Hello, codeforces ₍^. .^₎⟆

ABalobanov, Slamur and I are happy to invite you to participate in Codeforces Round (Div. 2), which will take place on Dec/11/2025 17:35 (Moscow time). This round will be rated for all participants with rating below 2100. You will be given 2 hours to solve 6 problems.

We are extremely grateful to these wonderful people

• The cutest coordinator FairyWinx.
• KAN, MikeMirzayanov for Codeforces and Polygon systems.
• Our amazing testers:
• Red-black testing: Um_nik.
• Red testing: A_G, Wansur, OG_Matveychick1, __baozii__, JoJo.
• Orange testing: aimoon, fractal, AlexanderGarifullin, Nyatl, antonis.white.
• Violet testing: dmkozyrev, yanb0, KiruxaLight, wuhudsm, Mosyagin.
• Blue testing: InsomniaT, atayawa, void_slowdown, kenzhik, rockoff, suharius, R1nixi.
• Green testing: emirhanbanan, ad1let17.

Score distribution:

We sincerely hope that you will enjoy the problems!

Hello, Codeforces!

We are happy to invite you to an exciting online event: ICPC 2025 Online Winter Challenge powered by Huawei, which will start on December 26, 2025 11:00 UTC (UTC+0). In this Challenge, you will have a unique chance:

• to compete during 16 days online challenge
• to solve 1 exciting problem prepared by Huawei
• to win amazing prizes from Huawei!

As a special prize, Huawei together with ICPC Foundation will provide the travel and an invitation to the 50th Annual ICPC World Finals in a guest role!

Everyone is welcome to participate. It is an individual competition.

Start: December 26, 2025 11:00 UTC (UTC+0)

Finish: January 11, 2026 10:59 UTC (UTC+0)

Prizes

Challenge Rules and Conditions

By participating in this Challenge, you agree to the Conditions of Participation and Challenge Rules. If you cannot access this document, please email [email protected]

Good luck, we hope this will be fun!

We hope you'll enjoy this complex yet very exciting Challenge!

Hi Codeforces!

On Dec/06/2025 11:15 (Moscow time) we will hold Codeforces Round 1069 (Div. 1) and Codeforces Round 1069 (Div. 2). Note the unusual starting time!

The harder problems of this round are based on the problems from the Final round of Yandex Cup 2025, Algorithms track, that will be held at the same time.

The problems are authored by lait1103, heesooyaam, I_love_kirill22, LeoPro, isaf27, elshiko, Flyce with guest problems from napstablook, sunkuangzheng, and great help from Vladithur, Dominater069, and tourist.

I'd like to thank Um_nik, Akulyat, okwedook, Merkurev, conqueror_of_tourist, Dominater069, ntherner, Limitiym, Iguanado for testing the round, and MikeMirzayanov for the Polygon and Codeforces systems.

Because the official Yandex Cup Finals ends later than the round on Codeforces, the upsolving, solutions, and test cases will be closed until the end of the onsite contest, roughly 3 hours after the end of the Codeforces round. It is also forbidden to discuss the problems publicly until the end of the onsite round. Any comments here concerning the problems will be removed.

P.S. Same as with many rounds based on onsite contests, you can expect that the difficulty curve may be different from the one typical for Codeforces rounds. This is mostly connected with the limited amount of testing we can do to avoid problem leakage, and with the limited choice of problems. Nevertheless, I believe that it's better to have a round than not have one, and I hope you'll enjoy the problems!

Good luck!

Scoring distribution: you'll see in the contest.

UPD: there is live stream with problem discussions and comments here: https://www.youtube.com/watch?v=6R7iwYAXKLY

UPD2: Editorial.

Hello Codeforces!

We are glad to invite you to participate in Codeforces Round 1068 (Div. 2) on Dec/05/2025 17:35 (Moscow time).

This round is rated for all participants with rating below 2100. You will be given 6 problems and 2 hours to solve them. At least one problem will be interactive, so please make sure to read the guide for interactive problems before the contest.

In this contest, characters from four different anime series appear in some of the problem statements (including the one my avatar is from). Can you guess which series they are?

We would like to thank:

• paulzrm, HHH666666, chen_zida and HugeWide for writing the problems.

• Error_Yuan for coordinating the round.

• MikeMirzayanov for great Codeforces and Polygon platforms.

• Alexdat2000 for translating the statements into Russian.

• 0htoAi, A_G, Arpa, Caylex, Kowngx, Mitsukasa_Ayase, NanamiChiaki_, ShmilyTY, TKXZ133, Unlimited_zero, _istil, liruisi, real_Catalan1906, rui_er, temporary1, wuhudsm for testing the round (sorted by dictionary order).

• You

  for participating in this round.

The score distribution will be announced later.

Good Luck & Have Fun!

UPD1: Score Distribution: 500 — 1000 — 1250 — 1750 — 2250 — 3000.

UPD2: In this round, hacks will be disabled on problems A, B, C, D, and E. We will have pretests = systests in these problems. Hacks will be enabled on F as usual, and we will have systests = pretests + hacks.

UPD3: The editorial is out.

UPD4: Congrats to the winners!

Div. 1:

• maspy
• zltzlt
• TKT_YI
• ahmetalp
• Egor

Div. 2:

• Anlybt
• IHaveInt (disabled)
• votranngocvy
• omoch1
• Mohamed_Reda
• DSCS2009

Hi everyone!

Supported by

The OCPC (Osijek Competitive Programming Camp), an award-winning camp for university students to prepare for ICPC and other coding competitions, is back again this winter, on January 24 — February 1, 2026!

The camp is organized by adamant and -is-this-fft- on the premises of the University of Osijek in Osijek, Croatia.

The camp is inspired by various competitive programming camps that we attended during our active years in ICPC, and is aimed to help college students prepare for ICPC regional contests and finals. The camp will consist of 7 ICPC-style contests and 2 days off.

Details

The participation fee for both online and onsite participants is 198€ per team.

Similar to previous camp editions, the fee does not include regular meals, travel or accommodation.

We support and empathize with those affected by the ongoing war in Ukraine, therefore we offer a free participation for affected individuals and teams affiliated with Ukrainian institutions.

Additionally, we would like to offer the following discounts:

• Early bird discount: We offer a reduced participation fee of 147€ per team if you register before December 14, 2025.
• Hardship discount: We offer fee reduction to 99€ per team, on request, if you feel that default fee makes it a financial burden for you.

We do not require any proof or documentation when using the hardship option, and trust your self-assessment. Nevertheless, we ask you to be mindful when using it, as we still have to rely on participation fees as the baseline for running the camp.

The expected starting time for the contests is 10am CET. For remote participants, it is still a preferred starting time, but we will make accommodations for virtual participation at a later time, when necessary.

Most of our contests are originally developed for the camp. A small number of contests may be based on previous contests that have not been released to the general public. If you have seen some problems of a contest before, you can't participate on that day. We will privately contact participants who might be affected.

After the camp, we will have a silence period during which camp materials will not be released to the public. We ask participants not to discuss the problems in public unless they obtained an explicit permission from contest authors.

If you would like to get a feel of the contests, you can find links to some of the previously published camp contests here.

If you have any questions about the camp, please feel free to send us an email, or join our Discord server!

Participants

If you are interested in participating, please fill the form here.

Register before December 14, 2025 to receive an early bird discount!

We ask you to register before January 17, 2026 if you want to participate remotely and before January 10, 2026 if you want to participate in Osijek. If you require a visa, please register as soon as possible, as it might take a few weeks to receive (depending on your location).

If your university or organization has a lively ICPC community that may be interested in attending the camp, and you have some contacts of people in charge (e.g. coaches) we would highly appreciate if you could share some details in a direct message to me. Thanks!

Problem authors

We'd like to thank and praise the authors of the contests in the camp:

• AmirrzwM — ICPC World Finalist (2024, 2025), author of Codeforces and Rayan Rounds, and INOI (Iranian National Olympiad in Informatics) Silver Medalist.
• MohammadParsaElahimanesh — Author of Codeforces and Rayan Rounds, INOI Silver Medalist, and top problem solver on Quera.
• Arpa — two times ICPC World Finalist and former Codeforces Contest Coordinator.
• -is-this-fft- — ICPC 2019 world finalist, Google Hash Code 2020 finalist.
• Pyqe — IOI gold medalist, author of IOI 2024 Nile and Tree.
• Kinon — IMO bronze, silver, and gold medalist.
• gloria_mundi, burg113 — 2025 GCPC winners, 2024 and 2025 NWERC silver medalists.
• SGColin — Problemsetter for ICPC Asia East contests. Universal Cup Staff.
• Claris — ICPC 2017 and 2018 world finalist. Top contributor of QOJ.
• marks39, ssk4988 — 2025 North America Big South champions, participants in the 2025 NAC and WF. Currently coaching for UCF.
• KCPC — A Competitive Programming Club of Kyoto Univ, which is a regular at the WF.

You can find more details about contest rules and technical setup on the website.

Special thanks

Finally, we say special thanks to

• our sponsors, who make the camp possible;
• ICPC foundation for their help and support;
• Codeforces for support and guidance;
• eolymp for providing an online judge for the contests;
• Mathos for the invaluable help and providing a physical location for the camp.
• BigBag for consistently making very useful combined scoreboards at https://acmallukrainian.ho.ua/camps/.

UPD: The contest platform is up! Everyone can now register through the platform!!!!

UPD: The champion will be invited as a guest (with full accommodation and travel expense covered) to the 2026 Universal Cup Finals. The champion will be awarded at the time and will be invited to participate in the onsite challenge.

Hello Codeforces! We are very happy to announce that, after months of preparation, we have finally scheduled our first online challenge from December 17th to December 24th! Sponsored by Huawei, we have prepared valuable prizes for everyone to compete for! Although many details are still to be finalized, we are too excited to share the following details with you as an early Christmas gift!

• Contest Name (Subject to Change): The 2025 Universal Cup Online Challenge Sponsored by Huawei

• Platform: Universal Cup Challenge Platform (Powered by Hydro）

• Date: December 17th &mdash 20:00; December 24th 20:00（UTC+8)

• Prize:

As always, the Universal Cup is dedicated to bridging the gap between the competitive programming community and the industry. This online challenge is an attempt that we are counting on. We will do our best to make it as good as possible, and we call on everyone to support this challenge by participating!

Since we hope everyone to focus on the challenge, there will be no regular stage on December 21st. The registration details will be announced in early December. We will be posting another blog (on Codeforces, the Official Website, and other threads) to specify the rules. Please stay tuned!

To learn more about Universal Cup, please visit our official website. The 4th season is ongoing now.

The Universal Cup is sponsored by

Good day Codeforces ✨

We are excited to invite you all to Codeforces Round 1067 (Div. 2), starting at Nov/29/2025 17:35 (Moscow time).

This round features 6 problems to be scored in 2 hours, with a few problems including multiple parts. All tasks were authored and prepared by koderkushy and me. This round will be rated for all participants with rating below 2100. Take a look at all the problems, we hope you enjoy the challenge! 🚀

We extend many thanks to our team for helping make this round possible:

• abc864197532 for his excellent coordination.
• KAN for preliminary review.
• Testers lineup: Dominater069, dreamoon_love_AA, Fysty, amano_hina, _istil, __baozii__, IceKnight1093, CoderAnshu, Pols_Agyi_Pols, sv1shan, piyush_pransukhka, a.out, BiggestOtaku, Bucketsmith, -firefly-, satyam343, plAtEaUpUs, omsincoconut, snasibov05, homelanderrr, _helloLad, BladeRunner, deneribeiro10, Rafio, balakrishnan, UniversalAdmin
• Alexdat2000 for translation problem statements into Russian.
• MikeMirzayanov and KAN for lovely platforms Codeforces and Polygon.
• And of course, you, for taking part! 💛

Score Distribution: $$$500-1250-1500-2000-2750-(2500+1000)$$$ 🏆

UPD: Congrats to the winners!

• 🥇 StarSilk
• 🥈 Noobish_Monk
• 🥉 Mon_ster
• BurnedChicken
• ec3e9a2e8e

Kudos to antontrygubO_o for almost getting to the intended solution of F2 in contest!

UPD 2: The editorial is out.

Hello Codeforces!

The series of Educational Rounds continues thanks to the support of the Neapolis University Pafos.

On Nov/28/2025 17:35 (Moscow time) Educational Codeforces Round 185 (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, Maksim FelixArg Novotochinov 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

Ciao, Codeforces! We're glad to invite you to take part in Codeforces Round 1066 (Div. 1 + Div. 2), which will start on Nov/23/2025 12:35 (Moscow time). You will be given 9 problems and 3 hours to solve them in both divisions. The round will share some problems with The 2025 ICPC Southwestern Europe Regional Contest (SWERC) 2025.

Note the unusual starting time.

Some of the problems might be interactive, so please read the guide for interactive problems if you are not familiar with it.

The problems were authored and prepared by KLPP and me.

We would like to thank

• Dominater069 for his 💭 💡 🎈 coordination;
• Alexdat2000 for Russian translation;
• dario2994 for VIP testing;
• Geothermal, MrBrionix, xiaowuc1, SmolBrain, awoo, Intellegent, IceKnight1093, MridulAhi, Adam_GS, A_G, Sana, Virv, ha___il, chromate00, hashman for testing;
• {Rafi22, surgutti, Krzychuo}, {Akulyat, arzhantsev64, okwedook}, {AlperenT, izhang, Extile} for team testing;
• the SWERC judges team for judging the problems;
• MikeMirzayanov for creating Codeforces and Polygon;
• dario2994 for creating pol2dom, a tool to convert problems from the Polygon format to the SWERC format with minimal effort.

The score distribution will be announced after the onsite contest starts.

We hope you'll like the problemset!

UPD 1: The score distribution is as follows:

$$$500 + 1000 + 1500 + 1500 + 2000 + 2500 + 3000 + 3750 + 4000$$$

UPD 2: Upsolving & viewing of solutions and tests will be closed until the end of the onsite contest (13:30 UTC, 1 hour after the Codeforces round ends). Please also refrain from discussing the problems in public until that time.

UPD 3: Congratulations to the winners:

• Rank $$$1$$$ : tourist
• Rank $$$2$$$ : jiangbowen
• Rank $$$3$$$ : ksun48
• Rank $$$4$$$ : PEIMUDA
• Rank $$$5$$$ : Radewoosh (Only solve on problem I!)
• Rank $$$6$$$ : VivaciousAubergine
• Rank $$$7$$$ : qiuzx
• Rank $$$8$$$ : Rainbow_qwq
• Rank $$$9$$$ : Rubikun
• Rank $$$10$$$ : maspy

UPD 4: The editorial is out.