By m3tr0, 10 hours ago, translation, In English

Hi Codeforces!

We would like to invite you to participate in Codeforces Round 984 (Div. 3) on Nov/02/2024 17:35 (Moscow time). You will be given 7 or 8 problems and 2 hours and 15 minutes to solve them. The penalty for an incorrect submission will be 10 minutes. There may be interactive problems in the round.

The round will be ruled according to the standards of educational rounds (extended ICPC). Thus, solutions will be judged on preliminary tests during the round, and after the round, there will be a 12-hour phase of open hacks. After open hacks all accepted solutions will be rejudged on successful hacks. We've tried to make decent tests — just like you, we'll be upset if you have dropped solutions after the end of the contest.

Reminder that only trusted Division 3 competitors will be included in the official results table. This is a forced measure to combat unsportsmanlike behavior. To qualify as a trusted Division 3 competitor, one must:

  • participate in at least five rating rounds (and solve at least one problem in each of them)
  • not have a point 1900 or higher in the rating.

Whether you are a trusted Division 3 participant or not, if your rating is less than 1600, the round for you will be rated.

The tasks were authored and prepared by a team consisting of Seny, eugenechka.boyko.2_0-0 and myself.

The round is based on the recent Lipetsk Team Programming Olympiad for school students. Please note that if you are a participant of the Olympiad, you are not allowed to participate in this round. Thanks to the coordinator of this Olympiad myav and the author Small_machine, whose tasks were not included in this round due to their high complexity.

We thank very much:

We hope you find the promlems interesting. Good luck!

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By Sagita_Phoenix, history, 11 days ago, In English

Hello Codeforces!

$$$\newline$$$

From AkiLotus

It's been a while, today AkiLotus and I are delighted to invite you to participate in Codeforces Round 983 (Div. 2). This round will be rated for all participants with a rating lower than 2100.

Our round will start on Nov/01/2024 17:35 (Moscow time). You will be given 6 problems and 120 minutes to solve them.

This contest is a collaboration between AkiLotus, his friends and Code Mely, a Vietnamese community and an individual passionate about Computer Science. Reach out to us here.

Special thanks to:

$$$\newline$$$

Score distribution: $$$500 - 750 - 1250 - 1750 - 2250 - 3000$$$

Happy coding! Our chicken nuggets and Fubao bless you.

UPD1: Editorial is published.

UPD2: Congratulations to the winners!

Div. 1 + Div. 2:

  1. Nachia
  2. arvindf232
  3. peti1234
  4. turmax
  5. superguymj
  6. Rubikun
  7. ksun48
  8. potato167
  9. BurnedChicken
  10. Vincella

Div. 2 (official):

  1. Vincella
  2. SUPERLWR-beta
  3. BlackLily
  4. leolin0214
  5. TAIYANGFENG
  6. xiaowangba
  7. piasticOuO
  8. Nikephoros2Phocas
  9. SkyWave2024
  10. zsj6315

First solves:

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By awoo, history, 5 days ago, translation, In English

Neapolis University Pafos

Hello Codeforces!

The series of Educational Rounds continues thanks to the support of the Neapolis University Pafos. They offer a BSc in Computer Science and AI with JetBrains Scholarships. Gain cutting-edge skills in AI and machine learning, preparing you for high-demand tech careers. Curious? Join the livestream on Tuesday, October 29 at 5:00 pm UTC to learn about the CSAI program’s curriculum, course structure, scholarships, student internships, and their hands-on learning approach.

Want more experience in coding and math competitions?
JetBrains Youth Challenge returns in November 2024!

Who can join?
Ages 13–18
Anyone currently enrolled in secondary education
Register now

On Oct/28/2024 17:35 (Moscow time) Educational Codeforces Round 171 (Rated for Div. 2) will start.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6 or 7 problems and 2 hours to solve them.

The problems were invented and prepared by Adilbek adedalic Dalabaev, Ivan BledDest Androsov, Maksim Neon Mescheryakov and me. Also, huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Good luck to all the participants!

UPD: Editorial is out

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By Hori, 4 weeks ago, In English

Hello, Codeforces!

We are pleased to announce the resumption of the Global Rounds. Thanks to XTX Markets for supporting the initiative! In 2024, we will hold 4 such rounds. The series results will take into account the best 3 participations out of 4.

On Oct/27/2024 17:35 (Moscow time) we will host Codeforces Global Round 27.

Codeforces Global Round 27 marks the third round in the 2024 series of Codeforces Global Rounds. These rounds are open and rated for everyone.

The prizes for this round are as follows:

  • The top 30 participants will receive a t-shirt.
  • 20 t-shirts will be randomly distributed among participants ranked between 31 and 500, inclusive.

The prizes for the 4-round series in 2024:

  • In each round, the top-100 participants get points according to the table.
  • A participant's final score will be the sum of the points they earned in their 3 highest-placing rounds.
  • The top 20 participants across the series will receive sweatshirts and placement certificates.

We extend our gratitude to XTX Markets for supporting the global rounds initiative in 2024!

The 8 problems were authored by our 8 authors: Benq, lunchbox, oursaco, sum, willy108, Hori, turtletortles, and last but not least ChatGPT.

We would also like to thank:

Round Information:

  • Duration: 180 minutes
  • Number of problems: 8 problems with 1 subtask
  • Score distribution: 250 — 500 — 1000 — 1500 — 2000 — 2250 — (2250 — 2000) — 4500

We look forward to your participation!

UPD: Congrats to the winners

  1. Kevin114514
  2. 275307894a
  3. jiangly
  4. JoesSR
  5. ksun48
  6. turmax
  7. dXqwq
  8. hos.lyric
  9. Rewinding
  10. jiangbowen

UPD2: First solves

A: dXqwq
B: hos.lyric
C: dorijanlendvaj
D: riantkb
E: turmax
F: taeyeon_ss
G1: taeyeon_ss
G2: Kevin114514
H: orz (only in contest solve!)

UPD3: Editorial

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Announcement of Codeforces Global Round 27
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By myst-6, history, 13 days ago, In English

Hello Codeforces! Me and yud08 are excited to invite you to take part in Codeforces Round 982 (Div. 2), which starts on Oct/26/2024 17:35 (Moscow time). You will be given 5 problems and 2 hours to solve them. Two problems are divided into two subtasks.

This round will be rated for all participants whose rating is strictly below 2100.

The problems were authored by me and yud08, and prepared by me.

We would like to thank:

We hope you enjoy the problems!

Score Distribution: $$$500 - 1000 - 1250 - (1250 + 1000) - (2000 + 1000)$$$

We actually wanted to continue the trend of posting photos of contest writers, but we could only find one photo containing both of us, which was a group photo that we took with some other UK informatics people! (I'm the one in the back of the picture who is wearing the MHC T-shirt and yud08 is the one whose head is popping out from the left side of the photo.)

20240921-153321

UPD1: Congratulations to the winners of the contests:

Div 1:

  1. jiangly
  2. neal
  3. SSerxhs
  4. A_G
  5. kotatsugame

Div 2:

  1. nathan_higgs
  2. purupurupururin
  3. Nonoze
  4. Hong_Meiling
  5. Nika_Tamliani

Also, first solves! (if any of these are wrong please let me know)

UPD2: Editorial is available here

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By FBI, history, 10 days ago, In English

Hello Codeforces!

I am pleased to invite you all to participate in Codeforces Round 981 (Div. 3), which will start on Oct/24/2024 17:35 (Moscow time).

The format of the event will be like any Div. 3 rounds:

  • 6-8 tasks;

  • ICPC rules with a penalty of 10 minutes for an incorrect submission;

  • 12-hour phase of open hacks after the end of the round (hacks do not give additional points)

  • after the end of the open hacking phase, all solutions will be tested on the updated set of tests, and the ratings recalculated

  • by default, only "trusted" participants are shown in the results table.

I encourage participants with a rating of 1600+ not to create new accounts but to participate unofficially.

Only trusted participants of the third division will be included in the official standings table. This is a forced measure for combating unsporting behavior. To qualify as a trusted participant of the third division, you must:

  • take part in at least five rated rounds (and solve at least one problem in each of them),
  • do not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600 (or you are a newcomer/unrated), then the round will be rated for you.

Also, it will be a round with unrated register. If you already registered as rated participant you can change registration type here.

I would like to thank

Good luck!

Upd: Editorial is out.

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By Ormlis, history, 2 weeks ago, In English

Hello, Codeforces! We're glad to invite you to take part in Codeforces Round 980 (Div.1, Div. 2), which will start on Oct/20/2024 12:05 (Moscow time). Note the unusual time of the round. Each division will have 6 problems and 2 hours to solve them. The round will be held according to the Codeforces rules and will be rated for both divisions.

The problems were authored and prepared by Mangooste, Tikhon228, adepteXiao, Artyom123, sevlll777, yunetive29, glebustim, Endagorion, isaf27 guided by Ormlis and Helen Andreeva.

The round is based on XXII Moscow Team Olympiad, high school students competition based in Moscow that is an elimination contest for All-Russian Team Olympiad. Also thanks to the authors of the Olympiad whose problems were not included in the round : vaaven, TeaTime, pakhomovee, TheEvilBird, ch_egor.

We would like to thank specially:

Great thanks to the testers: Kapt, SomethingNew, k1sara, Pekiban, automac, theRealChainman, marks39, cosenza, pengin_2000, Killever, perchuts, Endagorion, maomao90.

As well as the teams testing the main Olympiad: (RP-1, kostylevGO, PBBx0), (AgafonovArtem, blyat), (daubi, talant, alexxela12345), (tem_shett, crazyilian, sevlll777), (katyaporay, Igorbunov, Dart-Xeyter), Kirill22, (rama798, FlameDragon, egneeS), (MOHOXPOM, Goshix, shevnin_d), teraqqq, (Siberian, Um_nik), (kova1, Aleks5d), (makcvim, Silver_Fox), polosatic.

UPD1: Score distribution:

Div.2: 500 — 1000 — 1250 — 1750 — 2250 — 3000

Div.1: 500 — 1000 — 1500 — 2250 — 2750 — 3000

UPD2: Due to the official competition source codes of other participants will not be available for two hours after the end of the round.

UPD3: Editorial

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By cry, 3 weeks ago, In English

Haiii Codeforces ^_^

Note the unusual starting time. This round starts 30 minutes before the standard starting time.

vgoofficial and I are extremely excited to invite you to Codeforces Round 979 (Div. 2) on Oct/19/2024 17:05 (Moscow time). You will be given 7 problems and 2 hours and 15 minutes to solve them. One problem will be split into two subtasks. This round will be rated for all participants with rating below 2100.

This round is based on... absolutely nothing.

We would like to mention the following individuals for making the contest possible:

Score Distribution: $$$250 - 500 - 1000 - 1500 - 2000 - 2500 - (3000 + 1500)$$$

UPD: Editorial

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By awoo, history, 3 weeks ago, translation, In English

Neapolis University Pafos

Hello Codeforces!

The series of Educational Rounds continues thanks to the support of the Neapolis University Pafos. They offer a BSc in Computer Science and AI with JetBrains Scholarships. Gain cutting-edge skills in AI and machine learning, preparing you for high-demand tech careers. Curious? Check out the CSAI curriculum now. Limited scholarships available — don't miss your chance to study in Europe for free!

Are you looking to sharpen your skills and increase your chances of getting a scholarship? Join the free clubs for high school students from JetBrains:

On Oct/14/2024 17:35 (Moscow time) Educational Codeforces Round 170 (Rated for Div. 2) will start.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest, you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6 or 7 problems and 2 hours to solve them.

The problems were invented and prepared by Adilbek adedalic Dalabaev, Ivan BledDest Androsov, Maksim Neon Mescheryakov, Aleksandr fcspartakm Frolov and me. Also, huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Please note that the problems of this round partially intersect with the problems of the Qualification stage of the Southern and Volga Russian Regional Contest. If you took part in the qualification, please refrain from participating in the round.

Good luck to all the participants!

UPD: Editorial is out

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