We will hold AtCoder Grand Contest 077. This contest counts for GP30 scores.

Starting with this AGC, submitting a recording will be required in order to earn a GP30 score. Click here for details.

• Contest URL: https://atcoder.jp/contests/agc077
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20260329T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 6
• Writer: nok0, toam
• Tester: HIR180
• Rated range: 2000 -

The point values will be 800-900-1000-1000-1000-1800.

We are looking forward to your participation!

UPD: GP30 Ranking was updated (link).

AtCoder World Tour Finals 2026 will be held on the following dates. Details of the contests will be announced at a later date.

• Heuristic Contest: July 7 and 8
• Algorithm Contest: July 9

Original Post on AtCoder

Starting with AGC077 on 3/29, submitting a recording will be required in order to earn a GP30 score. For basic information about GP30 scores and AWTF2027, please refer to this article.

The detailed rules regarding recordings are as follows.

Recording Requirements

• Participants must record their entire screen during the contest. However, it is acceptable for part of the screen to be covered by a camera feed, as shown in the example below. Even in that case, be careful not to obscure important areas such as coding or program output.
• If multiple monitors are used, all of them must be recorded.
  • However, if a tablet is used for notes or scratch work, recording it is not required.
• No specific screen resolution is required, but the text must be legible.
• The frame rate must be at least 10 FPS.
• In addition to the screen recording, you must also record yourself during participation.
  • The format does not matter, such as recording your face with a webcam or your full body with a smartphone, but it must be possible to verify that you yourself are participating.
• Audio is not required for either recording.
• The screen recording and the recording of yourself may be submitted separately, but combining them into a single video is recommended.
• As an example of a valid recording, please refer to this video.

Operation

• If you do not wish to receive GP30 points, you do not need to submit a recording. Your rating will still change even if you do not submit a recording.
• Participants who wish to receive GP30 points must, if they place within 50th in a GP30-eligible contest, upload their recording data to an online storage service or video-sharing service and submit the URL. Specifically, register for this dummy contest and submit the URL there to the only problem using Text (cat). You may include additional information besides the URL, but do not write anything irrelevant.
• The recording data does not need to be publicly available. For example, an unlisted YouTube video satisfies the requirement.
• Participants who place in the top 50 will be notified by email. In addition, if rankings change due to bans or similar actions, participants who newly move into the top 50 will also be notified by email. Please note that these emails cannot be received unless “Receive important emails” is enabled in your user settings.
• Recordings must be submitted within 24 hours after the notification email is sent. Note that recordings may be submitted at any time regardless of rank, so if there is any possibility of earning points, we recommend submitting immediately after the contest ends.
• Among the participants within the top 50 who submitted a valid recording, GP30 points will be awarded to the top 30. Even if fewer than 30 participants are eligible to receive points, there will be no roll-down.

FAQ

• Q: Is it acceptable if there are periods when I do not appear in the recording? In particular, may I go to the restroom during the contest?
  A: Yes, that is not a problem. However, if excessively unnatural absences stand out, the points may be invalidated.

• Q: Can I still receive points if part of the recording data is corrupted?
  A: Depending on the extent of the corruption, points may still be awarded even if the recording is not completely intact. If you are unsure, please submit the recording. Including an explanation of the situation may work in your favor.

We will hold AtCoder Grand Contest 076. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc076
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20251228T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: maroonrk
• Tester: maspy, HIR180
• Rated range: 2000 -

The point values will be 700-1100-1200-1400-1400.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 075. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc075
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20251221T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: PCTprobability
• Tester: maspy, HIR180
• Rated range: 2000 -

The point values will be 600-800-1200-1200-1600.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 074. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc074
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20251026T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: hint908, vwxyz
• Tester: HIR180
• Rated range: 2000 ~

The point values will be 700-800-900-1100-1200.

Note that generative AIs are no longer allowed in AGC. Please refer to this post for the rules.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 073. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc073
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20250928T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 4
• Writer: maroonrk
• Tester: maspy, HIR180
• Rated range: 2000 -

The point values will be 700-1000-1400-1700.

We are looking forward to your participation!

UPD and announcement about the AI usage in this contest

First of all, I'm terribly sorry for what happened today; Problem C was solved by an AI. It is legal to use AI in AGC contests. However, this rule was adopted under the assumption that we would not provide problems that are solvable solely by AI. What makes the situation worse is that, as far as I know, only paid plans are able to solve this problem. This is especially serious, and I fully accept your frustration.

Of course, I tested this problem (and other problems) with GPT5-Pro until I reached the query limit, and it didn't succeed. I should also note that the initial version of C was asking for a slightly different thing, and I tested the current statement only twice, but I don't think that's the root cause of this incident.

I should have paid more attention to the development of AI. I knew that some hard CF/IOI/ICPC/PE/etc. problems were solved by AI. Many people asked me about whether (or when) to ban AI in AGC. I had several chances to reconsider the rules. However, I was overconfident and thought, "Hmm, there do exist good problems that aren't solvable by AI, so I can just choose them." As you know, I didn't have the ability to identify such problems.

As I said, the current rules of AGC don't restrict the use of AI, so making the contest unrated would feel like applying an ex post facto law. Therefore, my current plan is as follows:

• Keep this contest rated (and count GP30 scores).
• Ban AI for future AGC contests.
• Hold more AGCs to mitigate the effects of this incident.

To realize the third point, I have to reconsider the style of AGC. I'm not exactly sure about what changes to make, but one possible idea is to make a contest that is somewhere between ARC Div.1 and the current AGC.

Again, this is entirely my mistake and I sincerely apologize to all participants. I would also like to express my deepest gratitude to everyone who participated in this contest under such circumstances.

AGC admin, maroonrk

original post on AtCoder

We will hold AtCoder World Tour Finals 2025 Algorithm.

• Contest URL: https://atcoder.jp/contests/awtf2025algo
• Mirror Contest URL: https://atcoder.jp/contests/awtf2025algo-open
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20250717T1200&p1=248
• Duration: 300 minutes
• Number of Tasks: 5
• Writer: maroonrk
• Tester: maspy, HIR180, hirayuu_cf
• Rated range: Unrated

The point values will be 800-1000-1400-1400-2000. We don't freeze the standings in the contest.

AtCoder World Tour Finals 2025 is an international onsite contest. We have invited top-runners of AtCoder Race Ranking 2024 to Tokyo. On the contest day, we will stream the contest on our YouTube channel. For more details, please visit this page.

The mirror contest is Unrated and the standings is hidden. Other rules are the same as AGC. Specifically, there are no restrictions on the usage of AI.

We will hold AtCoder Grand Contest 072. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc072
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20250420T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: E869120, square1001
• Tester: HIR180
• Rated range: 2000 -

The point values will be 900-1100-1100-1400-1400.

We are looking forward to your participation!

This is a story about my recent contest participation.

Let's call the contest X. X was an international contest with online qualification rounds and the onsite Finals, with trip and hotel expenses covered by the organizer. In other words, X was a very important contest for me.

Hoping to go to the Finals, I participated in the qualification round. However, when I opened the last problem, I immediately remembered that the exact same problem had previously been submitted to AtCoder. I also knew that the submitter of that problem was among the organizers of X.

Let's call the author of that problem Y. I immediately messaged Y about this issue. At first, I thought that Y had simply forgotten that he had submitted the problem to me, but the situation was a bit more complicated.

Y did remember he had submitted the problem to me but still used it in another contest. Why? Because I had given him permission!

To make things clear, let me show you the relevant chat log between me and Y.

I said X sounds OK. so it's totally my fault, case closed...? Let me defend myself.

When this conversation happened, X was just an online contest and therefore it wasn't an important one for me. Actually, an online version of X happened about a month after this chat. (To be more precise, there was an onsite contest for X but it's for locals and there were no invitations to foreign participants.)

Then, a few months later, it was announced that the next X would invite international contestants. At this point, I completely forgot that I had said X sounds OK.. Instead, I only remembered I'd appreciate it if you could avoid using the remaining problems in important contests., and I thought it was obvious that X was important to me.

As you know, Y didn't understand what I was thinking, and that's how the incident happened.

I should have said "don't use the problem for international onsite contests or its qualifications" in the first place. When chatting, I thought only UCUP could cause a "collision" so I only mentioned UCUP. This is my fault.

Y should also have told me that he's going to use the problem when the contest was announced (or the problem was accepted). He was mentioning X in the chat but the problem was used in the next-next X, which was confusing to me.

I do feel frustrated about this incident, but I also think it's partly due to my fault. That's why I accepted the request from the author not to include the contest name or the author's name. I know you can infer what exactly X and Y are, but please don't comment on them.

After all, what's this blog for? It's a rant to appease myself. It's an excuse for not advancing to the Finals. And last but not least, I want to raise awareness about what to be careful about when submitting your problems to other contests. Specifically, if your problem is used in a contest, everyone who knows the problem should be informed in advance when and where it will appear, and you should let them know as early as possible.

Or more generally, it’s better to over-communicate than to under-communicate!

We will hold AtCoder Grand Contest 071. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc071
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20250330T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: chinerist
• Tester: maspy, HIR180
• Rated range: 2000 -

The point values will be 700-900-1100-1300-1700.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 070. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc070
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20241229T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: Nyaan
• Tester: maspy, HIR180
• Rated range: 2000 -

The point values will be 600-1000-1000-1800-1800.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 069. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc069
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20241124T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: m_99
• Tester: maspy, HIR180
• Rated range: 2000 -

The point values will be 900-1000-1200-1200-1200.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 068. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc068
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240929T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: maroonrk
• Tester: maspy, HIR180
• Rated range: 2000 -

The point values will be 900-900-1200-1200-1200.

We are looking forward to your participation!

We will hold Marubeni Programming Contest 2024 (AtCoder Regular Contest 183).

• Contest URL: https://atcoder.jp/contests/arc183
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240825T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, sigma425
• Rated range: — 2799

The point values will be 400-600-600-800-900-1100.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 067. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc067
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240818T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 5
• Writer: Kubic, JohnVictor
• Tester: HIR180, zhoukangyang
• Rated range: 2000 -

The point values will be 600-1100-1100-1500-1900.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 182.

• Contest URL: https://atcoder.jp/contests/arc182
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240811T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: sounansya, hirayuu_cf
• Tester: maspy
• Rated range: — 2799

The point values will be 500-500-600-700-800-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 181.

• Contest URL: https://atcoder.jp/contests/arc181
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240804T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: chinerist
• Tester: maspy, sigma425
• Rated range: — 2799

The point values will be 300-600-600-700-1000-1100.

We are looking forward to your participation!

We will hold AtCoder World Tour Finals 2024.

List of Finalists:

• Contest URL: https://atcoder.jp/contests/awtf2024
• Mirror Contest URL: https://atcoder.jp/contests/awtf2024-open
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240712T1230&p1=248
• Duration: 300 minutes
• Number of Tasks: 5
• Writer: maroonrk
• Tester: hos.lyric, yosupo, maspy, nuip, HIR180, sigma425, nok0
• Rated range: Unrated

The point values will be 700-1000-1500-2000-2000. We don't freeze the standings in the contest.

AtCoder World Tour Finals 2024 is an international onsite contest. We have invited top-runners of AtCoder Race Ranking 2023 to Tokyo. Since cnnfls_csy (8-th in the race) couldn't come to the Finals, ugly2333 has advanced as the runner-up. For more details, please visit this page (https://info.atcoder.jp/more/contents/awtf/2024) (this is under construction, though).

Note that, unlike last year, the mirror contest is Unrated and the standings is hidden.

About Streams

On the contest day, we will stream the contest on our YouTube channel. This year we have a special guest Petr! I and he will be watching the contest and discuss problems. Obviously, Finalists should not watch the stream during the contest. The mirror contest participants can watch it since there's no way to prevent it. This is why the mirror is Unrated and the standings is hidden.

And last but not least, we had set up a "confessional booth" this year. This idea comes from the chess tournaments (example) — a room where you can go during the contest (one at a time, obviously) and say something to be shown on stream. This is a new attempt and we hope it makes the stream more interesting!

We are looking forward to your participation (in the mirror or stream)!

We will hold AtCoder Regular Contest 180.

• Contest URL: https://atcoder.jp/contests/arc180
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240629T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, yuto1115
• Rated range: — 2799

The point values will be 400-600-600-700-800-1100.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 179.

• Contest URL: https://atcoder.jp/contests/arc179
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240602T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: noya2
• Tester: maspy, potato167
• Rated range: — 2799

The point values will be 300-500-500-700-800-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 178.

• Contest URL: https://atcoder.jp/contests/arc178
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240519T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: potato167
• Tester: maspy, Nyaan
• Rated range: — 2799

The point values will be 400-600-600-700-1000-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 177.

• Contest URL: https://atcoder.jp/contests/arc177
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240512T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: E869120, square1001
• Tester: maspy
• Rated range: — 2799

The point values will be 300-400-500-700-1000-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 176.

• Contest URL: https://atcoder.jp/contests/arc176
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240421T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: PCTprobability
• Tester: maspy, Nyaan
• Rated range: — 2799

The point values will be 400-400-700-700-800-1000.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 066. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc066
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20240331T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 6
• Writer: maspy
• Tester: potato167, Nyaan
• Rated range: 1200 -

The point values will be 600-600-800-1100-1500-1600.

We are looking forward to your participation!