By flamestorm, 35 hours ago, In English

Hej, Codeforces!

mesanu, SlavicG and I are very excited to invite you to Codeforces Round 937 (Div. 4)! It starts on Mar/28/2024 17:35 (Moscow time).

The format of the event will be identical to Div. 3 rounds:

  • 5-8 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 (but the rating will be recalculated for all with initial ratings less than 1400 or you are an unrated participant/newcomer).

We urge participants whose rating is 1400+ not to register new accounts for the purpose of narcissism but to take part unofficially. Please do not spoil the contest for the official participants.

Only trusted participants of the fourth 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 fourth 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 1400 or higher in the rating.

Regardless of whether you are a trusted participant of the fourth division or not, if your rating is less than 1400 (or you are a newcomer/unrated), then the round will be rated for you.

Thanks a lot to the testers: erekle, vladmart, nskybytskyi, Vladosiya, KrowSavcik, Dominater069, LucaLucaM, MADE_IN_HEAVEN, tvladm, nor.

We suggest reading all of the problems and hope you will find them interesting. Good luck!

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By Una_Shem, history, 3 days ago, In English

Hello, Codeforces!

Have you heard about TON Tact Smart Challenge #2? It's an amazing competition organized by our title sponsor, the TON Foundation in their ecosystem.

This challenge is designed to engage participants in creating a decentralized social network prototype utilizing the Tact smart contract language. The project consists of five stages, each aimed at implementing a core feature of the social network, from user profiles to decentralized management.

We encourage the Codeforces community to participate in this contest. Dive deep into the world of TON Blockchain and explore the limits of what's possible.

Challenge starts on March 25, and lasts until April 3. To enter the challenge, register through @smartchallengebot. You'll receive all the essential details, including start times, submission guidelines, and insights into the challenge stages.

For more information, visit this page.

TON Tact Smart Challenge #2 →

The scoring system is simple:

Each stage can bring you a max of 6 points. You get 5 points for solving a stage. You get an extra point if you solve it without using any gas.

Minimum amount of points to be eligible for the prize is 6 points.

Prizes:

  • $7,000 in TON — The top 15% of eligible participants
  • $7,000 in TON — The middle 30% of eligible participants
  • $6,000 in TON — The bottom 55% of eligible participants

Impressive, right? Hurry up and join!

Good luck!

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By dario2994, 9 days ago, In English

The European Championship 2024 will take place on the 24th of March in Prague. The top teams from the European ICPC regionals CERC, NWERC, SEERC, SWERC will compete for the title of European champions. It is the first edition of this ICPC super-regional.

The mirror contest European Championship 2024 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) will be held on Codeforces at Mar/24/2024 13:00 (Moscow time) and will last 5 hours.

The mirror contest will contain the same problems as the official competition.

I am the chief judge for the competition and I want to thank:

  • The amazing set of judges who proposed and prepared the problems: antontrygubO_o, bicsi, Giove, Martin Kacer, MZuenni, Petr.
  • Our beloved tester ksun48 who showed us that our perception of the difficulties was not exactly spot on...
  • Our beloved proofreader Philae for proofreading the statements.
  • Everyone involved in the organization of EUC. In particular our director Boba Mannová, and Fernando Silva, Václav Herman, Ondřej Votava, Jan Kubr, Jan Baier.
  • The developers of DOMjudge, the contest system used in the official contest.
  • MikeMirzayanov for Polygon (that we used to prepare the problems) and for letting us host the mirror on Codeforces.

I invite you to participate in the contest and I hope that you will like the problems.

On the difficulty
The contest features problems with difficulties from div1A to div1E. It should be enjoyable for many, and challenging even for the strongest teams in the world.

Rules

  1. The contest is unrated, so your codeforces rating will not be affected.
  2. The scoring is ICPC-style: teams are first sorted by number of problems solved, then the time-penalty is used as a tie-break. An incorrect submission gives a 20 minutes penalty.
  3. We encourage participation as a team.
  4. If you are participating in a team, we encourage you to use only one computer for coding the solutions (as in an ICPC contest). Regarding using templates, googling, and copy-pasting code: feel free to do it.
Rationale of rule 4.

UPDATE: We hope you liked the problems!

Congratulations to the winners, and especially to the first two teams for AK:

  1. dw my perception of the difficulties was not exactly spot on: tourist, ecnerwala.
  2. xinyoudui: PubabaOnO, orzdevinwang, jqdai0815
  3. MIPT: Yolki-palki: Tikhon228, Pechalka, Kapt
  4. Captain take me!: crazy_sea, A_zjzj, 275307894a
  5. Beyond Three Wolves: Kevin114514, CrTsIr, Atomic-Jellyfish
  6. HSE: FFTilted: Kirill22, Ormlis

We uploaded the editorial of the contest.

Tune in to ICPCLive to see the closing ceremony and find out how the onsite teams did at 18:00 CET!

UPDATE 2:

Congratulations to the medalists of the onsite contest:

  1. Warsaw Eagles 2024 — University of Warsaw (the only team with 9 problems)
  2. Zagreb 1 — University of Zagreb
  3. KNU_0_GB_RAM — Taras Shevchenko National University of Kyiv
  4. ELTE 1 — Eötvös Loránd University
  5. UWr 1 — University of Wroclaw
  6. ENS Ulm 1 — École Normale Supérieure de Paris

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By yunetive29, history, 10 days ago, translation, In English

Hola, Codeforces!

We are pleased to invite you to participate in Codeforces Round 936 (Div. 2), which will start on Mar/22/2024 17:35 (Moscow time).

The round was prepared by exhausted, max0000561, azureglow and myself.

This round will be rated for participants whose rating is below 2100. Participants with higher ratings may participate out of the competition.

You will be given 6 problems and 2 hours to solve them. We hope you find them interesting.

We would like to thank:

Special thanks to KoT_OsKaR and teraqqq for their help in creating tasks.

Good luck on the round and high rankings to everyone!

Score Distribution: 500−1000−1500−1750−2250−2750.

UPD: The date of the round has been changed to avoid interference with a competition on another platform.

UPD: Editorial

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By chenjb, 9 days ago, In English

Hello everyone, we are happy to announce the 2nd Universal Cup Semifinal and the 2024 Universal Cup Summer Summit.

In Season 2, thanks to everyone's support and efforts from our staff, there was a lot of progress compared to Season 1. We have over 3000 teams registered and so far we have scheduled over 30 stages in this season. We also managed to implement a registration webpage and host all kinds of contests on our platform, including the run-twice contest, the prime contest and the challenge contest. We also reached many agreements with Huawei about future cooperation, including the most exciting part: the onsite final. (Cooperation between Universal Cup and Huawei)

In the 2024 ICPC Latin American Championship, Universal Cup was invited to run the Huawei Challenge as a major part of the event. Our co-president Jingbang also gave a brief introduction of Universal Cup during the event to all the participants and coaches.

We still have more things coming! We have just finalized the rules for selecting the 2nd Universal Cup Final teams. The 2nd Universal Cup Semifinals will take place online, in order to select teams for the Final Contest. The contest is scheduled on one of the last two weekends of June (June 23 or 30). In addition, we have decided to host a special event, the 2024 Universal Cup Summer Summit in June. Supported by Huawei, we plan on inviting 10 teams to the wonderful city of Cancun, Mexico. The event will last around 5 days, including an onsite competition using the semi-final contest, a city tour, and some other activities. All fees will be covered by us. The exact schedule will be announced soon.

We want to express our gratitude again to everyone, especially problem-setters who have shared their wonderful contests with us. We are also planning to design souvenirs and prizes which will go to our contributors and participants, so stay tuned!

Here are the rules for the semifinal and the summer summit.

Details

Universal Cup

2024.3.19

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By Kirill_Maglysh, history, 10 days ago, translation, In English

Pay attention to the unusual round start time.

Hello, Codeforces!

Codeforces Round 935 (Div. 3) will start at Mar/19/2024 11:05 (Moscow time). The problems are expected to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have a rating of 1600 or higher, can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ICPC). Thus, solutions will be judged on preliminary tests during the round, and after the round, it will be a 12-hour phase of open hacks.

You will be given 8 problems and 2 hours and 15 minutes to solve them.

Note that the penalty for the wrong submission in this round is 10 minutes.

Remember, that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory 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, then the round will be rated for you.

The problems are based on VKOSP.Junior. Authors: Kirill_Maglysh, NToneE, Gadget.

We would like to thank:

  1. Vladosiya for coordinating the round.

  2. nigus, Gheal, KKT_89, Noinoiio, systy, FBI, SiERic, moonpie24, nik.danilov, SashaT9, Pa_sha, FedShat, an_na, khaser, Ghevar, Boris_Ber, PUFL, blook, yakuri354, iluminat_Btopou_AkkayHT for testing.

  3. gurovic for improving the quality of the statements.

  4. MikeMirzayanov for Polygon and Codeforces platforms.

Всем удачи!

UPD: Editorial is out

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By Dominater069, 2 weeks ago, In English

Hello Codech....err i mean Codeforces!

I invite you to participate in Codeforces Round 934 (Div. 1) and Codeforces Round 934 (Div. 2) which will start on Mar/16/2024 17:35 (Moscow time).

You will be given 6 problems and 2 hours 15 minutes to solve them in both divisions. Division 1 has $$$\textbf{2 subtasks}$$$, and Division 2 has $$$\textbf{1 subtask}$$$.

Joining us on the problem setting panel are:

I would like to thank MikeMirzayanov for platforms Codeforces and Polygon.

Please do read a few problems in advance at the very least. Especially with all the subtasks, it is strictly in your benefit to read and choose the problems you want to try. Good luck. We hope you enjoy the problemset.

Score Distribution will be posted soon.

$$$\textbf{UPD}$$$ : Score Distribution :
Div2 : 500 + 1000 + 1500 + 2250 + 2250 + (2250 + 2750).
Div1 : 500 + 1250 + 1250 + (1250 + 2000) + (2000 + 1500) + 4500.

$$$\textbf{UPD2}$$$ : Sorry for the issue with the queue towards the end. Hope you enjoyed the round.

$$$\textbf{UPD3}$$$ :
Div2 :
1) WanYuanShenWanDe
2) tzc___________________wk
3) kcodex
4) mily
5) Oinng123

Div1 :
1) tourist
2) jiangly
3) gyh20
4) Benq
5) ecnerwala

$$$\textbf{UPD4}$$$ : Editorial is out.

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By awoo, history, 2 weeks ago, translation, In English

Neapolis University Pafos

Hello Codeforces!

We are pleased to announce a new long-term partnership between Codeforces and Neapolis University Pafos. Now educational rounds will be supported by Neapolis University Pafos. Stay tuned and you will find out more soon.

On Mar/15/2024 17:35 (Moscow time) Educational Codeforces Round 163 (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, Roman Roms Glazov and me. Also, huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Big thanks to the testers shnirelman and Optoed for their valuable advice and suggestions! Special thanks to Vladosiya for his help with the round.

Good luck to all the participants!

UPD: Unfortunately, there were issues with the problem E judgement during the contest. There were only 18 participants affected by it, so the round stays rated. Rated participants whose verdict on problem E changed may request unrated participation (they have received the directions on how to change their participation to unrated). If you have not received any personal notifications about it in the contest dashboard, you have not been affected.

UPD2: Editorial is out

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

Hello, Codeforces!

On Mar/11/2024 17:35 (Moscow time) Codeforces Round 933 (Div. 3) will start.

You will be offered 7 problems, dedicated to the adventures of a restless mathematician, a programmer and just a funny character named Rudolf and his brother Bernard, and 2 hours 15 minutes to solve them. Problems have expected difficulties to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have a rating of 1600 or higher, can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ICPC). Thus, solutions will be judged on preliminary tests during the round, and after the round, it will be a 12-hour phase of open hacks.

Note that the penalty for the wrong submission in this round is 10 minutes.

Remember that only the trusted participants of the third division will be included in the official standings table. This is a compulsory 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, then the round will be rated for you.

Problems have been created and written by: vladmart, Sasha0738, t0rtik, Alexey_Parsh, Mordvin13, daha.002, Vladosiya and natalina.

We would like to thank:

  1. Vladosiya and Gornak40 for coordinating the round.

  2. MikeMirzayanov for Polygon and Codeforces platforms and helping prepare the problems.

  3. step_by_step, ashmelev for red testing.

  4. KseniaShk, senjougaharin for yellow testing.

  5. robotolev, Sochu for purple testing.

  6. dan_dolmatov, SashaT9, FBI, SpicyOctopus for blue testing.

  7. Gargera0, Matrosk1n, Alex_TULGU, Alenochka, gas for cyan testing.

  8. bugrova, Toy_mouse, ringku_ for green testing.

Good luck!

UPD: Because of the technical issue (see the post https://codeforces.com/blog/entry/126654), temporarily the only available C++ compilers are: C++14 (GCC 6-32) and C++17 (GCC 7-32).

UPD2: Editorial is posted.

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