jonathanirvings's blog

By jonathanirvings, history, 31 hour(s) ago, In English

Hi,

We would like to invite you to participate in the live online mirror contest of The 2024 ICPC Asia Pacific Championship next weekend. ICPC Asia Pacific Championship is a new playoff round introduced to the Asia Pacific region this year. It is the contest for top non-winning teams from all regional contests in the region to qualify to the World Finals. See the region rules and competition page for more details.

The official contest is scheduled to start at Saturday, 2 March 2024, 9am (UTC+7). The live online mirror contest is scheduled to start only 5 minutes later, to keep both contests run almost in sync. The contest is 5 hours long and consists of several problems.

Please note that we might have to postpone the live online mirror contest in case the official contest is delayed. This is to the ensure that the tasks are not available to the public until the official contest starts.

The contest will use ICPC-style scoring (same as the official contest) and will be unrated. You can participate as an individual or as a team, although as a team of three members is preferred.

See you on top of the leaderboard.

The 2024 ICPC Asia Pacific Championship Judges

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By jonathanirvings, history, 5 months ago, In English

TL;DR: As I mentioned in a recent comment, IMHO regular contests should be (at most) 2 hours long and keep longer contests for special/tournament events.

Personally, one of the main reason for me to compete in less contests in the recent years is that unfortunately I have less time to do programming contests. This becomes worse since Codeforces now have more and more contests longer than 2 hours. It's very hard for me to find more than 2 continuous hours for programming contest. I believe this situation might not be unique to me.

Below are the currently scheduled Div. 1 rounds.

Name Duration
Codeforces Round (Div. 1) 03:00
Codeforces Round (Div. 1) 02:30

Below are the last 10 Div. 1 (or "combined") rounds. Only one of them was 2 hours long.

Date Name Duration # of problems
09/18 CodeTON Round 6 (Div. 1 + Div. 2, Rated, Prizes!) 02:15 (was modified from 02:00 less than 24 hours before the contest) 8
09/10 Codeforces Round 896 (Div. 1) 02:30 6
08/30 Pinely Round 2 (Div. 1 + Div. 2) 03:00 9
08/26 Harbour.Space Scholarship Contest 2023-2024 (Div. 1 + Div. 2) 03:00 9
07/29 Codeforces Round 889 (Div. 1) 02:30 6
07/23 Codeforces Round 887 (Div. 1) 02:30 6
07/11 Codeforces Round 884 (Div. 1 + Div. 2) 03:00 8
06/24 CodeTON Round 5 (Div. 1 + Div. 2, Rated, Prizes!) 03:00 9
06/18 Codeforces Round 880 (Div. 1) 02:00 6
05/28 Codeforces Round 875 (Div. 1) 02:30 6

Below are the distributions of Div. 1 (or "combined") contests since the start of Codeforces. The left-end is the start of Codeforces (2010), while the right-end is today. Blue line is "2h contest", while red line is "more than 2h contest". It is clear the trend is going for "more than 2h" contest. Better resolution image here.

Please bring back the old Codeforces with more 2-hour contests. I can't promise anything, but if future task authors would like to create a 2h contest, it will be much more likely that you will have one additional participant. :) If you are worried that 2 hours is too short for participants to solve your 6 problems, then save one problem for future rounds. You can then create more rounds. Win-win solution. :) Keep longer rounds for special/tournament events, like Meta Hacker Cup.

Call me boomer or whatever you want. I don't care.

PS: In case you are wondering, it took less than 2 hours for me to write this blog (including creating the chart).

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By jonathanirvings, history, 7 months ago, In English

There is a fine line between the bottom 50 percentile and the top 50 percentile.

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By jonathanirvings, history, 7 months ago, In English

The ICPC Asia Pacific rules for the 2023-2024 cycle has just been announced in https://icpc.iisf.or.jp/asia-pacific/top/2023-24-cycle/. New to this cycle is the Playoff Contest, which is the contest for top non-winning teams from all regional contests in the region to qualify to the World Finals.

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By jonathanirvings, history, 12 months ago, In English

In the Topcoder Community Town Hall today, it was announced that (if I heard and understood correctly) Topcoder Open (TCO) 2023 will be the last TCO and it will be a virtual event.

WIth the recent Google Coding Competitions shutdown announcement, it is an end of an era indeed :'(

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By jonathanirvings, history, 18 months ago, In English

IOI 2022 Task Discussion (Editorial) is now available here. The link has been posted in the IOI 2022 Tasks page as well.

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By jonathanirvings, 20 months ago, In English

Disclaimer: all opinions written in this post are purely personal and not tied with any affiliation, organization, or institutional I am working with, including but not limited to the IOI 2022 organizers. Several members within IOI 2022 organizers might even try to prevent me from posting this.

Dear IOI Community in Codeforces,

I am writing in Codeforces this time, not in e-mails or IOI 2022 website since I am writing this in personal capacity and should not reflect a formal opinion of the IOI 2022 organizers. As you all might know, IOI 2022 will be conducted hybrid -- it will be hosted onsite, but we understand that it is impossible for some countries to come to Indonesia due to the current global pandemic, so these countries are still allowed to officially participate online. I am going to be very honest and transparent in this post.

This is the first time the IOI has a hybrid setting like this. This poses huge challenge for the organizers. We need to practically support 2 IOIs: those who come onsite (their visas, accomodations, transports, competition venues and equipments, etc.) and those who participates online (their VMs, technical supports, communication platforms, competition server in cloud, etc.). As a reminder, the Singapore organizer explicitly ruled out the hybrid option very early in 2021 due to the challenges and their manpower limitation. They wanted to host either fully onsite or fully online IOI 2021.

Also, our technical committee became a member of the International Technical Committee only for the past 2 years, and our International Committee representative became a member of the International Committee only for the past 3 years (this is in line with IOI Regulation S3.14). This means that we only observe the preparation of IOI only since 2019. Only 1 IOI has been conducted onsite since then. For the technical committee, they only observe it since 2020, which are conducted fully online. We are working very hard on catching up what we need to do to conduct an onsite IOI, and also working very hard on doing them.

We also just realized earlier this year that while quarantine restriction has been lifted up for vaccinated travellers entering Indonesia, the visa policy is not trivial. In April, we met with 15 international committtee members in Yogyakarta. Due to the pandemic, all of them (even our neighbouring Singaporeans) require a visa. They can't apply themselves -- it needs to be sponsored by an entity in Indonesia. Thus, we needed to process their visas on our side. The visa situation is slightly better now, that most nationalities do not need visa or can apply a visa on arrival. However, that still leaves up to 20+ teams that we need to process their visas.

If all these are not enough, IOI 2022 will also be the first IOI with delegations competing under the IOI flag. There are two such delegations, therefore the IOI team will contain 8 official participants. To make sure we can accomodate this, we need to extend and test all of existing IOI systems that usually assume each team has only up to official 4 contestants.

In all, I would like to point out and emphasize the challenges that we have to start bringing back IOI participation to onsite. However, I still believe that it is good to bring back the face-to-face interaction within the IOI community, which we don't have over the past 2 years. Therefore, we decided to host IOI 2022, despite the massive challenges we have.

I would like to mention several requests that we have received in our email. Again, keep in mind that everything posted here are PERSONAL OPINIONS AND NOT TIED with IOI 2022 organizers. Most of them are valid and understandable requests, but I feel like some of them are very stretched and burdened us with additional challenges on top of the list of massive challenges that we already have.

1) Some countries concerned that their students are not vaccinated, thus they will be quarantined in Indonesia based on the current policy. Please remember that earlier in January this year, the IOI President has sent everybody an email reminding all delegations to be vaccinated. In April, we publicized all of the IOI President's email in our website. While we try hard on our end to negotiate with our authorities, please stop asking whether non-vaccinated minors can enter Indonesia. Many regulators, including FDA, have approved several vaccinations for minors. Please vaccinate your students if they want to compete in Indonesia, or take your own risk that they might be quarantined. Use the recent controversy of a tennis player as a lesson. We hope to be able to see all of you here, but quarantine policy is not under our control.

2) This one is what grinds my gear and makes me write this post. A delegation appealed to bring an extra unofficial contestant (on top of the four official contestants) to participate in Indonesia, quoting IOI Regulation S2.8. When we rejected the request, quoting E2.8 that such request must be agreed with the host, the delegation escalated the request to the IOI President. (as a matter of fact, we already consulted with the IOI President regarding this request, and E2.8 was actually pointed out by the President). After that, they sent two more e-mails to us asking about our decision again. Really?

3) Some countries mentioned to us that flights to Indonesia are expensive. Indeed, after recent quarantine relaxations across several countries in South East Asia, ticket fares around here are incredibly expensive, presumably due to high demand. I, myself, cancelled some personal plans (unrelated to IOI 2022) to travel to Indonesia due to this reason. What I can say here is that plan and book your travel as early as possible to avoid an even higher surge of price.

In conclusion, I want to remind that despite the massive list of challenges that we are going to face, we decided to invite teams to attend IOI 2022 onsite. We want to make the best programming contest experience for all of the contestants and the delegation leaders. I know how important IOI is for high school students for the rest of their life. Believe me, I was an IOI participant myself. If we can, we want to accept all these incoming requests, but unfortunately I feel like some of them are too stretched. Focusing and handling all these requests might actually distract us on doing the important things. If you have some requests, please think back and consider if all 80+ teams make the same requests, and put yourself in our shoes. Are the requests reasonable? If you are the committee, will there be something you can do, and will you be stressed handling those kind of requests?

I said this before in my Facebook post and I am going to blatantly brag again: If we somehow pull this of, I will claim that Indonesia is the best IOI Organizer ever in the history of IOI.

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By jonathanirvings, history, 2 years ago, In English
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By jonathanirvings, history, 3 years ago, In English

I have been thinking about this for more than a year. I think it's time to share my thoughts. Disclaimer: all opinions written in this post are purely personal and not tied with any affiliation/institution I am working with.

The global pandemic we are encountering has affected many aspects of our life. While we need to adapt to doing most of our activities online, competing in the International Collegiate Programming Contest (ICPC) -- or similar high-stakes team programming contest -- should not be one of them.

I have no objection to the following online contests: International Olympiad in Informatics (IOI), Google Code Jam (GCJ) final, Facebook Hacker Cup (FBHC) final, and any similar contest final which is participated by the best ~20 competitive programmers in the world. What makes them different from ICPC is the amount of trust we have put in the contestants or their local community.

In the case of IOI, IOI has been built by the strong community we have among the delegation team leaders. We have put so much trust in them by letting them read the tasks several hours before the contest, and take a vote in important decisions regarding the competition. This fact makes it easy to just let the team leaders (or someone trusted by the team leaders) physically proctor the contestants.

In the case of GCJ, FBHC, etc. finals, the competition is participated only by the best ~20 competitive programmers in the world, usually almost all of them are Codeforces LGM. The usage of any materials written before the contest (including the internet) is usually allowed. The only prohibited action is to communicate with other people. However, these competitors are well-known and respected members of the community. At their level, they do not gain a huge (if any) advantage by communicating with most other people. Also, they are risking their huge reputation by trying to communicate with other people. It's just not worth it.

It is entirely different in ICPC. Even in the World Finals, it is competed by 100+ teams. Different from GCJ finals, they are not the best teams in the world due to the process of qualifying to the World Finals with the regionals. Without intending to disrespect these teams, usually, not many people know the teams on the bottom half of the scoreboard. Given how prestigious ICPC is, I can imagine how some teams might do what they are not supposed to do for glory. Additionally, ICPC setup is unique in having one workstation/team and the importance of hardcopy printings, which makes it more complicated to do it online.

It is not better in the regionals. The regionals are still an important and prestigious contest since it determines the teams going to the World Finals. However, it is competed by even less known teams. Some of these teams even compete with lower effort and without the support of their university, which makes it harder to enforce them to a slightly complicated online setup. It is just hard (if not impossible) to ensure that they are not using any prohibited materials. In IOI, most contestants are supported by many people (at the very least, their team leader. most are supported by their government and local community as well), which makes it easier to enforce a sophisticated VM/VPN setup to monitor the contestants' activity in their workstation as well.

Generally, I just think that online proctoring (in whatever format) just does not make much sense. Regardless of how many cameras or screen recordings are enforced, once the contestants leave the camera coverage, no one knows what happened (the contestants may talk to other people, access the internet, etc.). All competitors must be physically proctored by someone we can trust.

That is why I believe that ICPC World Finals 2020 should be postponed until it is possible to host it on-site and participated by (almost) all finalists. ICPC Regionals 2020 should not have happened -- ICPC Regionals 2020 and ICPC World Finals 2021 should have been suspended. When the ICPC is resumed, all contestants who are supposed to be eligible for ICPC Regionals 2020 can participate.

Some of you might know that I am the chief judge of the last four years of the Jakarta site. I am not happy with the decision that Jakarta was hosting ICPC Regional 2020 online and will be hosting ICPC Regional 2021 (most likely online). Jakarta was the only online site in the Asia-Pacific region last year and many teams in this region can only compete on this site. Nevertheless, I still just prefer that ICPC Regional did not happen last year. There were some issues from last year that was caused by online proctoring, such as different teams were mistakenly enforced different rules by different proctors (despite the huge effort of briefing the proctors, it still happened) and teams were getting disqualified because they were not able to gather their team members.

I will not be the chief judge of the Jakarta site this year.

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By jonathanirvings, history, 3 years ago, In English

Dear Codeforces community,

The Call for Tasks for the International Olympiad in Informatics (IOI) 2022 is now open. IOI is the most prestigious programming contest for pre-university students. The Host Scientific Committee of IOI 2022 invites everyone (other than potential IOI 2022 contestants) to submit their task to the IOI 2022 Call for Tasks. We welcome any tasks of various difficulty levels.

Each submitted task should contain at least the following:

  • author(s) information: name, e-mail, affiliation, country, and author's role in national olympiad;
  • task statement (PDF is preferred);
  • description of the desired solution.

The authors of the shortlisted (around 10) tasks will be invited to attend the IOI 2022 in Indonesia. In the case the task authors reject the invitation, or are ineligible to be invited (due to the current pandemic), they will be awarded IOI 2022 souvenirs (including, but not limited to T-shirts) by mail. Additionally, the authors of tasks included in the actual competition will also be recognised by listing their name, affiliation, and country on the official IOI website (unless they specifically decline this).

For more details (including how and where to submit the task), please check the IOI 2022 Call for Tasks page. For any questions, please reach out to [email protected]. We hope to see great tasks from the community.

Thank you,

IOI 2022 Host Scientific Committee

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By jonathanirvings, history, 3 years ago, In English

Hi all,

As a preparation for the Indonesian Informatics Olympiad committee to host IOI 2022, we decided to organise a test contest using CMS, the contest system used for IOI since 2012. The main purpose of this contest is for us to be familiar with CMS, including troubleshooting issues that may arise before, during, or after the contest.

Therefore, we would like to invite everyone to participate in this contest. The contest will be held on Sunday, 10 January 2021 9:05PM UTC+7 (Western Indonesian Time).

Since we are using the contest to be familiar with IOI-related features in CMS, the contest follows several IOI specifications, including:

  • There are batch, output-only, interactive, and communication tasks.
  • For non output-only tasks, you only need to implement one or more functions specified in the problem specification.
  • There are one or more subtasks for each task.
  • Full-feedback for each submission will be given (there is no pretest).
  • The supported programming language is C++ (IOI will no longer support Java from 2021).

However, the quality, novelty, and difficulty of the tasks may not be the same as IOI. Since this is a test contest, we are trying to make the contest as fun and approachable as possible. The contest duration is 2 hours.

The contest will be hosted in https://cms.toki.id/. To participate in the contest, you will need to register in this form by the end of Friday, 8 January 2021 UTC+7 (Western Indonesian Time).

We are planning to distribute TOKI souvenirs to random participants with a non-zero score of this contest. The details of the souvenirs are yet to be confirmed. We will update the post once the details are confirmed.

See you in the contest :)

UPD1: The problems are now available for upsolving in TLX. Note that we need to modify several details due to CMS vs TLX incompatibilities.

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By jonathanirvings, history, 4 years ago, In English

Hi all,

We invite everyone to participate in APIO 2020 Open Contest. The open contest will have the same problemset as APIO 2020, but every TLX user can participate in the contest.

The contest runs for 5 hours and will be held virtually, which means you can participate the contest at anytime between Tuesday, 18 August 2020 (08:00 UTC+7) and Thursday, 20 August 2020 (08:00 UTC+7). When you start the contest, your individual 5-hour timer will start.

More details can be seen in https://apio2020.id/open.html. The contest can be accessed in https://tlx.toki.id/contests/apio-2020-open.

UPD: The open contest results is available here.

Thanks,
Scientific Committee, APIO 2020

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By jonathanirvings, history, 4 years ago, In English

Hi all,

Apologize in advance to add more discussion regarding COVID-19.

As decided in the APIO delegation meeting in the last year's IOI, Indonesia is supposed to organize Asia-Pacific Informatics Olympiad (APIO) 2020. We have planned to run it on 9-10 May 2020, as we have announced it on our website.

However, we realize that the situation of the world regarding COVID-19 has changed rapidly in just a matter of days. Therefore, APIO 2020 organizer is currently considering our options regarding hosting APIO 2020. Given that IOI 2020 is postponed and will not take place any earlier than September 2020, we realize that APIO delegations might adjust their team selection timeline, thus affecting their participation in APIO if it is still hosted in May. We also realize that several national informatics olympiads have been canceled which might affect their participation in APIO as well.

If we still have to host APIO 2020 in May, we understand that the long-standing APIO regulation which enforces contestants to be supervised/invigilated in a contest site is not feasible. This is due to lockdown and quarantine policies in several countries, as well as discouraging gathering of several people in the same place. In other words, we will have to conduct a full online APIO where contestants can solve the problems from their place and trust them to follow the rules of APIO 2020.

We would like to hear any thoughts from the competitive programming community, regardless of whether you are an IOI/APIO contestant or coach, and also regardless of whether you are representing an APIO delegation country or not. Should APIO 2020 be postponed as well? Is it okay to run a full online APIO? However, as you might imagine, please understand that this is an unofficial discussion just to get a rough idea of what people are thinking. We might conduct an official survey that is directed to only APIO delegation leaders at a later date.

Jonathan, on behalf of APIO 2020 Organizer.

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By jonathanirvings, history, 4 years ago, In English

Hi,

We would like to invite you to participate in the live (with 30-minute delay) online mirror contest of The 2019 ICPC Asia Jakarta Regional Contest (our regional website, our regional in ICPC website, official contest portal) this weekend. The online mirror contest will start on Oct/27/2019 06:30 (Moscow time).

The contest consists of several problems and you can solve them in 5 hours.

See you on top of the leaderboard.

UPD1: Thanks for participating. The problems should be available for upsolving. The soft-copy of the problem analysis (the same as the one distributed to all contestants during the awarding ceremony) is available here.

UPD2: The full problem repository is available here. The full problem repository for Indonesia National Contest (INC) 2019, which is the national programming contest that serves as the online preliminary round for Indonesian teams to advance to The 2019 ICPC Asia Jakarta Regional Contest, is also available here. The problems are also available for upsolving in TLX (INC and ICPC)

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By jonathanirvings, history, 5 years ago, In English

Hello!

Similar to last year, we are excited to invite you to TOKI OSN Open Contest 2019 -- an online mirror contest for Indonesia national olympiad in informatics. This national olympiad is one of the stages required for our students to qualify to represent Indonesia in the International Olympiad in Informatics (IOI).

The contest is similar to IOI: 2 competition days (+ 1 trial session), each consisting of 3 IOI-style (partial, subtasked) problems to be solved in 5 hours. The schedule is as follows:

Each contestant can select any 5-hour window within the time range to do the contest for each competition day. Each contestant may start the contest any time within the time range, by clicking a provided timer button.

All three contests are now available on TLX. Please register in those contests. You may need to register for a TLX account if you do not have one.

For more detailed information and rules, see our official website.

See you in the leaderboard! :)

UPD1: The contest is over, thanks for participating. We are still working on the post-contest blog summarizing the contest, including the problem repository and credits. Meanwhile, the scoreboard for TOKI OSN Open Contest 2019 is available here. The problems are also available for upsolving here (TLX account is required).

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By jonathanirvings, history, 5 years ago, In English

Google Code Jam to I/O for Women starts in 3 hours!

Code Jam to I/O for Women is a 2.5 hour single-online round coding competition. The top 150 on the scoreboard will receive a ticket and reimbursement to offset travel expenses to Google I/O.

Register now!

https://codingcompetitions.withgoogle.com/codejamio

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By jonathanirvings, history, 5 years ago, In English

jonathanirvings, Luqman, and wiwitrifai will stream ourselves doing the live mirror of 2018 ICPC Asia Singapore Regional Contest.

More detail on this post

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By jonathanirvings, history, 5 years ago, In English

UPD: 2018 ICPC Asia Jakarta Regional Contest problemset is now available on CODEFORCES Gym

UPD2: The original checker for problem C turns out to have non-deterministic behaviour due to insufficient array size. Fortunately, the false checking caused by the bug occurs rarely enough that the live contest (including the mirror in Codeforces) was not impacted (at least we did not receive complaints on the live contest). The checker was fixed on 23 June 2020 and all submissions have been rejudged. See this comment for more detail.

We would like to invite you to the mirror post-contest of 2018 ICPC Asia Jakarta Regional Contest. The contest will start on Sunday, 25 November 2018, 10.00AM Western Indonesian Time (UTC+7) (exactly 2 weeks after the real contest started).

The contest consists of 12 problems and you can solve them in 5 hours.

If you participated the contest, or have read the problems before, you are encouraged to not participate on the mirror post-contest :'( The problems should be available for upsolving after the 5 hours timer is up, though.

See you on top of the leaderboard (to those who plan to participate).

==== This post was heavily edited on November 20. The old post was kept below for archiving purposes. The title of the post was "2018 ICPC Asia Jakarta Regional Contest problemset on Gym" back then. ====

Sorry, I can't resist. (make sure to also read the "On a serious note" below the image)

On a serious note, following the comments on this thread, I am currently working on putting the problemset on (Codeforces) Gym, hopefully it can be done within a week or so. For those teams who are willing to participate in this contest virtually, my advice is not to read the problemset until then :) Stay tuned!

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By jonathanirvings, history, 5 years ago, In English

Throughout the year, Google Code Jam hosts online Kickstart rounds to give participants the opportunity to develop their coding skills, get acquainted with Code Jam’s competition arena, and get a glimpse into the programming skills needed for a technical career at Google.

Each Kickstart round gives participants 3 hours to solve challenging, algorithmic problems developed by Google engineers. Participating is a fun way to grow your coding skills—and potentially explore opportunities at Google.

Inviting you to solve some fun and interesting problems on Sunday, Oct 21, 2018 13:00 UTC (24 hours from now).

Dashboard can be accessed here during the contest. Problem analysis will be published soon after the contest.

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By jonathanirvings, history, 6 years ago, In English

Hello!

TOKI Open 2018 has ended. Thank you to everyone who participated the contest.

We decided to not consider any participants from the second window whose username is registered on the first window. We also decide to not consider any participants from the second window whose code is very similar to other user's code on the first window. After that, we consider a TOKI Open 2018 participant to be those who made at least one submission on either day.

There were a total of 104 participants, which three of them get a fullscore. Congratulation to 1021839, Alex_2oo8, and zscoder. The full result of TOKI Open 2018 is available here.

The skeletons, solutions, problem descriptions, and testcase generators for TOKI Open 2018 are available here. The problems are available for upsolving here. Alternatively, the PDFs version of the problems are available here (English, Bahasa).

The problems discussion (a.k.a. editorial) for TOKI Open 2018 is currently being written and should be done within two weeks time. I will update this blog post once it is ready. Stay tuned! :)

We also have prepared a feedback form for TOKI Open 2018. You can access the feedback form here. Please do fill them to help us conduct TOKI Open better in the future. It shouldn't take more than 5 minutes of your time :)

We thank everyone who are involved in TOKI Open 2018:

We hope to conduct TOKI Open again next year, with broader audience. If you have any inquiries, please contact [email protected]. See you next year! :)

UPD1: The problem discussion (a.k.a. editorial) for TOKI Open 2018 is available here

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By jonathanirvings, history, 6 years ago, In English

Hello!

After we successfully organized TOKI Open 2014 and TOKI Open 2017, we are going to do the similar thing this year. We will open our current IOI Selection Contest to international participants. We call it TOKI Open 2018. TOKI stands for Tim Olimpiade Komputer Indonesia, or Indonesian Computing Olympiad Team in English.

Objectives of us opening this contest include, but not limited to:

  • Measure the performance of our IOI trainee compared to other countries' IOI trainee.
  • Foster friendship between Indonesia and other IOI participating countries.
  • Test Indonesia's scientific committee capability in setting IOI-level problems.
  • Test Indonesia's technical committee capability in hosting IOI-level contests.

The contest will have very similar format with IOI, as this contest will be used to select our Top 4 and train our Top 4 for IOI. We expect that the difficulty of the contest is almost the same as IOI. Therefore, this contest is suitable for those who are preparing for IOI. The problems will be available in both Bahasa Indonesia and English.

The rules of TOKI Open 2018 are

  • There will be 3 IOI-style problems for each competition day.
  • You can only submit at most 50 submissions for a problem.
  • You will get full feedback for each submission.
  • For each problem, there are several subtasks:
  • For each subtask, there are points assigned to it.
  • Each subtask contains several test cases.
  • You get the points from that subtask if the program passes all the test cases in that subtask.
  • The score of a submission is the sum of all the points that you get from completing subtasks.
  • The final score for a problem is the maximum of all the submission scores for that problem.
  • Unfortunately only C++11 is supported. We will use g++ (Ubuntu 4.8.2-19ubuntu1) 4.8.2 (flags: -std=c++11 -O2 -lm) compiler
  • You will only need to implement several functions described in problem statement (i.e. no I/O is needed)
  • You can submit clarification requests in either Bahasa Indonesia or English.

The contest will be conducted on TLX Online Judge. You may need to register for a TLX Account if you do not have one. If you have a TLX account, you can login and go to the contest link to register for the contest. There will be two competition days, each having three problems. Each competition day will have two open windows containing the same problemset, so you can participate in either one of the window depending your time preference.

Day 1: Saturday, 26 May 2018

Day 2: Monday, 28 May 2018

A practice contest to get familiarised with TLX and the problem format is available here. The problems of TOKI Open 2017 are available for upsolving in the problem archive portal.

IMPORTANT: You are not allowed to register on both windows for the same competition day, since they will have the same problemset. If you have registered on a wrong window, you can go to the contest link to unregister.

We invite everyone (especially eligible IOI participants) to participate in this contest. See you at the leaderboard.

UPD1: The day of the second competition day is finalized. It will be on 28 May 2018.

UPD2: The preliminary result of TOKI Open Day 1 is available here. For those who registered in both windows, we only consider the score for the first window (including even if you did not make any submission in the first window).

UPD3: The post-contest blog post (includes problems repository, full result, etc.) is available here

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By jonathanirvings, history, 6 years ago, In English

Will there be an online mirror for 2018 ACM-ICPC World Finals? Thanks

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By jonathanirvings, history, 6 years ago, In English

Google Code Jam 2018 Practice Round has just been opened. It will be open for 48 hours.

Go to https://codejam.withgoogle.com/2018/ to check out our new competition platform :)

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By jonathanirvings, history, 7 years ago, In English

Is anyone else experiencing arena problem right now, or is it just me? I can't log in to the arena.

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By jonathanirvings, history, 7 years ago, In English

I am attending IOI 2017 and live tweeting IOI 2017. :)

https://twitter.com/jonathanirvings

Once we got the confirmation that IOI 2017 has started, I will upload the problems somewhere :)

Stay tuned.

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