Olympiad preparation (India): 48 live classes
16 weeks, 3 a week, from ₹483 a class in India (small group). See the week-by-week plan, the price for your country and how the demo class works.
FAQ
Informatics Olympiad: questions people ask
Which language should I use?
C++ is the most popular for contests. Python is easier to start with and allowed in many rounds. Check the rules.
Do I need advanced maths?
Some number theory and logic help, and school maths is a good base.
Is it only for toppers?
No. Anyone who enjoys problem solving can start.
Can you help?
Yes. Share your syllabus and level and a teacher from our network is matched to you before anything is booked.
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Share the exam, class, date and what feels hard. We suggest a starting point and confirm the format before anything is booked.
- Tell us the learner’s age or grade and goals
- We’ll suggest a suitable class or learning path
- We’ll confirm format, timing and fees with a parent or guardian
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