International Olympiad in Informatics
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/bf/InternationalOlympiadInInformatics.png/220px-InternationalOlympiadInInformatics.png)
The International Olympiad in Informatics (IOI) is an annual competitive programming competition and one of the International Science Olympiads for secondary school students. The first IOI was held in 1989 in Pravetz, Bulgaria. It is the second largest science olympiad, after the International Mathematical Olympiad, in terms of number of participating countries (88 at IOI 2022). Each country sends a team of up to four students, plus one team leader, one deputy leader, and guests.
The contest consists of two days of computer programming/coding and problem-solving of algorithmic nature. To deal with problems involving very large amounts of data, it is necessary to have not only programmers, "but also creative coders, who can dream up what it is that the programmers need to tell the computer to do. The hard part isn't the programming, but the mathematics underneath it."[1]
Students in each country are selected for their country's team through national computing contests. Students at the IOI compete on an individual basis. There is no official team ranking.
The IOI is one of the most prestigious computer science competitions in the world. UNESCO and IFIP are patrons.
Competition structure and participation
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/98/IOI_2006_competition_room.png/220px-IOI_2006_competition_room.png)
On each of the two competition days, the competitors are typically given three problems which they have to solve in five hours. Each student works on their own to solve the problems with no outside help, specifically no communication with other contestants, books, web access etc. Contestants are typically allowed to bring no programable wired keyboards and mice.[2] Usually to solve a task the contestant has to write a computer program (in C++) and submit it before the five-hour competition time ends. The program is graded based on secret test data. Since IOI 2010, tasks are divided into subtasks with graduated difficulty, and points are awarded only when all tests for a particular subtask yield correct results, within specific time and memory limits. In some cases, the contestant's program has to interact with a secret computer library, which allows problems where the input is not fixed, but depends on the program's actions – for example in game problems (a.k.a interactive problems). Another type of problem has the inputs publicly available, for these, the contestants have to submit an output file instead of a program, and it is up to them whether they obtain the output files by writing a program (possibly exploiting special characteristics of the input), or by hand, or by a combination of these means. Pascal has been removed as an available programming language as of 2019.[3]:11
IOI 2010 for the first time had a live web scoreboard with real-time provisional results. Submissions will be scored as soon as possible during the contest, and the results posted. Contestants will be aware of their scores, but not others', and may resubmit to improve their scores. Starting from 2012, IOI has been using the Contest Management System (CMS) for developing and monitoring the contest.[4]
The scores from the two competition days and all problems are summed up separately for each contestant. Medals are awarded depending on their relative total score. The top 50% of the contestants are awarded medals, such that the relative number of gold : silver : bronze : no medal is approximately 1:2:3:6 (thus 1/12 of the contestants get a gold medal).
Prior to IOI 2010, students who did not receive medals did not have their scores published, although the scores of students who did not receive medals are still not available in the official results, they are known from the live web scoreboard. In IOI 2012 the top 3 nations ranked by aggregate score (Russia, China and USA) were subsequently awarded during the closing ceremony.
Analysis of female performance shows 77.9% of women obtain no medal, while 49.2% of men obtain no medal. "The average female participation was 4.4% in 1989–1994 and 2.2% in 1996–2014." It also suggests much higher participation of women on the national level, claiming sometimes double-digit percentages in total participation on the first stage.[5] President of the IOI (2011-2014), Richard Forster, says the competition has difficulty attracting women and that in spite of trying to solve it, "none of us have hit on quite what the problem is, let alone the solution."[1] The European Girls’ Olympiad in Informatics (EGOI), which was first held in 2021 was started with the goal to increscent female participants at IOI and other Informatics Olympiads.[6]
In IOI 2017 held in Iran, due to not being able to participate in Iran, the Israeli students participated in an offsite competition organized by IOI in Russia.[3]:11 Due to visa issues, the full USA team was unable to attend, although one contestant Zhezheng Luo[7] was able to attend by traveling with the Chinese team[8] and winning gold medal and 3rd place in standings.[9]
In IOI 2019 held in Azerbaijan, the Armenia team did not participate due to the dispute between the two countries, despite the guarantees provided[10] and official invitation letter sent by the host Azerbaijan.
Due to the COVID-19 pandemic, both the IOI 2020 and IOI 2021, originally scheduled to be hosted by Singapore, were held as online contests. The IOI 2022, hosted by Indonesia, was held as a hybrid event, with around 25% of the contestants participating online.[11]
Members
[edit]Albania
Algeria
Argentina
Armenia
Australia
Austria
Azerbaijan
Bangladesh
Belarus
Belgium
Bolivia
Bosnia and Herzegovina
Brazil
Bulgaria
Canada
Chile
China
Colombia
Croatia
Cuba
Cyprus
Czech Republic
Denmark
Dominican Republic
Ecuador
Egypt
El Salvador
Estonia
Finland
France
Georgia
Germany
Greece
Hong Kong
Hungary
Iceland
India
Indonesia
Iran
Ireland
Israel
Italy
Japan
Jordan
Kazakhstan
Kyrgyzstan
Latvia
Libya
Lithuania
Luxembourg
Macau
Malaysia
Mexico
Moldova
Mongolia
Montenegro
Morocco
Netherlands
New Zealand
Nigeria
North Macedonia
Norway
Pakistan
Palestine
Peru
Philippines
Poland
Portugal
Romania
Russia
Rwanda
Saudi Arabia
Serbia
Singapore
Slovakia
Slovenia
South Africa
South Korea
Spain
Sri Lanka
Sweden
Switzerland
Syria
Taiwan
Tajikistan
Thailand
Tunisia
Turkey
Turkmenistan
Ukraine
United Kingdom
United States
Uzbekistan
Venezuela
Vietnam
Former members
[edit]Summary
[edit]Number | Year | Dates | Host country | Host city | Results | Website |
---|---|---|---|---|---|---|
1 | 1989 | May 16–19 | ![]() |
Pravetz | [12] | |
2 | 1990 | July 15–21 | ![]() |
Minsk | [13] | |
3 | 1991 | May 19–25 | ![]() |
Athens | [14] | |
4 | 1992 | July 11–21 | ![]() |
Bonn | [15] | |
5 | 1993 | October 16–25 | ![]() |
Mendoza | [16] | [17] |
6 | 1994 | July 3–10 | ![]() |
Haninge | [18] | [19] |
7 | 1995 | June 26 – July 3 | ![]() |
Eindhoven | [20] | |
8 | 1996 | July 25 – August 2 | ![]() |
Veszprém | [21] | |
9 | 1997 | November 30 – December 7 | ![]() |
Cape Town | [22] | |
10 | 1998 | September 5–12 | ![]() |
Setúbal | [23] | |
11 | 1999 | October 9–16 | ![]() |
Antalya-Belek | [24] | |
12 | 2000 | September 23–30 | ![]() |
Beijing | [25] | |
13 | 2001 | July 14–21 | ![]() |
Tampere | [26] | |
14 | 2002 | August 18–25 | ![]() |
Yong-In | [27] | |
15 | 2003 | August 16–23 | ![]() |
Kenosha, Wisconsin | [28] | |
16 | 2004 | September 11–18 | ![]() |
Athens | [29] | |
17 | 2005 | August 18–25 | ![]() |
Nowy Sącz | [30] | [31] |
18 | 2006 | August 13–20 | ![]() |
Mérida, Yucatán | [32] | |
19 | 2007 | August 15–22 | ![]() |
Zagreb | [33] | [34] |
20 | 2008 | August 16–23 | ![]() |
Cairo | [35] | |
21 | 2009 | August 8–15 | ![]() |
Plovdiv | [36] | [37] |
22 | 2010 | August 14–21 | ![]() |
Waterloo, Ontario | [38] | [39] |
23 | 2011 | July 22–29 | ![]() |
Pattaya | [40] | [41] |
24 | 2012 | September 23–30 | ![]() |
Sirmione and Montichiari | [42] | [43] |
25 | 2013 | July 6–13 | ![]() |
Brisbane | [44] | [45] |
26 | 2014 | July 13–20 | ![]() |
Taipei | [46] | [47] |
27 | 2015 | July 26 – August 2 | ![]() |
Almaty | [48] | [49] |
28 | 2016 | August 12–19 | ![]() |
Kazan | [50] | [51] |
29 | 2017 | July 28 – August 4 | ![]() |
Tehran | [52] | [53] |
30 | 2018 | September 1–8 | ![]() |
Tsukuba | [54] | [55] |
31 | 2019 | August 4–11 | ![]() |
Baku | [56] | [57] |
32 | 2020 | September 13–19a | ![]() |
online | [58] | [59] |
33 | 2021 | June 19–25 | ![]() |
online | [60] | [61] |
34 | 2022 | August 7–15 | ![]() |
Yogyakarta | [62] | [63] |
35 | 2023 | August 28 – September 4 | ![]() |
Szeged | [64] | [65] |
36 | 2024 | September 1–8 | ![]() |
Alexandria | [66] | |
37 | 2025 | ![]() |
La Paz | [67] | ||
38 | 2026 | ![]() |
All-time medal table
[edit]Rank | Nation | Gold | Silver | Bronze | Total |
---|---|---|---|---|---|
1 | ![]() | 100 | 27 | 12 | 139 |
2 | ![]() | 68 | 40 | 12 | 120 |
3 | ![]() | 65 | 38 | 16 | 119 |
4 | ![]() | 48 | 47 | 28 | 123 |
5 | ![]() | 42 | 50 | 35 | 127 |
6 | ![]() | 35 | 28 | 10 | 73 |
7 | ![]() | 33 | 58 | 36 | 127 |
8 | ![]() | 31 | 65 | 23 | 119 |
9 | ![]() | 27 | 51 | 45 | 123 |
10 | ![]() | 25 | 61 | 27 | 113 |
Totals (10 entries) | 474 | 465 | 244 | 1,183 |
Multiple IOI winners
[edit]The following is a list of the top performers in the history of the IOI.[68] The P sign indicates a perfect score, a rare achievement in IOI history. The U sign indicates an unofficial participation, where a contestant participated in a host's second team. Also, first (I), second (II) and third (III) places among gold medalists are indicated where appropriate.
Name | Team | Years | ||||||
---|---|---|---|---|---|---|---|---|
Gennady Korotkevich | Belarus | G(II) 2012 | GP(I) 2011 | G(I) 2010 | G(I) 2009 | G 2008 | G 2007 | S 2006 |
Bruce Merry | South Africa | G 2001 | G 2000 | S 1999 | B 1998 | B 1997 | B 1996 | |
Rumen Hristov | Bulgaria | G 2012 | G 2011 | G(II) 2010 | S 2009 | S 2008 | ||
Hristo Venev | Bulgaria | G 2016 | G 2015 | G 2014 | G 2013 | S 2012 | ||
Encho Mishinev | Bulgaria | G 2017 | G 2014 | S 2016 | S 2015 | S 2013 | ||
Egor Lifar | Russia | G 2021 | G 2019 | S 2020 | S 2018 | S 2017 | ||
Harris Leung | Hong Kong | G 2021 | G(III) 2020 | S 2019 | B 2018 | B 2017 | ||
Zixiang Zhou | Canada | G 2022 | G 2021 | G 2020 | G(III) 2019 | S 2018 | ||
Wolfgang Thaller | Austria | G 1997 | G 1996 | S 1999 | S 1998 | |||
Andrzej Gąsienica-Samek | Poland | G 1999 | G 1998 | G 1997 | S 1996 | |||
Martin Pettai | Estonia | G 2002 | G 2001 | G 2000 | S 1999 | |||
Alex Schwendner | United States | G 2005 | G 2003 | S 2004 | S 2002 | |||
Filip Wolski | Poland | G(I) 2006 | G 2005 | G 2004 | G 2003 | |||
Goran Žužić | Croatia | G 2008 | G 2007 | S 2009 | B 2006 | |||
Vlad Alexandru Gavrilă | Romania | G 2013 | G 2012 | S 2011 | B 2010 | |||
Eduard Batmendijn | Slovakia | G 2015 | G 2013 | G 2012 | S 2014 | |||
Rareș Darius Buhai | Romania | G 2015 | G 2014 | G 2013 | G 2012 | |||
Yuta Takaya | Japan | G(I) 2017 | G 2016 | G 2015 | G 2014 | |||
Nikoloz Birkadze | Georgia | G 2020 | G 2019 | G 2018 | S 2017 | |||
Dorijan Lendvaj | Croatia | G 2022 | G 2021 | S 2020 | B 2019 | |||
Patrick Pavić | Croatia | G 2022 | G 2021 | G 2020 | S 2019 | |||
Fredrik Huss | Sweden | GP(I) 1993 | GP(I) 1992 | S 1991 | ||||
Martin Mareš | Czech Republic | G 1995 | G 1994 | GP(I) 1993 | ||||
Vladimir Martianov | Russia | G 1999 | GP(I) 1998 | G(I) 1997 | ||||
John Pardon | United States | G 2007 | G 2006 | G 2005 | ||||
Marcin Andrychowicz | Poland | G 2008 | G 2007 | G 2006 | ||||
Neal Wu | United States | G 2010 | G 2009 | G 2008 | ||||
Shogo Murai | Japan | G 2012 | G 2011 | G 2010 | ||||
Scott Wu | United States | GP(I) 2014 | G 2013 | G 2012 | ||||
Jarosław Kwiecień | Poland | G 2016 | G 2015 | G 2014 | ||||
Vladimir Romanov | Russia | G 2019 | G 2018 | G 2017 | ||||
Masataka Yoneda | Japan | G 2020 | G 2019 | GU 2018 | ||||
Daiki Kodama | Japan | G 2023 | G 2022 | G 2021 |
Feeder competitions
[edit]Most participating countries use feeder competitions to select their team. A number of these are listed below:
- The participants of which are chosen from the Canadian Computing Competition
- Central European Olympiad in Informatics
- Indian Computing Olympiad
- National Olympiad in Informatics
- National Olympiad in Informatics, China
- Ro:Olimpiada Națională de Informatică[69]
- NL:Nederlandse Informatica Olympiade[70]
- Es:Olimpiada Mexicana de Informática
- South African Computer Olympiad
- Syrian Olympiad in Informatics
- Turkish Informatics Olympiad
- United States of America Computing Olympiad
- Moroccan Olympiad in Informatics
- All Ireland Programming Olympiad
- Indonesian Olympiad in Informatics
- Egyptian Olympiad in Informatics
- National Olympiad in Informatics - Philippines[71]
- Bundeswettbewerb Informatik - Germany
- Vietnamese Olympiad in Informatics
Notes
[edit]- 1.^a IOI 2020 virtual closing ceremony was held on September 23, 2020.
See also
[edit]- List of computer science awards
- International Science Olympiad
- International Collegiate Programming Contest
- Central European Olympiad in Informatics
- Competitive programming
- International Mathematical Olympiad
References
[edit]- ^ a b Robson, Frank (10 August 2013). "Numbers game". The Sydney Morning Herald. Retrieved 17 August 2013.
- ^ "Competition Equipment". IOI 2024 Egypt. Arab Academy. Retrieved 29 July 2024.
- ^ a b "Minutes of the Meetings held in Kazan, Russian Federation" (PDF). ioinformatics.org. General Assembly of International Olympiad in Informatics. 19 August 2016. pp. 7, 11.
- ^ "IOI 2010 Waterloo". IOI 2010 Waterloo. University of Waterloo. Retrieved 29 July 2024.
- ^ Maggiolo, Stefano (2015). "An Update on the Female Presence at the IOI" (PDF). Olympiads in Informatics. 9, 127–137 (2015). London, U.K.: ioinformatics.org: 127–137. doi:10.15388/ioi.2015.10. Retrieved 13 July 2017.
- ^ "European Girls' Olympiad in Informatics". European Girls’ Olympiad in Informatics. European Girls’ Olympiad in Informatics.
- ^ "Zhezheng Luo". stats.ioinformatics.org.
- ^ Simões, Gabriel (31 July 2017). "IOI 2017, first round - Codeforces". Codeforces. Retrieved 4 August 2017.
There is really only one USA contestant on site, it looks like he came with the Chinese team (straight from China).
- ^ "IOI 2017: Results". stats.ioinformatics.org.
- ^ "General Assembly Minutes of the Meetings held in Almaty, Kazakhstan 26 July – 2 August, 2015" (PDF).
- ^ "Number of Participants". ioi2022.id.
- ^ "IOI 1989 Results".
- ^ "IOI 1990 Results".
- ^ "IOI 1991 Results".
- ^ "IOI 1992 Results".
- ^ "IOI 1993 Results".
- ^ "IOI 1993 Website". ioi1993.
- ^ "IOI 1994 Results".
- ^ "IOI 1994 Website". ioi1994.
- ^ "IOI 1995 Results".
- ^ "IOI 1996 Results".
- ^ "IOI 1997 Results".
- ^ "IOI 1998 Results".
- ^ "IOI 1999 Results".
- ^ "IOI 2000 Results".
- ^ "IOI 2001 Results".
- ^ "IOI 2002 Results".
- ^ "IOI 2003 Results".
- ^ "IOI 2004 Results".
- ^ "IOI 2005 Results".
- ^ "IOI 2005 Website". ioi2005.
- ^ "IOI 2006 Results".
- ^ "IOI 2007 Results".
- ^ "IOI 2007 Website". ioi2007.
- ^ "IOI 2008 Results".
- ^ "IOI 2009 Results".
- ^ "IOI 2009 Website". ioi2009.org.
- ^ "IOI 2010 Results".
- ^ "IOI 2010 Website". ioi2010.org.
- ^ "IOI 2011 Results".
- ^ "IOI 2011 Website". ioi2011.
- ^ "IOI 2012 Results".
- ^ "IOI 2012 Website". ioi2012.org.
- ^ "IOI 2013 Results".
- ^ "IOI 2013 Website". ioi2013.org.
- ^ "IOI 2014 Results".
- ^ "IOI 2014 Website". ioi2014.org.
- ^ "IOI 2015 Results".
- ^ "IOI 2015 Website". ioi2017.kz.
- ^ "IOI 2016 Results".
- ^ "IOI 2016 Website". ioi2016.ru.
- ^ "IOI 2017 Results".
- ^ "IOI 2017 Website". ioi2017.org.
- ^ "IOI 2018 Results".
- ^ "IOI 2018 Website". ioi2018.jp.
- ^ "IOI 2019 Results".
- ^ "IOI 2019 Website". ioi2019.az.
- ^ "IOI 2020 Results".
- ^ "IOI 2020 Website". ioi2020.sg.
- ^ "IOI 2021 Results".
- ^ "IOI 2021 Website". ioi2021.sg.
- ^ "IOI 2022 Results".
- ^ "IOI 2022 Website". ioi2022.id.
- ^ "IOI 2023 Results".
- ^ "IOI 2023 Website". ioi2023.hu.
- ^ "IOI 2024 Website". ioi2024.eg.
- ^ "IOI 2025 Website". ioi2025.bo.
- ^ "Hall of Fame". stats.ioinformatics.org.
- ^ http://olimpiada.info/Romanian National Informatics Olympiad Archived 2019-06-24 at the Wayback Machine
- ^ "Informatica Olympiade".
- ^ "Home — NOI.PH".
External links
[edit]![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)