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7 Tips to Win the International Olympiad in Informatics (IOI)

For all young programmers and problem solvers, the International Olympiad in Informatics (IOI) is the perfect competition to showcase your skills. Featuring some of the world’s most difficult algorithmic challenges and programming tasks for students, the International Olympiad in Informatics is an internationally-recognized, highly prestigious computer science and informatics competition for high school students to compete in, solving complex problems, demonstrating abilities in logical and mathematical reasoning, quick-thinking, creativity, and computer science.

What is the International Olympiad in Informatics (IOI)?

The International Olympiad in Informatics (IOI) is an annual programming competition for talented high school students around the world. The IOI has challenged young programmers to solve complex computer problems that would push the limits of most industry professionals in their ability to solve complex mathematical and algorithmic problems, and one’s logical thinking and coding ability.

The IOI was founded in Bulgaria in 1989 with the vision of cultivating passion and excellence for computer science in the next generation and providing a global stage for them to showcase their talents. Over the last 30 years, the IOI has grown, with students from 90+ countries participating, and establishing itself as one of the most prestigious programming competitions in the entire world.

Competing in the IOI is already a difficult feat and requires a wide range of technical and soft skills. Students have to creatively solve difficult tasks within a limited time utilizing their deep understanding of algorithms and mathematics that underlie each problem. Olympiad contestants represent the best in their countries after qualifying in their national Olympiad, and around the world, with participants becoming future leaders in innovation in computer science. The IOI has and will continue to serve as a center for excellence and prestige, with millions of aspiring computer science students looking to it as a goal to reach and with companies, colleges, and alumni looking to it as the next generation of innovators in tech.

Is the International Olympiad in Informatics (IOI) Prestigious?

IOI is undoubtedly a prestigious competition, being one of the oldest and most respected programming contests in the entire world. It is the second largest international Olympiad, behind Mathematics, and hosts some of the most talented high school programmers and computer scientists in the entire world. Even qualifying for the IOI means that you are amongst the top 5 high school programmers in your entire country, and performing well internationally showcases your excellent problem-solving abilities, computational thinking skills, and the potential to become a leader in the tech field. IOI alumni have gone on to attend the most prestigious universities in their own countries and throughout the entire world, found major tech companies, become world-renowned professors in computer science and mathematics, and more.

Who is Eligible to Participate?

The International Olympiad in Informatics is a relatively open competition, where any high school students under the age of 20 can participate. Each participating country selects a team of up to 4 students to represent them at the IOI, with a selection process that usually involves a national Olympiad, such as the British Informatics Olympiad in the UK or United States of America Computing Olympiad in the United States, which Lumiere also has an article on. The selection process within each country varies but usually involves a series of qualification contests, followed by a national competition, and concluding with training camps for the top 4 students.

Timeline and Structure of International Olympiad in Informatics (IOI)

The International Olympiad in Informatics begins with every country running their national circuit to find their national team. The top-performing teams and individuals from these national competitions then advance to the IOI, which is held annually in a different host country. The IOI typically takes place in late August, early September, and lasts for approximately one week. The week consists of a series of ceremonies, socials, practice rounds, and of course, the actual competition. The actual competition consists of three-days of questions, where contestants have 5 hours to solve 3 complex problems.

After questions are released at the beginning of the day, teams must begin coding their solutions in C++, and upon submission, the file must be smaller than 50 KiB, and the evaluation server must be able to compile it in less than 10 seconds and at most 512 MiB of memory. Teams can submit up to 50 solutions per round, and can submit a solution once per minute to be checked by the grading system.

At the end of the competition, IOI holds an awards ceremony to award the teams that have scored the most points through the three rounds. Both countries and individuals are awarded for their accomplishments with this following structure: “the top 50% of the contestants are awarded medals, such that the relative number of gold : silver : bronze : no medal is approximately 1:2:3:6 (thus 1/12 of the contestants get a gold medal).”

7 Things You Need to Know to Win

1. You need to be an expert in data structures and algorithms

This is essential for solving the complex problems at IOI. A great resource to begin with is Introduction to Algorithms by Cormen, Leiserson, Rivest, and Stein, which is a comprehensive guide for learning algorithms and data structures. Make sure to be able to implement common algorithms like binary search, sorting algorithms, and/or graph algorithms with speed and brevity in code, while being familiar with more advanced and niche algorithms if the question requires it. Check out websites like GeeksforGeeks and Hackerrank, where many examples and practice problems can be found.

2. You need to be proficient in an efficient coding language

With a metric for success being the speed and efficiency of your code, in terms of time spent and space needed, you must be able to code, implement algorithms and come up with solutions in a language that is efficient, such as C++. If you are working on transferring skills from one language to another, practice programming on websites like LeetCode, HackerRank, CodeChef, and TopCoder. As always, start with basic programs to build up to advanced algorithm implementations and practice IOI problems to end off your studying.

3. You need to develop methods and strategies to approach difficult and overwhelming problems

IOI problems are notoriously difficult, comprehensive, and initially overwhelming, but it is key to remember that all problems are possible and proven to be solvable well below the time given. Practice solving algorithmic problems from previous IOIs and other competitions like Google Code Jam. Look for patterns and strategies in the problems to strengthen your skills. Some useful techniques are thinking step-by-step, using examples to generalize the problem, dividing and conquering large problems, starting with a basic solution and optimizing from there. Regular practice is the only way to improve at problem-solving.

4. You need to deeply understand mathematical concepts underlying informatics

A quote from the IOI is that “the hard part isn’t the coding, it is the mathematics underneath it.” Therefore, for any semblance of success, you must hold a mastery over the math of computer science. Many IOI problems incorporate concepts like number theory, combinatorics, geometry, and game theory. Review concepts like prime numbers, factorials, Fibonacci numbers, coordinate geometry, game strategies, probability, and statistics. Mathematics and algorithms are more than deeply connected, so a strong math foundation will boost your computational thinking.

5. You should stay up-to-date with advances in algorithms

New concepts and advancements in computer science often come up in that year’s IOI questions, thus be sure to always be learning to stay updated on the latest algorithms. Read research papers and books on the latest algorithms, which not only allows you get ahead of potential questions, but also reminds you of how the algorithmic knowledge you have can continue to be built upon.

6. You should experiment to Iterate and optimize your solutions

Coming up with a correct solution is not enough. You need to optimize for time and space complexity. Experiment with different approaches and find the most efficient solution. Ask yourself questions like: Can I use a more efficient data structure? Can I cut down the number of operations? Can I apply memorization or dynamic programming? Can I parallelize any part of the solution? Optimization is a key problem-solving skill.

7. You need to practice under timed conditions

To prepare for the time constraints of the actual competition, practice solving problems under timed conditions. Set a timer for 5 hours and work through multiple complex problems. This helps you think quickly on your feet, handle pressure, and manage your time wisely. Take timed practice contests before the event. There are many practice questions available online, such as this link.

If you are looking to do cutting-edge research in STEM and, specifically computer science, then you should consider applying to the Lumiere Research Scholar Program, a selective online high school program for students founded with researchers at Harvard and Oxford. Last year, we had over 2100 students apply for 500 spots in the program! You can find the application form here.

Aaron Zheng is a sophomore at Harvard University, studying Bioengineering. He is passionate about biotechnology, business development, and aiding students to get to college, regardless of background. In his spare time, he looks to read, journal, and explore the world.

Image Source: International Olympiad in Informatics (IOI) logo

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