Update on 14th July 2020: The Team Formation Test (Round 1) will be held online on 19th July 2020 (Sunday).

Update on 15th July 2020: Detailed contest procedure is now available.

Update on 17th July 2020: There are a few clarifications and amendments in the Procedures page

All eligible students are required to re-register by 16th July. See details below.

Please visit this page frequently for rule updates.

Supplemental Documents

Students should also read the following documents. They form part of the rules.

Team Formation Test 2020 (Round 1) Procedures
Team Formation Test 2020 (Round 1) Privacy and Data Policy


Date: 19th July 2020 (Sunday)
Format: Online with invigilation

13:00 – 13:30 Reporting Time. Contestants who do not report by 13:30 will be disqualified.
13:30 – 13:50 Preparation
13:50 – 14:00 Paper 1 – Waiting Room
14:00 – 16:15 Paper 1 – Contest time (2 Hours 15 Mins)
16:15 – 16:20 Paper 1 – After End
16:20 – 16:35 Break Time
16:35 – 16:45 Paper 2 – Waiting Room
16:45 – 19:00 Paper 2 – Contest Time (2 Hours 15 Mins)
19:00 – 19:05 Paper 2 – After End

Competition Details and Eligibility

Criteria for participating in the TFT
  • A finalist in HKOI 2019/20 (Any Group).
  • 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. Compete from Home
Website ioi2020.sg apio2020.id www.noi.cn
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


HKOI finalists who wish to participate in the Team Formation Test (Round 1) must register between 12:00 15th July 2020 and 23:59 16th July 2020. Students who do not register by the deadline shall forfeit their eligibility. There are no consequences if the student does not attend the Test / APIO after registration.

Eligible students should log into HKOI Online Judge using their existing account / the finalist practice account provided to them through their schools. Information about the accounts, titled “[Join HKOI] Hong Kong Olympiad in Informatics 2019/20”, have been emailed to the contact persons listed in the HKOI Nomination Form on 20th November 2019.

Enter HKOI Online Judge Contests page

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.

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.


Each contestant should use their own computer (Client Computer) to connect to the competition workstation (Virtual Machine) provided by the organiser.

Client Computer

To connect to the Virtual Machine and to support invigilation, the Client Computer should meet the following specifications.

Minimum requirements Recommended Specification Restrictions
Operating System Desktop computer (Windows / MacOS / Linux) or
Laptop Computer (Windows / MacOS / Linux / Chromebook)
Windows / Linux / Chromebook. MacOS is not recommended due to key mapping differences. Each contestant may only use one computer
Browser Chrome Other browsers are not recommended
Display Built-in or External
1920×1080 Each contestant may only use one display. If the contestant connects an external display to a laptop, the built-in display must be turned off. The Virtual Machine’s maximum resolution is 1920×1080
Communication Webcam (built-in or peripheral) + Microphone (built-in or peripheral) + Speakers (built-in or peripheral) or
A camera-equipped mobile phone with Google Meet installed
Webcam + Microphone + Speakers and a camera-equipped mobile phone with Google Meet installed (for redundancy) Headphones are not allowed
Input Devices Keyboard, mouse / trackpad Keyboard and mouse. Trackpad is not recommend. Macro / calculation functions must be disabled.

Virtual Machine


Virtualization: Amazon AWS “c5.xlarge”
CPU: Intel Xeon Platinum 8275CL “Cascade Lake” @ 3.0 GHz up to 3.6 GHz all core turbo. 2 cores 4 threads (exposed to the VM as 4 CPUs)
Memory: 8 GB + 2 GB swap
Disk space: At least 1.5 GB free space on local disk + 100 MB network drive quota.
Display: 1920×1080 maximum

Installed Software

Operating System: Debian 10 “Buster”
Display Manager: XFCE4
Google Chrome
Visual Studio Code with the following extensions: C/C++ v0.28.3, Language Support for Java by Red Hat v0.64.1, Code Runner v0.11.0
G++ 8.3.0 (Debian 8.3.0-6)
OpenJDK Runtime Environment (AdoptOpenJDK) (build 1.8.0_252-b09)

Submitted programs will be compiled using the compilers and compilation flags specified in the Help page of the Online Judge. Participants are not allowed to use any of their own resources in the competition.


The Team Formation Test 2020 (Round 1) consists of two papers. Each of them will be 2 hour and 15 minutes long. There is a 15-minute break between the two papers. The score of this Round 1 will be the sum of the scores of the two papers.

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 HKOI Senior Group 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 assigned invigilator within 5 minutes after the end of each paper, before leaving the seat or disconnecting from the Google Meet meeting. 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

NOI and IOM are included here for reference only. The following algorithm will be used in case the Training Team decides to send a team.

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

  • The ranking will only include the students who are eligible for the competition.
  • – The ranking will only include the students who commit to attend the competition. (Not required to be shortlisted for the IOI/IOM)
  • – Students will be ordered by the total subtask scores after removing submissions made in disallowed languages. (e.g. Java for NOI)
  • – In case of ties, compare their last submission in Paper 2 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: 15 IOI/IOM shortlist members

The results of this Team Formation Test (Round 1) would serve as a reference for selecting IOI/IOM members. Top 15 students in the IOI ranking will be invited to additional round(s) scheduled to be held in late July – August.

Step 2: 60 APIO members

The top 60 students in the APIO ranking will be selected.

Step 3a: 4 NOI members

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

Step 3b: 1 NOI member

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

Step 3c: 1 NOI member

The top student in the NOI ranking, excluding the ones selected in Steps 3a-3b, 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.