Hello codeforces!

I'm glad to announce that codeforces round #478 for the second division will take place on Tuesday, May 1st 17:05 MSK. First division participants can also take part out of competition.

Great thanks to Nikolay Kalinin (KAN) and Fudail Hasan (fudail225) for helping me prepare the contest, to Mike Mirzayanov (MikeMirzayanov) for the great Codeforces and Polygon platform, Many thanks for Amr Mahmoud (RetiredAmrMahmoud ) Tameem Zabalawi (timo14z), AmirReza PoorAkhavan (Arpa), Alexey Ilyukhov (Livace), Hag Ahmad (Reckt), Nikita Bosov (FalseMirror) and Andrew Rayskiy (GreenGrape) for testing the round.

You will be given five problems and two hours to solve them. The scoring distribution will be published soon. Good luck everyone!

I hope you'll enjoy my round. I wish everyone good luck and high rating!

UPD1: problem scores: 500 — 1000 — 1500 — 2000 — 2500

UPD2:

Congratulations to the winners

1- kmjp

2- TangentDay

3- Llamap.

4- E869120

5- kevinsogo

Div.2 winners:

1- Llamap.

2- amarDhcuMoS

3- phongthan

4- Nirma_Sucks

5- MagolorSoul

UPD3 : Tutorial is out!.

Hello Codeforces!

On April 30, 17:35 MSK Educational Codeforces Round 43 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 Div. 2. It will be held on extented ACM ICPC rules. After the end of the contest you will have one day to hack any solution you want. You will have access to copy any solution and test it locally.

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

The problems were prepared by Mikhail awoo Piklyaev, Roman Roms Glazov, Adilbek adedalic Dalabaev and me.

We'd like to thank Ivan BledDest Androsov and Maksim Neon Mescheryakov for the help in preparing the round.

Good luck to all participants!

UPD: The round will contain 6 problems instead of 7.

UPD2: Editorial

Congratulations to the winners:

Congratulations to the best hackers:

777 successful hacks and 656 unsuccessful hacks were made in total!

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

Hi everyone!

Tomorrow, on the April 29, 2018, at 13:05 UTC we are holding the third round of VK Cup 2018 championship. This is the final online round, the next round is the final round in which top 20 teams from this round advance.

At the same time with the official round, we are holding parallel rounds for both divisions. Join them and see if you can beat top Russian-speaking teams! Top50 in the "Div1 Edition" contest will get t-shirts.

All rounds are rated, their duration is 2.5 hours.

The authors of the problems are Zlobober, Endagorion and me. Thanks qwerty787788 and vintage_Vlad_Makeev for their great help in round preparation!

Good luck!

Congratulations to winners!

1. V--o_o--V, LHiC — solved all problems, two problems ahead the runner-up!
2. craborac, demon1999
3. el_sanchez, SpyCheese
4. Melnik, hloya_ygrt
5. egor_bb, Nikitosh

Mirror for the first division:

1. fateice
2. Petr
3. tourist
4. budalnik
5. TLE

Mirror for the second division:

1. _ChenKerui
2. Hayven
3. poisonous
4. Gold_Three_Fat
5. laofudage

The editorial is here, thanks all for participation!

Hello!

This blog post is about the end of the crowdfunding campaign dedicated to the 8th anniversary of Codeforces. Everything worked out. Hooray!

For us, it is very important to support not only in terms of the collected budget, but as a powerful indicator that Codeforces is important to you. It was very pleasant to read words of gratitude and congratulations. Thank you!

We received more than 1000 donations from community members from around the world. For 45 days we've collected more than $60000 dollars. The collected funds will allow us to continue to move forward, to please you with new contests and improvements of the system.

I am happy to report that starting in May 2018, we will be able to slightly increase rewards for problem writers.

We tie the money paid in rubles to the Central Bank of Russia exchange rate, rounded to the closest sum in rubles divisible by 5 (according to the rules of mathematical rounding). The table shows the values that were up-to-date when this post was published. An asterisk marks the bonus that is given if the round is prepared in time and without major issues in problems.

In addition, the collected funds will help to increase a reward of the problem coordinators KAN and [user:gritikan]! Guys, you're doing a very important job, thank you for that!

Improvement of Codeforces hardware has already been launched, which will help improve the stability of the system and keep up with the growth of the audience.

To all those of you who are expecting a gift from us (certificate, T-shirt, hoodie), I remind that it is necessary to fill in or update the information in the profile about the delivery address. Please do not delay this!

Thank you again for your support!

MikeMirzayanov

Hi everyone!

Tomorrow, on the April 25-th, 2018 at 17:35 UTC we are holding Codeforces Round 476 (Div. 2) [Thanks, Telegram!]! The round will be rated for the second division participants, members with higher rating can take part out of competition.

I give the floor to MikeMirzayanov to announce the round:

This round opens a series of thanks-rounds to those who significantly supported Codeforces in the crowdfunding campaign for the 8th anniversary. Although Telegram is not explicitly present on the list of donators, for us this is the first and most important friend. We express our gratitude to Telegram and personally to Pavel Durov for the constant support and send regards from programming contest community. Now that the medieval inquisition against Telegram and all the free Internet has been declared in our country, I admire and express support for Pavel's principled position on protecting our rights and freedoms. Thank you, Telegram!

I join the thanks to Telegram, and also want to thank FalseMirror and Livace who helped me with the problems for the round. Also many thanks to vintage_Vlad_Makeev, GreenGrape and 300iq for their help in round preparation, and arsor for translation.

Good luck!

Congratulations to winners!

Div. 2:

1. Akylbeek — solved all problems!
2. kolkulator
3. reeWorld
4. 16bit075
5. teamskiy

Div. 1:

1. uwi
2. quailty
3. bicsi
4. Barichek
5. Adalbert

The analysis is here.

Hello everyone!

acm.sgu.ru was created ~16 years ago by programming contests participants from Saratov university: MikeMirzayanov and AndrewLazarev. Today its codebase and infrastructure are completely outdated, and supporting it is unreasonably hard. Nonetheless, Codeforces team is regularly asked to revive acmsguru, since there is still a lot of interest in the problemset.

Here is the new functionality in Codeforces — additional section "acmsguru" in Problemset. All the problems from the old system are moved there. There are still a few things to do here: correctly port interactive problems, improve looks of statements, support the new section in Codeforces API, support adding these problems to mashups.

Anyway, you can solve the problems already, and view progress on separate standings page for acmsguru.

To save the spirit of acmsguru, viewing sources of other participants is disabled.

UPD: In some old problems checkers are compiled into 16-bit executables, so testing of these problems is temporarily not working.

April 19, 15:35 (UTC) the VK Cup 2018 - Wild-card Round 2 will start.

Participants are invited to achieve progress in solving an unusual problem. VK Cup teams which were advanced to the Round 2 (and didn't advance to the Round 3) will take part in VK Cup 2018 - Wild-card Round 2 officially. In addition, this round will be open to the public for unofficial participation for everybody. Registration will be open for the whole round duration.

The round will be one week long. After the end latest submission (with positive score) of each participant will be judged on system tests.

Good luck!

ACM-ICPC World Finals 2018 will begin on April 19, 2018 at 2:00 (UTC). This event is the main event of the year in the world of sports programming!

In the past 20 years alone, ICPC participation has increased by more than 2000%. Last year, ICPC Regional participation included 49,935 of the finest students and faculty in computing disciplines from 3,098 universities in 111 countries on six continents. A record 53,446 students and 5,411 coaches competed in ICPC and ICPC-assisted competitions last year, setting new records in participation.

Codeforces wishes the teams to show a vivid and interesting contest. We wish to find beautiful solutions, write without bugs and enjoy many accepted problems!

Links:

• Current results
• Official website of the championship
• ICPC News (photo, video about the Finals)
• ICPC Live (broadcast and not only)

More than 300,000 students competed worldwide in local and regional events with one aim — to participate in World Finals, this year hosted by Peking University in China. And today we will see who will become the world champion!

A total of 140 teams of three students will face about 12 difficult problems (we don't know the number until the problem set is released!). They will have 5 hours to solve the problems.

Although the contest itself takes 5 hours only, the whole event takes 5 days. So, what is going on during these days?

Through the registration evening, each team was given different color shirt and their badges, as well as other goodies like a backpack and a cute stuffed panda bear. We took photos and videos of each team so we can share about them on various social media.

Monday began with JetBrains TechTrek Presentation and a really fun sponsor showcase with games and activities. Contestants could participate in many things — they could try writing Chinese characters, playing traditional Chinese games or instruments, try sports in VR and more... The day was ended with a stunning concert of both traditional and contemporary Chinese music from Peking University, including some original compositions.

On Tuesday we were amazed by The Giant Wall of China. That day we become true men because the Chinese saying is that one is not fully human until he climbs the Great Wall. It was surprisingly steep. Hundreds of people from 6 continents climbed it and had amazing views of the mountains.

The afternoon was all about the opening ceremony, which had speeches, awards for many wonderful people and a presentation of all the teams, interlaced with cultural performances.

Wednesday was an important dress rehearsal. The program is similar to the competition day. It lets everyone find issues so the finals on Thursday can run as smoothly as possible. There are always some technical issues, problems with logging in, printers, etc., but they all got worked out. In the afternoon, contestants had a rest, enjoy a sponsors' ChillZone with games and do the last preparations for the tomorrow's contest.

140 teams participate in world finals. But there are many other people standing behind scenes — coaches, organizers, judges, ICPC teams (News, Services,...) and many other volunteers, totalling in about 1000 people!

The ACM ICPC world finals aren't only about competing. It is also about meeting with great programmers from all around the world, encountering other cultures and sharing the joy of programming. For me, this event is truly awesome and fun to be part of!