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Date: 19th July 2020 (Sunday)
Reporting Time: 13:30
Time: 14:00 to 19:00 (5 hours)
Venue: Pui Ching Middle School / Yan Oi Tong Tin Ka Ping Secondary School

* Contestants who do not arrive by the reporting time (13:30) will be disqualified.
* Early leave is not allowed.
* Refreshments will NOT be provided during the test. Contestants may bring their own light refreshments.

Competition Details and Eligibility

Criteria for participating in the TFT
  • An individual medal winner in HKOI 2019/20.
  • Applied for participating in the Team Formation Test during HKOI Final Event registration.
  • A full-time Hong Kong secondary school student at all times between 1st Sept 2019 and 1st June 2020.
International Olympiad in Informatics (IOI) Asia-Pacific Informatics Olympiad (APIO) National Olympiad in Informatics (NOI) International Olympiad of Metropolises (IOM)
Date 13th – 19th September 2020 15th August 2020 At this time, we do not have concrete information about these two competitions. They are listed here only for describing the selection algorithm in case the HKOI Training Team decides to send a team.
Location Online; hosted by Singapore.
*Actual arrangement TBC*
Hosted by Indonesia. Venue: Pui Ching Middle School
Additional Criteria
  • Born on or after 1st July 2000
  • A holder of Hong Kong Permanent Identity Card
  • Born on or after 1st July 2000
  • A holder of Hong Kong Permanent Identity Card
  • Applied for participating in the APIO during HKOI Final Event registration.
  • Born on or after 1st July 2001
  • A holder of Hong Kong Permanent Identity Card
  • Able to read simplified Chinese

Registration and Venue Assignment

HKOI finalists who wish to participate must apply for the Team Formation Test during the Final Event registration. The results of HKOI 2019/20, accompanied with the Team Formation Test application results and venue assignment, will be released in the evening on the HKOI competition day.

A modified version of the HKOI venue assignment algorithm will be used. Let N be the number of students qualified for the Team Formation Test. Then, C1 = 0, C2 = 45 if N ≤ 45. C1 = 20, C2 = 36 if 46 ≤ N ≤ 56. C1 = 20, C2 = 45 if 57 ≤ N ≤ 65. C1 = 40, C2 = 48 otherwise. Contestants’ preference for the HKOI Final Event will be reused.

This year, only students who meet the general criteria listed in the previous section may participate in the Team Formation Test. Walk-in / observers are not allowed.

Prevention Measures

Please refer to the Prevention Measures page.

Download the Health Declaration Form.

Allowed Programming Languages

Students who wish to be considered for a competition may only use the following programming languages. Note that this table does not correspond to the languages the competitions officially allow. Languages not listed below are not allowed.

C++14 Yes Yes Yes Yes
Java (note) Yes Yes No Yes

Using a programming language not allowed for a competition would not immediately render one ineligible for it. However, such submissions would not count towards the ranking for that competition (see below).

All tasks can be solved using C++. For Java, we do not guarantee that a working compiler or IDE can be provided. Also, some tasks may not accept Java solutions.


To be announced

Personal Keyboard and Mouse

For hygiene reasons, contestant are recommended to bring one personal keyboard, one mouse and one mousepad for use in the Test. Wireless keyboards/mice, keyboards/mice that require installation of drivers, and mechanical keyboards fitted with “blue” switches (or equivalent) are not allowed. The size of the mousepad should not exceed 27×22 cm. The adjudicators reserve the right to examine and disallow any keyboard, mouse and mousepad.

Installed Software

To be announced

Submitted programs will be compiled using the compilers and compilation flags specified in the Help page of the Online Judge. The organiser will provide all the necessary hardware and software for the competition. Participants are not allowed to use any of their own resources in the competition.


The paper is only available in English. The paper shall consist of several programming tasks. Each task may carry different points. Each task will be further divided into one or more subtasks. Each subtask may carry different points.

The syllabus shall be the latest version of the IOI syllabus.

Submission of Solutions and Adjudication

Contestants should submit their solution source codes to the Online Judge. The judge will compile the source codes submitted by contestants, and then assess the compiled programs by testing them with a set of data unknown to the contestants and a marking scheme to be determined by the Adjudicators. To score points for a subtask, contestants’ programs must be correct for all test cases in that subtask.

Contestants will receive feedback about their submissions, including type of error first encountered (if any) for each subtask. A contestant’s final score will be the sum of points received from solved or partially-solved subtasks. Contestants may submit at most once per task per 60 seconds, and at most 50 times per task.


During the competition, contestants are allowed to seek clarification on the wordings of the tasks from the Adjudicators by using the competition web interface. Should the condition deem necessary, the clarifications will be announced to all contestants. Clarification related to the solutions will not be entertained.

Any queries about the competition should reach the Chief Adjudicator within 15 minutes after the end of the competition, before exiting the competition venue. The decision of the Adjudicators will be final.


There is a small chance that the score may change due to change of tests, or indeterminacy of the contestant’s submission. Indeterminacy may arise intentionally due to the use of pseudo-random number generators, or unintentionally due to programming bugs or marginal running time. The Hong Kong Olympiad in Informatics Organizing Committee reserves the right to re-evaluate submissions, and the final score will be that yielded by the final evaluation.

Selection Algorithm

One ranking for each external competition will be produced. For each competition:

  • – The ranking will only include the students who commit to attend the competition.
  • – Students will be ordered by the total subtask scores after removing submissions made in disallowed languages.
  • – In case of ties, compare their last submission that resulted in a score increase. The one with the earlier submission time shall rank higher.

Then, the potential delegates will be selected as follows:

Step 1: 4 IOI members

The top 4 students in the IOI ranking will be selected.

Step 2: 36 APIO members

The top 36 students in the APIO ranking will be selected.

For reference only. The following algorithm will be used in case the Training Team decides to send a team.

Step 3a: 2 NOI members

The top 2 students in the NOI ranking will be selected.

Step 3b: 2 NOI members

The top 2 students in the NOI ranking, excluding the selected IOI members and the ones selected in Step 3a, will be selected.

Step 3c: 1 NOI member

If any of the 4 previously selected NOI members is female, then the next student in the NOI ranking, excluding the selected IOI members, will be selected.
Otherwise, the next female student in the NOI ranking, excluding the selected IOI members, will be selected.

Step 3d: 1 NOI member

The top student in the NOI ranking, excluding the selected IOI members and the ones selected in Steps 3a-3c, will be selected.

Step 4: 2 IOM members

The top 2 students in the IOM ranking will be selected.

Other Opportunities

Should there be other learning opportunities, the training team may select members with reference to the TFT and APIO ranking and eligibility criteria.

Required Commitment and Results Announcement

This section does not apply to Asia-Pacific Informatics Olympiad.

The training team will submit the test results, student profiles and comments from the trainers to the Hong Kong Association for Computer Education and the Education Bureau for review and approval. Potential delegates (including backup members) will be requested to sign a Commitment Agreement and Parent’s Consent which must be returned to the Organizing Committee within 7 days in order to be considered further. Withdrawal will not be permitted under any circumstances once the document has been signed.

Potential delegates will be notified of the final selection results. The HKOI Organizing Committee’s decision shall be final.

All selected members are required to attend team training sessions in August.