| # | User | Rating |
|---|---|---|
| 1 | Benq | 3676 |
| 2 | Kevin114514 | 3659 |
| 3 | jiangly | 3640 |
| 4 | turmax | 3450 |
| 5 | tourist | 3382 |
| 6 | strapple | 3360 |
| 7 | Um_nik | 3354 |
| 8 | squareOf105 | 3348 |
| 9 | maroonrk | 3312 |
| 10 | idontwannadothis…e | 3191 |
| # | User | Contrib. |
|---|---|---|
| 1 | Qingyu | 156 |
| 2 | nik_exists | 151 |
| 3 | maspy | 149 |
| 4 | AmShZ | 145 |
| 5 | Um_nik | 143 |
| 6 | Errichto | 139 |
| 7 | BledDest | 136 |
| 8 | adamant | 135 |
| 9 | maroonrk | 132 |
| 10 | cry | 130 |
Hello everyone!
Today we announce that Codeforces now supports OpenID Connect — authentication protocol based on the OAuth 2.0. This allows third-party websites to implement logging in with Codeforces.
If you want to implement this for yourself, create an OAuth app in API settings.
Codeforces includes user's handle, current rating and avatar url as part of the id token.
Let us know if you hit any issues!
Hello Codeforces!
We are glad to invite you to participate in Codeforces Round 1042 (Div. 3), which will start on Aug/10/2025 17:35 (Moscow time). You will be given 2 hours and 15 minutes to solve 8 problems.
The problems are authored and prepared by -firefly-, efishel, Tobo, and __baozii__.
The round will be hosted by the rules of educational rounds (extended ICPC). Thus, all 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 the open hack phase, all accepted solutions will be rejudged on successful hacks. Also, note that there is no score distribution — rank will be determined by number of problems solved, followed by penalty; wrong submissions will incur the usual penalty of 10 minutes, following the rules of educational rounds.
As a reminder, only 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:
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 (unless you register unrated).
Also, note the rule restricting the use of AI. If you are caught breaking this rule, you will be thrown into -firefly-'s basement. For your own well-being, I suggest adhering to the rules.
We would like to thank the following people for helping make this round possible!
Good luck!
Announcement of Codeforces Round 1042 (Div. 3)
Hello, Codeforces!
We are proud to invite you to participate in Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2) which will be held on Aug/07/2025 17:35 (Moscow time).
The round will be rated for everyone. You will be given 8 problems, one of which is divided into two subtasks, and 3 hours to solve them. One of the problems will be interactive, so make sure to read the guide for interactive problems before the contest.
The problems are authored and prepared by Ali_BBN, Bahamin, _R00T, eren__, sweetweasel, and me.
We would like to thank:
Special thanks to [MVP] LMydd0225 for his invaluable help during testing!
The scoring distribution is below.
| A | B | C | D | E | F | G1 | G2 | H |
|---|---|---|---|---|---|---|---|---|
| $$$500$$$ | $$$1000$$$ | $$$1500$$$ | $$$2000$$$ | $$$2500$$$ | $$$3000$$$ | $$$2750$$$ | $$$2750$$$ | $$$4000$$$ |
Now, a few words from our sponsor!
At Atto Trading, we are a science-driven quantitative trading firm where engineers, quants, and researchers combine their efforts to engineer cutting-edge trading systems that execute in nanoseconds, powering decisions at the speed of light in the world’s most competitive market. Many of our team members started their journey on platforms like Codeforces. We are thrilled to announce our own round on Codeforces platform.
Follow the link below and complete the application form to explore career opportunities with us.
We prepared some exciting rewards for participants in this round.
If we encounter difficulties delivering your gift, we reserve the right to reimburse its value in cryptocurrency
Good luck!
UPD 1: Score distribution was released!
UPD 2: Editorial
UPD 3: Congratulations to the winners!
Announcement of Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2)
Hello, Codeforces! We're glad to invite you to take part in Codeforces Round 1040 (Div. 1) and Codeforces Round 1040 (Div. 2), which will start on Jul/31/2025 17:35 (Moscow time).
You will be given 6 problems and 3 hours to solve them in both divisions. Some problems will be divided into subtasks.
The problems were authored and prepared by me.
Some problems may be interactive. So please refer to the guide on interactive problems if you are unfamiliar with them.
We would like to thank
Good luck and have fun!
Score distribution:
Div.1: $$$500$$$ — $$$1000$$$ — ($$$750+750+750$$$) — $$$2000$$$ — $$$3000$$$ — ($$$2500+2500$$$)
Div.2: $$$500$$$ — $$$1000$$$ — $$$1250$$$ — $$$1750$$$ — ($$$1500+1500+1500$$$) — $$$4000$$$**
UPD 1: Editorial
UPD 2:
Congratulations to the winners!
Div.1:
Div.2:
Announcement of Codeforces Round 1040 (Div. 1)
Announcement of Codeforces Round 1040 (Div. 2)
🚀 Hello Codeforces — from Atto Trading!
We invite you to take part in our first round on Codeforces: Atto Round 1 (Codeforces Round 1041, Div. 1 + Div. 2). Join us on Aug/07/2025 17:35 (Moscow time) and test your skills by solving problems!
Atto — Named after 10⁻¹⁸. In our world, every nanosecond counts — trading happens faster than a blink.
Are you obsessed with optimization? Do you count nanoseconds like your code depends on it?
If so — we might have something in common. If you're passionate about low-level optimization, algorithmic thinking, and squeezing performance out of every cycle in C++, this is the kind of problem-solving you’ll love.
We’re Atto Trading, a science-driven quantitative trading firm where code is everything and every nanosecond matters.
Our team is a mix of engineers, quants, and researchers — many of whom started their journey on platforms just like this one. We engineer cutting-edge trading systems that execute in nanoseconds, powering decisions at the speed of light in the world’s most competitive market.
And we build them the same way you approach a hard Codeforces problem:
➡ With clean logic, performance in mind, and relentless iteration.
💡 Why It’s a Perfect Fit for Competitive Programmers
🧠 What You’ll Find at Atto:
Top The Ranks, Win The Rewards!
If we encounter difficulties delivering your gift, we reserve the right to reimburse its value in cryptocurrency.
🎯 We’re Hiring
Whether you’re just finishing university or already an experienced professional, we’d love to hear from you.
If your Codeforces graph trends sharply upward, or if you find joy in debugging what others call "impossible" – this might just be your next challenge.
If you're interested in job offers from our company, please fill out the form:
Good luck!
Hello Codeforces!
We are glad to invite you to Codeforces Round 1039 (Div. 2), which will take place on 27.07.2025 17:35 (Московское время).
The problems were created by I_love_Michel_Sardou, Richem, bestial-42-centroids, Yuuuuuuuuuuuuuuuuu and me.
We would like to thank:
Akulyat for coordinating our round and helping with the preparation of the problems.
antontrygubO_o, Adam_GS, JeanBombeur, Error_Yuan, Everule, prvocislo, KiKoS, Friedrich, mrthimote, Jasonwei08, arknave, mcfr, madlogic, kinnikuma, raphaelp, tibinyte2006, dssfsuper2, dazlersan1 and Thyl for testing.
MikeMirzayanov for the Codeforces and Polygon platforms.
You will have 2 hours to solve 6 problems.
Good luck!
UPD: The score distribution is 500 — 1000 — 1250 — 1750 — (1750+1750) — 4000.
UPD2: The editorial is out!
UPD3: Congratulations to the winners!
Div.1
Div.2
Announcement of Codeforces Round 1039 (Div. 2)
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. Limited scholarships available — don't miss your chance to study in Europe for free!
On Jul/22/2025 17:35 (Moscow time) Educational Codeforces Round 181 (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, Maksim FelixArg Novotochinov, Polina ifive Piklyaeva and me. Also, huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.
Big thanks to the testers shnirelman and Brovko for their valuable advice and suggestions!
Good luck to all the participants!
UPD: Editorial is out
Announcement of Educational Codeforces Round 181 (Rated for Div. 2)
Hello, Codeforces!
I am proud to invite you to Order Capital Round 1 (Codeforces Round 1038, Div. 1 + Div. 2), which will be held on Jul/19/2025 17:35 (Moscow time).
The round will be rated for everyone. You will be given 7 problems and 2 hours and 15 minutes to solve them.
All problems were authored by me.
I would like to thank:
cadmiumky and TheScrasse for coordinating the round,
Radewoosh, arvindf232, errorgorn, Adam_GS, Errichto, -XraY-, Marcin_smu, Rafi22, SergeiFedorov, Markadiusz, Dragos, VadymKa, freak93, Andrei_ierdnA, NemanjaSo2005, fwitt, ToxicPie9, madlogic, Porumb, ivgechu, stefdasca, tibinyte2006, lIlIlIlIIll, trraian, Buek, larush, lev1106 for testing,
Alexdat2000 for Russian translations,
MikeMirzayanov for Codeforces and Polygon.
Score distribution:
| $$$500$$$ | $$$1000$$$ | $$$1500$$$ | $$$2000$$$ | $$$2500$$$ | $$$3250$$$ | $$$4000$$$ |
And now, a few words about today's sponsor!
Order Capital is a team of engineers and researchers with a deep passion for algorithms, clean code, and well-crafted solutions. Many of their team members have a competitive programming background — with roots in ICPC, IOI, IMO, Code Jam, and Hacker Cup — so hosting their own Codeforces round is a particularly exciting milestone. They specialize in building high-performance systems for algorithmic trading, where every nanosecond matters.
Here’s the founder’s welcome post in case you missed it — plus info on current openings.
Considering joining the team or doing an internship? Hit the link and fill out the form — they’d love to hear from you!
🏆Prizes & Surprises:🏆
But that’s not all.
Top 10 — guaranteed, plus 20 lucky participants ranked between 11 and 200 will also get our surprise merch boxes!
Good luck, have fun, and don’t forget to apply if you're looking for your next challenge!
UPD: Editorial is up.
Announcement of Order Capital Round 1 (Codeforces Round 1038, Div. 1 + Div. 2)
Hello, Codeforces!
I am very excited to invite you to our contest Codeforces Round 1037 (Div. 3), which starts on Jul/17/2025 17:35 (Moscow time). You will be given 7 problems and 2 hours and 15 minutes to solve them.
The problems were authored by me, __rose, Pishka12, Chalishkan and I_HATE_MD_DM to solve and alter them.
The round will be hosted by the rules of educational rounds (extended ICPC). Thus, all 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 the open hack phase, all accepted solutions will be rejudged on successful hacks. Also, note that there is no score distribution — rank will be determined by number of problems solved, followed by penalty; wrong submissions will incur the usual penalty of 10 minutes, following the rules of educational rounds.
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:
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.
We would like to thank:
GL HF!
Also I would like to show you the beauty of our country's nature with the stunning backdrop of tourist Peak (3965m)!
Announcement of Codeforces Round 1037 (Div. 3)
Hello everyone!
I invite you to take part in Order Capital Round 1 (Codeforces Round 1038, Div. 1 + Div. 2).
My name is Igor Pyshkin. Throughout my academic career, I participated in a lot of programming and math competitions: I am the 2016 ACM ICPC World Champion and competed in the onsite finals of the Facebook Hacker Cup, Google Code Jam, and TopCoder Open. After completing my degree, I transitioned into a new field — high-frequency trading (HFT).
Four years ago, I founded my own HFT fund — Order Capital. Since then together with my colleagues I have been working really hard to reach the highest levels of the HFT industry. Launching this contest on Codeforces is quite special to me, as it is our first contest on the platform as a company.
I would like to thank the Codeforces team and everyone involved in the round preparation. Our internal testing team found the problems quite interesting, I hope you will enjoy them too.
We’ve prepared some cool prizes:
Below you will find information about Order Capital. We are hiring and would be happy to discuss opportunities for professional growth with you.
Based in Dubai
We’re a place where:
We’re looking for:
We loved working on this round and hope it’s fun for you. If you’re curious about what we do at Order Capital — we’d love to hear from you! Just fill out a quick form.
This is our debut contest — and we’ve worked hard to make it fun, fair, and memorable. We hope you’ll enjoy the experience!
GL & HF!
