Hello everyone!

Good news — Russian AI Cup 2018 has started! This competition is being held seventh time, and this time we hav a sport game in football/Rocket League style. Task is simple — score more goals than your opponent!

Try yourself in creating an artificial intelligence, it's simple and fun. Go to Russian AI Cup site and enter the battle. Good luck!

This time we also allow you to try the game out by playing it it the browser

Hi all!

This weekend, at Dec/23/2018 16:35 (Moscow time) we will hold Codeforces Round 528. It is based on problems of Technocup 2019 Elimination Round 4 that will be held at the same time.

Technocup is a major olympiad for Russian-speaking high-school students, so if you fall into this category, please register at Technocup 2019 website and take part in the Elimination Round.

Div. 1 and Div.2 editions are open and rated for everyone. Register and enjoy the contests!

The round was prepared by Roms, Neon, BledDest, adedalic, awoo, isaf27, Endagorion with coordinator's help from 300iq.

Have fun!

Hello.

On December 23rd at 07:00 UTC we are hosting the second elimination round of our olympiad for high school students. More information on olympiad's website. The rules are IOI-like. Round will last for 5 hours, and consist of 5 problems to solve.

Live standings

We hosted the first round Innopolis Open, First elimination round, 2018-2019 on December 1st. Those, who already advanced to the final round, can skip the round, but certainly can participate if they want.

We can discuss problems after the round here.

Good luck all!

I'm in the middle of the session but I'm still trying to prepare Div. 3 rounds.

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Hello!

Codeforces Round 527 (Div. 3) will start at Dec/18/2018 17:35 (Moscow time). You will be offered 6 or 7 problems with expected difficulties to compose an interesting competition for participants with ratings up to 1600. Probably, participants from the first division will not be at all interested by this problems. And for 1600-1899 the problems will be too easy. However, all of you who wish to take part and have rating 1600 or higher, can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ACM-ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks. I tried to make strong tests — just like you will be upset if many solutions fail after the contest is over.

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

Note that the penalty for the wrong submission in this round (and the following Div. 3 rounds) 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 participants of the third division, you must:

• take part in at least two 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.

Thanks to MikeMirzayanov for the platform, help with ideas for problems and for coordination of my work. Thanks to my good friends Mikhail awoo Piklyaev, Maksim Neon Mescheryakov and Ivan BledDest Androsov for help in round preparation and testing the round.

Good luck!

I also would like to say that participants who will submit wrong solutions on purpose and hack them afterwards (example) will not be shown in the hacking leaders table.

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UPD: I also would like to thank Roman Roms Glazov, Farkhod Farhod Khakimiyon and Alex hohomu Poon for help with testing the round.

UPD2:

Congratulations to the winners:

Congratulations to the best hackers:

796 successful hacks and 2063 unsuccessful hacks were made in total!

And finally people who were the first to solve each problem:

UPD3: Editorial is published!

Hi!

I'm glad to invite you to participate in Avito Cool Challenge 2018 which starts on Dec/16/2018 17:35 (Moscow time). The round will be rated to participants of both divisons.

The problem setters are TLE, sunset, fateice, yanQval and quailty.

We would like to thank:

• cdkrot and 300iq for coordinating and helping us with the round.
• Lewin, Ashishgup, winger, AlexFetisov, vintage_Vlad_Makeev and isaf27 for testing the round and giving advice.
• choutii for playing a crucial role in the contest. (you'll see.)
• MikeMirzayanov for awesome Codeforces and Polygon.
• Avito for generously sponsoring this round.

This round is conducted on the initiative and support of Avito. Avito.ru is a Russian classified advertisements website with sections devoted to general good for sale, jobs, real estate, personals, cars for sale, and services. Avito.ru is the most popular classifieds site in Russia and is the third biggest classifieds site in the world after Craigslist and the Chinese website 58.com.

Avito presents nice gifts for participants. Top 30 participants and also 10 random participants with places 31-130 will be awarded with a special T-shirt.

You will be given 8 problems and 2.5 hours to solve them. As usual, the score distribution will be revealed shortly before the contest.

This is the first contest on Codeforces for most of us. Hope to see you participating! Good luck!

There will be an interactive problem in the round. If you have never solved interactive problems before, please read this.

UPD: The scoring distribution is standard 500-1000-1500-2000-2500-3000-3500-4000.

UPD: Congratulations to winners!

• tourist
• LHiC
• xyz111
• mnbvmar
• V--o_o--V

Also, you can find the list of T-shirt receivers here.

UPD: Editorial

Hello Codeforces!

On Dec/15/2018 17:35 (Moscow time) Educational Codeforces Round 56 (Rated for Div. 2) will start.

Series of Educational Rounds continue being held as Harbour.Space University initiative! You can read the details about the cooperation between Harbour.Space University and Codeforces in the blog post.

This round will be rated for the participants with rating lower than 2100. It will be held on extented ACM 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 7 problems and 2 hours to solve them.

The problems were invented and prepared by Roman Roms Glazov, Adilbek adedalic Dalabaev, Vladimir vovuh Petrov, Ivan BledDest Androsov and me.

Good luck to all participants!

Our friends at Harbour.Space also have a message for you:

Hello Codeforces!

We are excited to announce that the Hello Muscat Programming Bootcamp registration is open! The camp will take place from March 9th to March 15th, 2019, and our early bird discount of 15% is going until December 15th!

This next edition in our Hello Programming Bootcamp will run in parallel with the traditional Moscow ICPC Workshop — both Bootcamps’ contests will be identical, and contestants will be able to see their position in the General Leaderboard. Every day, both camps will be competing simultaneously, 4,000 kilometers from each other!

Congratulations to the winners:

Congratulations to the best hackers:

And finally people who were the first to solve each problem:

UPD: Editorial is out

Hi!

I'm glad to invite you to Codeforces Round #526, which will be held on Dec/10/2018 19:35 (Moscow time). The round will be rated for both divisions.

Problems were prepared by me, TheWayISteppedOutTheCar, xoxo, kiyotaka.

Thanks to ismagilov.code, Kuyan, 300iq, alexey_kuldoshin, Jatana for testing, arsijo and vintage_Vlad_Makeev for helping us and MikeMirzayanov for the great Codeforces and Polygon platforms.

You will be given 6 problems in each division and 2 hours to solve them.

UPD:

The scoring distribution in Div. 1: 500-1000-1500-2000-2000-2500

The scoring distribution in Div. 2: 500-1000-1500-1750-2250-2750

UPD: Congratulations to winners!

Div. 1:

1. Radewoosh

2. DearMargaret

3. Endagorion

4. ksun48

5. Um_nik

Div. 2:

1. Muffinhead

2. Usu

3. arjunsanjeev7

4. IAmNotGood

5. tyler

UPD: Editorial

Hello friends!

This weekend, on 8-9th of December — St. Petersburg, Barnaul, Kremenchug, Tbilisi, Almaty and Sochi will host the XIX Russia Team Open High School Programming Contest. Competition will be attended by more than 250 teams. Contest is held for the first time in Sochi this year -Educational Center “Sirius” will host nine teams.

The main contest will start on 9th of December at 10:00. You can follow current results by the link. Link to the tasks will be able right after the start of the tour.

A mirror will be available on Dec/09/2018 11:05 (Moscow time) – this is for those, who are not a participant, but also want to solve interesting problems! Do not join our broadcasts if you plan to take a part in the mirror. We warn you that, because of spoilers. And, of course, do not open the problem conditions before the start of the round.

If you do not want to participate in a mirror, be sure to join our broadcasts — in video format from the ICPCLive team and in text format in our Telegram-channel!

And if you want to come to the Russia Team High School Contest in St. Petersburg as a guest – just fill in the guest form and get your badge at the registration!

Our friend ismagilov.code has a post – follow this link to see a large set of commands with their total rating. Thank you for interesting information!

And please welcome some teams that stand a good chance to become Cup winners:

Greetings!

Ugh! That guy comes with another online-mirror and ruins my timeline again.

Here is the last one this year I could share with you, 2018-2019 ACM-ICPC, Asia Jiaozuo Regional Contest. It will start on Saturday, December 8, 2018 at 17:00 (UTC+8) and last for 5 hours. You are able to register 6 hours before the contest starts. However, before the registration starts, you may not view this contest on Gym. By the way, other Asia east continent regional contests shared by my friends and I could be found at Nanjing, Shenyang, Qingdao, Beijing and Xuzhou.

This onsite contest was held by Henan Polytechnic University on November 25th. It is the first time one regional contest was held on HPU, but it is quite memorable. Among the above 6 regional contest, I could definitely say Jiaozuo is the second easiest one. Though it may contain a few hard problems, several problems are solvable for beginners.

The problems are prepared by AHdoc, Claris, quailty and me. Thanks to zscc for discussing ideas, yefllower and niike0goood for testing, and MikeMirzayanov for developing wonderful platforms and kindly answering technical issues.

There is one thing we need to point out again. For everybody who has already read the problems, please do not to participate in this online-mirror contest or discuss solutions before the contest has ended. We have shared solution sketches (in simplified Chinese) in this site, so if needed, we would share some hints (in English) after online-mirror.

At the end of my post, I sincerely recommend authors of Asia-Hongkong (was held on Nov. 18) and Asia-East Continent Final (will be held on Dec. 16) would share problems with the public at any website. Your efforts should be rewarded!

UPD1: As a kindly reminder, our sponsor Jisuanke will hold another online-mirror contest soon after the contest on Gym, which will start on Sunday, December 9, 2018 at 12:00 (UTC+8) without the onsite board.

UPD2: Contest will start 1 hour in advance, as there is a CodeChef SnackDown contest soon after.

UPD3: Registration starts. You may view this page to register.

UPD4: Hints for this contest are published.