This week, the Central European Olympiad in Informatics 2023 (CEOI 2023) is going to take place! CEOI is a programming contest for secondary school students from countries in Central Europe. Around 50 contestants from Croatia, the Czech Republic, Germany, Hungary, Poland, Romania, Slovakia, Slovenia, and our guest countries Israel, Switzerland, and Ukraine will compete against each other, solving difficult problems of algorithmic nature. Each participating country sends 4 contestants from their national olympiads which take place in the months beforehand.

The contest consists of two days, Tuesday and Thursday, on each of which the contestants have 5 hours to solve 3 problems of varying difficulty. Each problem is worth 100 points that are distributed into multiple subtasks with different constraints that allow the participants to earn partial scores.

CEOI 2023 is hosted in Magdeburg, state capital of Saxony-Anhalt and among the most historical cities of Germany. There will be a live scoreboard during the two competition days, and we will host an online mirror around a week after CEOI. For more information about the contest, visit the official website at ceoi2023.de.

We wish all CEOI contestants an enjoyable contest and a good time in Magdeburg!

-- CEOI 2023 committee

Update: The first competition day has just started. The scoreboard can be found here.

Update: The contestants are right now competiting in the second contest. As before, the scoreboard can be found here.

Update: CEOI 2023 has just concluded. With the medals awarded in the closing ceremony yesterday (see here for the final ranking), the teams are now on their way back home. We hope that everyone enjoyed the contests. Congratulations again to all participants, all medalists, and in particular to the overall winner of CEOI 2023, lucaperju!

Also, we are happy to invite you to participate in the online mirror of CEOI 2023 on Friday, August 25, 2023 at 7:00 UTC and Saturday, August 26, 2023 at 7:00 UTC! The mirror will be held on CMS which was also used for the official contest. We will open the registration closer to the start of the mirror.

Update: The online mirror is now configured! Since this was requested, the mirror will now have a longer timeframe during which you can participate: for both contests, you can pick an arbitrary 5 hour timeslot between Wednesday, August 23, 2023 at 0:00 UTC and Sunday, August 27, 2023 at 23:59 UTC to participate. Note that the mirror will not be permanently monitored. Also, please refrain from discussing the tasks publicly until Monday so that everyone can enjoy the mirror without knowing the tasks in advance.

To register for the contests, go to the contest system, select the contest that you want to participate in, and register an account (it's not necessary to enter an email). If you want to participate in both contests, you afterwards have to go to the other contest, click on the registration link and enter your account details in the "Join contest" tab. Then, starting from Wednesday, when you log into the system you can start your 5 hour timeslot whenever you want.

Final Update: As the online mirror nears its end, we hope that you have enjoyed the problems, or that you still will if you plan to use the last few hours to take part. Once the contests are over, there will be an analysis mode for about a week for both contests where you can analyse your solutions and try to improve them. We will also upload the problems, the test data, and some spoilers for all problems to the official website in the near future.

With this we say goodbye and look forward to CEOI 2024 in the Czech Republic!

This weekend, the Baltic Olympiad in Informatics 2022 (BOI 2022) is going to take place! BOI is a programming contest for secondary school students from countries around or close to the Baltic sea. This year, around 70 contestants from Denmark, Estonia, Finland, Germany, Iceland, Latvia, Lithuania, Norway, Poland, Sweden and our guest countries Israel and Ukraine will compete against each other, solving difficult problems of algorithmic nature. Each participating country sends 6 contestants from their national olympiads which take place in the months beforehand.

The contest consists of two days, Saturday and Sunday, on each of which the contestants have 5 hours to solve 3 problems of varying difficulty. Each problem is worth 100 points that are distributed into multiple subtasks with different constraints that allow the participants to earn partial scores. During the contest, each participant receives the verdict of the execution of their solutions on all tests.

While BOI 2020 and BOI 2021 were virtual only, we are excited to meet most BOI contestants this year in-person! BOI 2022 is hosted onsite in the beautiful city of Lübeck, a historical German town on the Baltic Sea, member of the „Hanse“ trade union of cities. Only the contestants from Israel participate from their own country in a proctored online setting. For more information about the contest, visit the official website at boi2022.de.

Furthermore, we hope to be able to host an online mirror of BOI 2022 for all those who are waiting for a sequel to the story of the BOI contestant turned art thief. However, the online mirror will be held at least one week later than the actual contest. We will publish more details about the mirror in the coming week.

We wish all BOI contestants an enjoyable onsite contest and hope that the coming olympiads can be hosted in-person, too!

-- BOI 2022 committee

Update: The official contests are now over. Congratulations again to all the medalists and in particular to the overall winner of BOI 2022, antekb! In the end, 36 medals were awarded to official contestants, with the guest delegation of Ukraine winning 4 out of 7 gold medals. We will publish the official results of this year's BOI after the online mirror.

Speaking of the online mirror, we are happy to invite you to participate in the online mirror of BOI 2022 on Saturday, May 7, 2022 at 8:00 UTC and Sunday, May 8, 2022 at 8:00 UTC! The mirror will be held on CMS which was also used for the official contest. To register for the online mirror, visit contest.boi2022.uni-luebeck.de. You need to register there, before participating.

Update: The official results are now published here, but without the task-wise scores for now. They will be added after the online mirror is over. We hope you enjoy the problems in the mirror tomorrow!

Update: The online mirror of the first day is over! We hope you liked the problems. You can see the scoreboard of the online mirror here, and you can compare your results with the results of the official contestants on this scoreboard.

Note: If you want to know how the story of the hypothetical art heist continues, we highly recommend that you also participate in the online mirror of day 2. However, note that if you have already created an account for day 1, you still have to join the mirror of day 2. This works by going to the registration page and using the option "Join contest" there.

Update: The mirror of day 2 is now over, too. We hope that the tasks, especially communication, were a challenge for you ;-) You can see the combined results of day 1 and day 2 on the same scoreboards as before, the ranking of the online mirror here and the official results here. We will publish all tasks together with their spoilers and the test data in coming days on the official website.

Final Update: Sorry that it took so long, but we have now finally added the tasks, their spoilers and the test data to the official website. We hope you enjoyed the tasks, and we are looking forward to next year's BOI in Denmark!

The year is 2021. Like every year, contestants from all of the baltic countries meet for the Baltic Olympiad in Informatics. Well, not entirely... One small virus still holds the entire world under its spell. And life is not easy for BOI contestants who have to participate remotely from their own homes...

This weekend, the Baltic Olympiad in Informatics 2021 (BOI 2021) is going to take place! BOI is a programming contest for secondary school students from countries around or close to the Baltic sea. This year, around 60 contestants from Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Norway, Poland, Sweden and our guest countries Israel and Ukraine will compete against each other, solving difficult problems of algorithmic nature. Each participating country sends 6 contestants from their national olympiads which take place in the months beforehand.

The contest consists of two days, Saturday and Sunday, on each of which the contestants have 5 hours to solve 3 problems of varying difficulty. Each problem is worth 100 points that are distributed into multiple subtasks with different constraints that allow the participants to earn partial scores. During the contest, each participant receives the verdict of the execution of his/her solutions on all tests.

BOI 2021 was planned to be hosted in the beautiful city of Lübeck, a historical German town on the Baltic Sea, member of the „Hanse“ trade union of cities. Now, due to the Corona pandemic, BOI is run for the second year in a row as a virtual event only with contestants participating from their own countries in a proctored online setting. Next year, BOI 2022 is hopefully really going to take place in Lübeck. For more information about the contest, visit the official website at boi2021.de.

Furthermore, if you want to experience the struggle of a BOI contestant for a medal firsthand, we are happy to invite you to participate in an online mirror of BOI 2021! The online mirror will be held on Saturday, April 24, 2020 at 14:00 UTC and Sunday, April 25, 2020 at 14:00 UTC, the same days as the official contest, but with 6 hours delay. The mirror will be held on CMS which is also used for the official contest. To register for the online mirror, visit opencontest.boi2021.uni-luebeck.de. You need to register there, before participating.

We wish everyone and in particular all BOI contestants an enjoyable contest despite these challenging circumstances!

-- BOI 2021 committee

Update: The first contest is over! You can find the results of the intense competition on the scoreboard here.

Update: We hope that all participants in the online mirror enjoyed the problems! Standings can be found here. And don't miss the mirror of the second day tomorrow if you want to know how the story about the BOI participant who turned art thief continues...

Update: And that's it! The official contest of the second day is over, too. Congratulations to all participants on their performances! We hope that everyone enjoyed the problems. The combined ranking of both days can be found on the same scoreboard as before. (And of course, the mirror of day 2 will start in less than an hour...)

Final Update: After the committee took a small break to catch up on the sleep missed over the last weekend, we finally got around to update the official website with all the information that was still missing. Firstly, we have added the official results of this year's BOI. Congratulations again to all the medalists and in particular to the overall winner of BOI 2021, almogwald! Also, you can now find all the tasks on the website, including spoilers and test data.

Finally, we were really impressed to see the strong competition in this year's contest. While not being able to meet anyone in person, we hope that we will see some of participants again next year in Lübeck. Until then: Auf Wiedersehen!