maroonrk's blog

By maroonrk, history, 4 days ago, In English

We will hold AtCoder Regular Contest 155.

The point values will be 400-500-700-800-900-1000.

We are looking forward to your participation!

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By maroonrk, history, 11 days ago, In English

We will hold AtCoder Regular Contest 154.

The point values will be 300-400-500-700-900-900.

We are looking forward to your participation!

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By maroonrk, history, 3 weeks ago, In English

We will hold AtCoder Regular Contest 153.

The point values will be 300-500-600-800-800-1000.

We are looking forward to your participation!

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By maroonrk, history, 4 weeks ago, In English

(Original post)

We've published the results of the GP30 race of the current and previous seasons.

We are planning to host an onsite WTF in 2023 with the top 8 contestants of each season. We'll announce more details of the Finals once we decide.

Above all, congrats to the all Finalists!

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By maroonrk, history, 6 weeks ago, In English

We will hold AtCoder Grand Contest 060. This contest counts for GP30 scores, and it's the last contest of this season.

The point values will be 400-700-800-1000-1400-2200.

We are looking forward to your participation!

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By maroonrk, history, 2 months ago, In English

We will hold AtCoder Regular Contest 152.

The point values will be 400-500-600-700-800-1000.

We are looking forward to your participation!

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By maroonrk, history, 4 months ago, In English

We will hold AtCoder Regular Contest 151.

The point values will be 300-500-600-700-700-1000.

We are looking forward to your participation!

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By maroonrk, history, 4 months ago, In English

We will hold AtCoder Regular Contest 150.

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

We are looking forward to your participation!

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By maroonrk, history, 4 months ago, In English

We will hold AtCoder Regular Contest 149.

The point values will be 300-500-500-700-700-900.

We are looking forward to your participation!

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By maroonrk, history, 5 months ago, In English

We will hold AtCoder Regular Contest 148.

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

We are looking forward to your participation!

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By maroonrk, history, 5 months ago, In English

We will hold AtCoder Regular Contest 147.

The point values will be 300-500-600-700-800-1100.

We are looking forward to your participation!

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By maroonrk, history, 5 months ago, In English

We will hold AtCoder Regular Contest 146.

The point values will be 300-500-600-800-800-1200.

We are looking forward to your participation!

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By maroonrk, history, 6 months ago, In English

We will hold AtCoder Grand Contest 058. This contest counts for GP30 scores.

The point values will be 400-700-900-1000-1400-2000.

We are looking forward to your participation!

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By maroonrk, history, 6 months ago, In English

We will hold AtCoder Regular Contest 145.

The point values will be 400-500-600-700-800-1200.

We are looking forward to your participation!

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By maroonrk, history, 7 months ago, In English

We will hold AtCoder Regular Contest 144.

The point values will be 300-400-600-700-800-900.

We are looking forward to your participation!

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By maroonrk, 7 months ago, In English

First of all, I have to say sorry for the vacancy of AGCs.

I'm confident in the style of AtCoder problems, but I have to admit that I was too strict; when I found a problem that was interesting but had a tiny flaw, I didn't try to use it in AGCs. In fact, I received several messages that some ARC problems are good enough for AGCs. If people who are stronger than me say that, what is my severe threshold for? Therefore, I'll be looser in selecting problems. It isn't such a big change that ARC becomes AGC. However, with the new policy, I could have made a few more AGCs in the first half of this year.

Now let's get down to the main subject: Call for Tasks. There were a few non-Japanese AGC writers, but the procedure of contest proposals was obscured. I want to make it public here. Please follow the following steps:

  • Come up with tasks for AGCs. It is desirable that you have ideas for a whole AGC set, but it's OK to have only hard problems.
  • DM me, and show me that you can possibly write AGCs. For example, I'll be convinced if
    • You are (ex-)LGM.
    • Your past problems are nice to me. (Tell me your masterpiece!)
    • Or you have some achievements like GCJWF, IOI/IMO gold, etc.
  • I'll grant you access to the problem submission interface of AtCoder. Please submit tasks there!

FAQ:

Q. What kind of problems are welcome/unwanted.
A. I'd love to have ad-hoc problems. I don't like implementation-heavy or knowledge-oriented problems. Data structures are OK as long as implementation<<<thinking.

Q. How much rejection rate should I expect?
A. It highly depends on how your "taste" is similar to mine. For some, I don't often reject proposals, while for others I keep complaining. Please check past AGC problems to see where you stand on.

Q. Why not allow ARC submissions?
A. Currently I check ARC/AGC proposals alone, so I'll be too busy to check additional ARC submissions.

Q. What happens when a problem gets rejected?
A. You are free to use it elsewhere. You may also write an ARC if you want.

Q. What's the fee?
A. 400000 JPY (subtracted by the tax) for one AGC. We can also pay for testers.

Hope to see your submissions and more AGCs!

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By maroonrk, history, 7 months ago, In English

What if your solution got TLE due to denormal numbers? Would you add if(val<eps)val=0 everywhere? Today I found a simpler fix: let's include #include <xmmintrin.h> and insert _MM_SET_FLUSH_ZERO_MODE(_MM_FLUSH_ZERO_ON); at the beginning of the main function.

Example Problem

TLE Submission

AC Submission

I confirmed this magic works on AtCoder, Codechef, Yandex, and, of course, on Codeforces.

Since it's written on the Wikipedia page, I won't be surprised if this is a well-known trick in some countries. However, I and my friends haven't heard of this, so it must be worth sharing.

Note that I know nothing about what exactly this snippet does, and I'm happy to hear from computer experts what the possible defects it has if such exist.

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By maroonrk, history, 7 months ago, In English

We will hold AtCoder Regular Contest 143.

The point values will be 300-500-600-700-700-1200.

We are looking forward to your participation!

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By maroonrk, history, 8 months ago, In English

We will hold AtCoder Regular Contest 142.

The point values will be 300-400-500-800-900-1000.

We are looking forward to your participation!

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By maroonrk, history, 8 months ago, In English

We will hold AtCoder Regular Contest 141.

The point values will be 400-500-600-700-700-1100.

We are looking forward to your participation!

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By maroonrk, history, 9 months ago, In English

We will hold AtCoder Regular Contest 140.

The point values will be 300-400-500-700-800-900.

We are looking forward to your participation!

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By maroonrk, history, 9 months ago, In English

We will hold AtCoder Grand Contest 057. This contest counts for GP30 scores.

The point values will be 400-700-1100-1100-1400-1800.

We are looking forward to your participation!

This is the first contest in the 2022 season that counts for the GP30 race. We are planning to invite top runners of the race to WTF 2023, but we still haven't decided on the details of the Finals. We will closely watch the domestic and international situations and consider when and how to hold the Finals. We are also trying to find a way to hold unfinished WTF 2020, 2021, and 2022.

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By maroonrk, history, 9 months ago, In English

We will hold AtCoder Regular Contest 139.

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

We are looking forward to your participation!

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By maroonrk, history, 10 months ago, In English

We will hold Daiwa Securities Co. Ltd. Programming Contest 2022 Spring(AtCoder Regular Contest 138).

The point values will be 400-500-600-700-1000-1000.

We are looking forward to your participation!

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By maroonrk, history, 11 months ago, In English

We will hold AtCoder Regular Contest 137.

The point values will be 300-400-600-700-800-1100.

We are looking forward to your participation!

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