CEOI Regulations

This is the version of CEOI Regulations approved at the IC meeting during CEOI 2019. Text written in italics contains comments that are not a part of the Regulations.


The Central European Olympiad in Informatics (CEOI) aims to motivate secondary school students in Central Europe to:

  • get more interested in informatics and information technology in general
  • test and prove their competence in solving problems with the help of computers
  • exchange knowledge and experience with other students of similar interest and qualification
  • establish personal contacts with young people of the Central European region

Additionally, the CEOI may:

  • provide training for the students participating in the International Olympiad in Informatics (IOI)
  • initiate discussion and cooperation in informatics education in the secondary schools of the Central European countries

Organization of the CEOI

There are eight CEOI countries: Croatia, Czech Republic, Germany, Hungary, Poland, Romania, Slovakia and Slovenia.

The CEOI is organized by the Ministry of Education or another appropriate institution of one of the CEOI countries. It is expected that the organization rotates among all CEOI countries at an approximately regular basis. The delegations of all CEOI countries must be invited to each CEOI as regular participants. Moreover, the host country may invite guest countries and a second team from the host country, sharing the same team leader.

The International Committee (IC) of the CEOI consists of the eight team leaders and of a representative of the host country who chairs the meetings of the IC. A host who is willing to organize a CEOI in a given year in their country has to announce their intent at least one year before that CEOI (i.e., during the competition days of the previous CEOI). Selection of the next host is made by the IC by a majority vote.

A revision of the CEOI Regulations is adopted by the IC by a 2/3 majority vote.

A new CEOI country can only be adopted by consensus. A country can stop being a CEOI country either by abdicating voluntarily, or by a consensus of all remaining countries.

Delegations and contestant eligibility

A contestant is eligible to compete in the CEOI if and only if they are eligible to compete in the IOI in the same year.

As a reminder, a quote from the current IOI Regulations:

A contestant eligible to compete in IOI is a student who

  • was enrolled in a school at a level not higher than secondary education, in the Country they are representing, for the majority of the period 1 September to 31 December in the year before IOI. Students who are studying abroad may represent the Country of their nationality. Exceptions may be requested through the IC.
  • is not older than twenty years on the 1st of July of the year of IOI.

Each contestant must be selected based on their results in national competitions.

A national delegation consists of up to four eligible contestants, a team leader, and at most one deputy leader. Additionally, a delegation can be accompanied by any number of guests.

Participation fees

The delegations of CEOI countries should cover only the cost of their travel to and from the contest site. The host has to cover all reasonable expenses (notably: accommodation, meals, and excursions) of the delegations of CEOI countries during the event. The host can, and usually does, require the delegations of guest countries and the guests who accompany any delegation to pay participation fees.

Scientific Committee

The Scientific Committee (SC) consists of a chairperson and of a number of experts (SC members) from the host country. It becomes active well before the beginning of the Olympiad and has the task of selecting and preparing proposals for competition tasks, including test data and grading schemes. The SC is expected to prepare at least two backup tasks to be used if some of the proposed tasks are rejected by the GA.

General Assembly

The General Assembly (GA) is composed of the team leaders of all participating countries (including guest countries) and of a representative of the host country who chairs the meetings of the GA. GA meetings are held in English.

Before each contest day, the SC presents the GA the proposal for competition tasks and optionally also short descriptions of proposed model solutions and additional details on the tasks. The GA familiarizes themselves with the tasks and then votes on accepting the proposed tasks (by a simple majority). If the proposal is not accepted, the SC presents one or more backup problems and the GA discusses the options and takes votes until some problem set proposal is accepted. After a problem set is accepted, the GA may still suggest minor changes to the problem statements. These changes should improve the clarity of the problem statement without changing the nature of the task. In particular, these changes cannot imply changes in test data or other related materials prepared by the SC.


At least one month before the competition the host should publish the competition rules for that year and the technical information about hardware and software that will be provided. In particular, the competition rules should define the set of available programming languages, and these should include all languages available at the IOI held in the same year.

The competition consists of two rounds, taking place on different days. In each round the working time is five hours and the contestants are given three problems to solve. Contestants can use the provided programming languages to implement solutions to competition problems. The solutions are evaluated and scored automatically using test data prepared by the SC. During the competition the contestants have the option to submit questions and clarification requests to the SC. All public announcements made by the CEOI authorities to the contestants must also be provided in written form.

The contestants must have the option to use their native language. In particular:

  • The team leaders are responsible for translating the official English version of the problem statements into the native language(s) of their contestants.
  • The contestants may submit their questions addressed to the SC in their native language. The team leaders are responsible for translating such questions into English (and for translating the answer back into the native language, if applicable).

Generally, the contents and the form of the CEOI tasks should be guided by the IOI syllabus.

After the competition, the contestants and team leaders must be given the access to data that will enable them to verify whether their solutions were evaluated correctly. If a team leader does not accept the results of the evaluation and cannot come to an agreement with the SC, the team leader can submit an appeal. The appeal and all relevant data (anonymised if possible) must be presented to the GA by the chair of the SC or the chair of the GA. The GA then takes the final decision on the appeal.

Results and Prizes

About 50% of all contestants (including guest countries and the second team of the host country, if present) should receive medals. The proportion of these gold, silver and bronze medals should be approximately 1:2:3. Given these expectations, the General Assembly will determine the minimum scores for the gold, silver and bronze medals.

Each contestant should receive a certificate of participation. The medals, certificates and other prizes should be given to the contestants at the official closing ceremony.