1.1. These Competition Rules cover Competition Procedures and Judging Procedures. This draft may
be revised to address omissions or inconsistencies but will not change substantially. The final
version was presented at the first GA meeting of EJOI 2017 .
1.2. The terminology used
in this document is from IOI Regulations.
1.3. Delegation Leaders have the
responsibility of ensuring that all members of their delegation fully understand these rules
and abide by them.
2. Competition Schedule
There will be two competition days. On each day contestants will be given three tasks to
complete in four hours.
organization of the eJOI in year n is the responsibility of the Host Country for eJOI'n. A
Host Country consists of the responsible Ministry(ies), Institution(s), and/or
Corporation(s) in that Country.
3.2 Each participating Country is represented by a
National Delegation; all members of a National Delegation represent one Country. A National
Delegation is headed by a Delegation Leader, includes a team of one to four Contestants and,
if there is more than one Contestant, may include a Deputy Leader.
3.4 The Deputy
Leader can act as a replacement for the Delegation Leader in all situations and may assist
their Delegation Leader in all their duties.
3.5 A Contestant is a student who
1. 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
eJOI'n. Students who are studying abroad may represent the Country of their nationality.
Exceptions may be requested through the IC.
2. Contestants of 2020 year should be born after 31st of December 2004
4.1. Each contestant will receive the official English version of the tasks in an envelope
on each contest day. For those contestants who requested translation of the tasks, an
additional version of the tasks in the requested languages will be provided in the same
envelope along with the English version
4.2. In addition, each contestant will have online access to the official English version of
tasks and all task translations in electronic format (PDF).
4.3. The number and kind of files that the contestant must submit as a solution (for
example, "source code of the program in a text file") will be specified in the task statement.
4.4. Direct access to any file, excluding standard input and standard output, is forbidden.
In some tasks reading from file and writing in file this could be not necessary at all
because data will be exchanged through the interfaces specified in the task statement
4.5. Each task will be checked on set of single test cases or/and groups of test cases with
specific properties (subtasks), each worth a portion of the total points. Points for subtask
will be assigned only when all test cases of the subtask are solved.
4.6. Time limit for a single test case and memory limit will be specified for every task.
When few tests are grouped in a subtask then time limit is applied for each test case in the
group separately. The memory limit is on the overall memory usage including executable code
size, stack, etc. In general, time and memory limits will be generous.
4.7. All necessary files regarding the statement of a task as well as electronic documentation
or reference manuals will be provided through the grading system.
5. Practice Session
5.1. There will be a two-hour Practice Session prior to the first competition day, to
contestants with the grading system. The practice tasks will be published before the eJOI.
6.1. In order to protect the confidentiality of the tasks, all direct and indirect contacts and
contestants and people attending GA are prohibited between the moment where tasks for a
competition day are presented
to the members of the GA and the end of the four-hour round on the following day. During this
period the contestants
are not allowed to communicate by any means, direct or indirect, with any member of the GA or
anyone who knows the tasks.
6.2. The GA members are not allowed to communicate any task-related information to anyone who
may not attend GA meetings.
The contestants, the GA members and anyone else who has had access to the tasks must obey any
instructions which restrict
their access to specific parts of the eJOI venue.
6.3. If a contestant violates the quarantine, he or she can be subject to disqualification.
6.4. If some other person associated with a national delegation violates the quarantine, then
all contestants of that
delegation may be subject to disqualification.
7. Competition Equipment and Environment
7.1. Competition equipment and environment (OS, IDE, reference manuals, usage of file system
will be announced on the web page of the current eJOI under the link Contest Environment.
8.1. In the competition room, working paper and writing tools will be provided. On the
contestants may not bring anything into the competition rooms, except for the following items
under the provision
that they cannot transmit or store any data in electronic or printed format (other than the
purpose for which they
have been designed):
● reasonable jewelry
● keyboards (without wireless and/or calculation functions)
● small mascots
● English dictionaries
● mechanical watches
8.2. If a contestant wants to bring a keyboard, small mascots or English dictionaries to the
competition, these must
be submitted to the technical staff during the practice competition day. Any of these will be
checked and, if cleared,
will be given to the contestant in the first competition day. After the first competition day,
the contestant must
leave these items on his or her workstation if he or she wants to use them during the second
competition day. Once again
these will be checked and, if cleared, will be given to the contestant in the second competition
day. After the second
competition day the contestant must take all of these items with him or her.
8.3. Any attempt to bring any other item into the competition room will be considered cheating.
In particular, during
competition rounds it is strictly prohibited to bring:
● any computing equipment (e.g. calculators, laptops, tablets, smart watches, activity tracker,
and not presented in advance keyboards)
● any books, manuals, written or printed materials
● any data storage medium (e.g., CD-ROMs, USB drives, flash cards, micro-drives)
● any communication devices (e.g., mobile phones, radios of any sort)
9. Competition and Grading
9.1. All contestants must wear their ID badges during the competition.
9.2. Each contestant will have a pre-assigned workstation. The workstations have network access to the grading system.
9.3. Contestants should be in their seats at least 5 minutes prior to the start of the competition. Contestants must
find their assigned computer, sit down, and wait for the competition to begin without touching anything (such as
keyboards, mice, pen or paper).
9.4. Contestants must submit their solutions for tasks by using the grading system.
9.5. During the competition, contestants may submit written questions concerning any ambiguities or items needing
clarification in the competition tasks. Questions and comments must be submitted through the grading system or on the
provided Clarification Request Forms, expressed either in the contestant's native language or in English. If required,
delegation leaders will translate their contestants' questions into English after they are submitted and before they
are sent to the Scientific Committee. The Scientific Committee will respond to every question submitted by the
contestants during the competition. Since this might take some time, contestants should continue working while
waiting for the answer to their questions.
9.6. Contestants should phrase their questions so that a yes/no answer will be meaningful.
9.7. Questions will be answered with one of the following without any translation (so the contestant have to know their meaning):
● "ANSWERED IN TASK DESCRIPTION (EXPLICITLY OR IMPLICITLY)" - The task description contains sufficient information.
The contestant should read it again carefully.
● "INVALID QUESTION" - The question is most likely not phrased so that a yes/no answer would be meaningful. The
contestant is encouraged to rephrase the question.
● "NO COMMENT" - The contestant is asking for information that the Scientific Committee cannot give
9.8. There is no restriction on the number of times a program may be edited, compiled, and run on the workstation.
9.9. Grading and evaluation take place on the grading system, which provides a same execution environment to that of
the contestant workstation. Grading workstation will have the same hardware and software configuration as contestants'
workstations (without programs for monitoring and the grading system)
9.10. To avoid overloading the grading system, there are two restrictions on the number of submissions:
● Contestants may submit a solution to each task at most once per 30 seconds. This restriction is removed in the last 15 minutes of the contest.
● Contestants may submit at most 100 solutions for each task.
9.11. Each submitted source program must be written in C++ or Java, it must be smaller than 256 KB, the evaluation server
must be able to compile it in less than 10 seconds and at most 256 MB of memory.
9.12. Contestants can use the grading system to view the status of their submissions and get a short report on the
compilation errors of their source code.
9.13. Full feedback will be available for some tasks, indicating whether each single test case or subtask has been
solved. For the other tasks a partial feedback (for at least one test case) will be given.
9.14. As Java Virtual Machine uses multiple threads internally, using multiple threads is allowed in all programming
languages. Note that the running time of the submission will be counted as a sum of running times of all threads.
E.g. if there were two threads running for 5 seconds each (thus, the program finishes in 5 seconds), then the running
time of the submission will be 10 seconds.
9.15. The final score for each subtask will be the maximum score of this subtask across all submissions. The score for
each task will be sum of scores for its subtasks.
9.16. If a subtask is not solved, then the grading system will give the feedback for the first input scenario, which
was not solved correctly. The feedback will contain the input scenario number and the type of error, details are
described in PCMS Guide.
9.17. It should be noted that the score reported in the full feedback is only provisional. There are two ways how this
score may change after it has been reported to the contestant:
● Due to a successful appeal after the contest.
● In some cases, the contestants' submissions may be re-evaluated. This re-evaluation may sometimes lead to a different
total score. (E.g., if a solution behaves nondeterministically or runs very close to the time or memory limit.) In such
cases, the final score for the submission is the score for its latest re-evaluation. This change in scoring cannot be
appealed. Note that the final score for each task is still the maximum score over all submissions.
9.18. Contestants may ask the support staff for assistance at any time. The staff members will not answer questions
about the competition tasks, but will deliver Clarification Request Forms, help locate toilets and refreshments, and
assist with computer and network problems. The only manner in which contestants are allowed to access the network is
via the grading system: even running a single "ping" command is strictly prohibited and may lead to disqualification.
9.19. Contestants should never attempt to fix or debug or even check computer or network problems themselves; instead,
they should ask for assistance.
9.20. Three warnings will be given at 30 minutes, 15 minutes, and 5 minutes before the end of the competition. Each
warning will be given by an audible signal. The end of the competition will be announced both verbally and by an
audible signal. At the announcement ending the competition, contestants must immediately stop working and wait at their
desks without touching the computers or anything on their desks. An additional announcement will be made instructing them
to leave their tables and exit the competition room.
9.21. At the end of the first competition, any previously submitted items a contestant would like to use during the
second competition should be left . All other items should be taken out of the competition hall. At the end of the
second competition, contestants should remove all personal items including their mascots and dictionaries or any other
previously submitted item; nothing should be left behind.
10.1. Contestants must use only the workstation and account assigned to them on each competition day. In particular contestants must not:
● attempt to submit illegal programs as discussed above, nor try to tamper with or compromise the grading system
● attempt to gain access to root or any account other than the one assigned to them
● attempt to store information in any part of the file system other than specified by Contest Environment
● touch any workstation other than the one assigned to them
● attempt to access any machine on the network or the Internet, other than to submit tasks and view submission
results through the grading system
● attempt to alter the boot sequence of any workstation
● communicate with other people during the competition, other than the staff and/or Scientific Committee members.
All of the above actions are considered cheating and may result in disqualification.
11. Appeal Process
11.1. Provisional grades, based on tests, are available immediately to competitors. In the event of an error with the
test data, the Scientific Committee will attempt to, but is not obligated to follow the following process:
● Every attempt will be made to fix test data and regrade all solutions as quickly as possible.
● Additional test data may be added only when the grading data does not meet the intention of the Scientific Committee from before the contest.
● Late detections of issues, especially during the last 2 hours of the contest, may be grounds for extending the length of the contest.
11.2. The hidden test data will be made available electronically in the competition area during the scheduled time after
second competition day. Contestants and team leaders may use the contestant's workstations to verify that the grades are
11.3. A Team Leader may file an appeal by completing an Appeal Form and submitting it to the Scientific Committee at
least 30 minutes prior to the final GA meeting of that competition day. The GA will be informed of where Appeal Forms
can be collected, and where they can submit them to the Scientific Committee. Every appeal will be reviewed by the
Scientific Committee and the Team Leader will be notified of the committee's decision. All appeals and their
disposition will be summarized at the final GA meeting of that competition day.
11.4. In the event that every submission of a task should be re-graded and re-scored as a consequence of an accepted
appeal, note that re-scoring may result in a higher or lower score for any contestant. Should anyone's score change
after grading results have been published, new results will be published again. Score changes resulting from this are