Hi Codeforces!

We strike back from last year to held Bubble Cup again — programming competition organized by Microsoft Development Center Serbia for last nine years in a row. And this year's final is on this weekend!

Due to last year's successful experience we decided to organize a mirror of this final on Codeforces again. We would like to thank MikeMirzayanov and Codeforces for this great platform and their help. Competition will start at 11-th of September at 11 AM 12:00 (Moscow time). Contest will last for 5 hours and will go by ACM ICPC rules. It will be a competition for teams of 1-3 members. There will be 9 problems.

Contest was mainly prepared by employees of MDCS, knightL and Milanin. Additional thanks to bayleef and vitar for their help in testing.

This contest will be unrated (mostly because rules of this contest and not usual for Codeforces and it is still a mirror of onsite competition).

10 best teams will get T-shirts (each member get one), +10 T-shirts will be distributed randomly to competitors from top 100.

Please pay attention to that contest will start at 12:00 (by Moscow time)

Hi everyone. I'm trashfirstsearch, and I used to be blue...

Anyways, Codeforces Round #370 (Div. 2) will take place on 10 September 2016 at 19:35 MSK. As usual, Div.1 participants can join out of competition.

Much thanks to GlebsHP for helping me with preparing the contest, MikeMirzayanov for the Codeforces and Polygon platforms, and minimario and Wrong_Answer_Exceeded for testing problems.

This will be my first contest prepared on Codeforces, and I have prepared all the problems with the intent of making them interesting for everyone. It is, as usual, strongly advised to read all the problems.

Good luck, and I hope you will gain rating(and force someone else to lose it >:) ).

Update: Congratulations to the winners:

Div.1

1. KrK

2. halyavin

3. fhlasek

4. vintage_Vlad_Makeev

5. Kmcode

Div.2

1. __0v0__

2. palayutm

3. Strikeskids

4. khanh.tang

5. pkq2010

Here is the editorial.

I sincerely apologize for the problems during the contest. However, I hope everyone found the problems interesting! Thanks to everyone who participated and helped with the problems!

Welcome to 2016-2017 CT S03E01: Codeforces Trainings Season 3 Episode 1 - 2010 Benelux Algorithm Programming Contest (BAPC 10). The training duration is 4.30 hours. It is opened for teams as well as for individual participants. After the end you may use the practice mode to complete problem solving. Also it will be availible as a virtual contest for whose of you who can't take part today. Please, do not cheat. Only fair play!

It is possible that the problems will be too easy for some participants, it is possible that we will add some problems.

Good luck!

The new season of a collegiate team championship ACM-ICPC is about to start. For example, the registration for the Southern (Saratov) Subregional Contest is already running. I am sure that many participants of the Codeforces rounds will take part in ACM-ICPC this year.

We are launching a series of weekly practice trainings on Codeforces. Naturally, they will be held within Codeforces::Gym. Feel free to participate!

The practice starts on Wednesdays at about 13:10 PM (UTC), which is 16:10 Moscow Time. Expected duration is 4-5 hours. We are going to practice using the problems of different contests of the past years. All you need is common sense and observing these simple rules:

• We will not publish the problem source before the practice starts. We want you to solve the problems on your own in a fair competition. If you use somebody else’s code or cheat in any other way, you will be disqualified. If you don’t want to solve on your own, that’s fine, you don’t have to. But spoiling the practice for others is unacceptable.
• Do not discuss the problems till the practice ends.
• We will rarely answer the questions about problems. If you’ve found some obvious bug, please let me know. We will fix the bug and send everybody the note about the fix.
• If you have a coach account (and you do not participate in the practice), we will be grateful for your help.
• Please register for the practice with the people from your team who actually participates in it.
• From time to time, I am going to ask some of the jury of the past contests or coaches from other higher educational institutions to help with preparing or share materials — your understanding and help will be greatly appreciated!
• if you solved the contest problems before just switch to another training or inform us via problem questions form, we will move you to out-of-competition role.

The first contest 2016-2017 CT S03E01: Codeforces Trainings Season 3 Episode 1 - 2010 Benelux Algorithm Programming Contest (BAPC 10) takes place on September, 7, at about 13:10 (UTC).

From 8 to 18 November 2016 the Moscow International Workshop ACM ICPC is going to be held at Moscow Institute of Physics and Technology.

Moscow International Workshop ACM ICPC presents programming education and training camp for students. It is traditionally held by the Moscow Institute of Physics and Technology and the University ITMO with the Lomonosov Moscow State University and this year is going to be the sixth time the event is taking place. The workshop is aimed at training and educating students in programming for successful participation in the ACM ICPC. The official language is English.

The workshop schedule is planned to have 9 workdays that include daily contests and problem analyses, as well as lectures and time for upsolving. In the evenings, there will be sports and other activities.

Contests are moderated by Oleg Khristenko: coordinator of the Pankratiev Open Cup and the main editor of Snarknews.info

The training is going to be held in accordance with the "one and a half divisions" scheme. No less than four and no more than five rounds out of nine will be non-thematic five hour long contests with the same level of difficulty as those of the ACM ICPC Regionals. The overall standings will be formed by the results of these rounds. The remaining rounds will be held separately by divisions. The Division A (for experienced teams' training) will also have non-thematic five hour long contests of the ACM ICPC Regionals difficulty level; analyses of non-thematic rounds will be held by MIPT team trainers. The Division B (educational) will have two thematic shortened contests in the morning and in the evening, as well as a lecture in the corresponding topic and analyses of problems composed by lecturers. The schedule is composed in the way that makes it possible for participants of the Division A to submit an application to the organizing committee to become lecturers (on the same conditions as invited lecturers). Teams select a division to participate in themselves. Aside from the overall standings, each division will have its own separate standings calculated, so winners of each division will also be rewarded.

The organizing fee is 34.000 rubles for citizens of countries of the Eurasian Economic Union and $640 for everybody else. This cost includes the curriculum, meals and accomodation in the MIPT campus, as well as the sports and travel programme for weekends. We are also ready to aid with Visas.

Participants and teams that are willing to take part in the training need to pass the preliminary registration. Registration extended until October 24, however if you need a visa in order to enter Russia, we urge you to register until October 12. Information for coaches: if you intend to send a team to the training but will not be sure which one until October 12, and in turn cannot pass the registration, please send us an application with specification of the number of participants to our email [email protected]

Our website: http://it-edu.mipt.ru/en/fall_training_2016

Our email: [email protected]

On Saturday, September 3rd TopCoder Open comes to Saint-Petersburg. Russia! Event highlights include:

• an onsite round of Algorithm Competition: an SRM-style competition with top-10 participants advancing to the online Wild Card Round, from which two winners go to TCO finals in Washington DC (rules).
• T-shirts for all attendees :-)
• if during the next week (till July 22nd) by August 19th the event gathers 100 participants, TopCoder will add a lightning Marathon match with the same rules as for NYC regional event — the Marathon itself takes place before the onsite and is open for everybody to attend, and at the onsite closing ceremony the winners are celebrated. At the moment there are 26 60 94 registrants.

If you want to participate, register, and the sooner the better :-)

Upd. List of registrants

I am glad to inform you that C++14 has been added to the list of supported languages ​​on Codeforces. The choice fell on the compiler MinGW-w64, version of GCC 6.2.0 (will be updated on new releases). If you have Windows, you can easlily install it using PBOX with one command pbox install mingw-w64.

Besides trendy features of C++14 (not sure there's a lot to the contests), there are some advantages:

• this compiler is faster than mingw-tdm 5.1.0 on cin/cout — for example, reverse a sequence of 10⁶ integers from 1 to 10⁶ runs 1.5 seconds instead of 2.5 (0.3 vs. 1 if you use std :: ios :: sync_with_stdio (false))
• works correctly to print a double with the both specifiers %f and %lf (you should read using %lf)
• works correctly to read-write long double with the specifier %Lf
• works correctly to read-write long long both with %lld and %I64d

It seems that lately we remove support of MinGW C++/C++11 (especially since it is difficult to upgrade them to GCC 6 due to backward compatibility issues). Of course, after a while C++14 will appear on Polygon.

Important Update: Our friends have noticed that the upcoming round collides with their contest and also weekend is full of many another contests, so the round is now moved to Monday, 29 August 2016 15:05 MSK. We are sorry for the inconvenience caused and hope that you'll understand us.

Hi everyone!

Codeforces Round #369 (Div. 2) will take place on 27 August 2016 at 16:05 MSK. As usual, Div.1 participants can join out of competition.

I would like to thank danilka.pro for helping me with the preparation of the round, MikeMirzayanov for the amazing Codeforces and Polygon platforms and also Phyto for testing the problems.

I am the author of all the problems, and danilka.pro also helped making one of the problems harder. This is my first round on Codeforces! Hope everyone will enjoy the problems and find them interesting. It is advisable to read all the problems ;)

In this round, you will help ZS the Coder and Chris the Baboon while they are on an adventure in Udayland. Can you help them solve their problems? :)

Good luck, have fun, and wish everyone many Accepted Solutions. :)

UPD : Also thanks to IlyaLos and HellKitsune for testing the problems too.

UPD 2 : There will be 5 problems and the scoring is standard : 500-1000-1500-2000-2500.

UPD 3 : Editorial

UPD 4 :

Congratulations to the winners :

Div. 1 winners :

1. matthew99

2. uwi

3. Egor

4. Um_nik

5. kmjp

Div. 2 Winners :

1. zhabo

2. ysy_ioi_pengbei

3. YangJunzhao

4. lych_cys

5. Zharaskhan

Hi, Codeforces!

AIM Tech Codeforces Round 3 will take place on August 24, at 19:35 MSK.

The round is prepared by AIM Tech employees: Kostroma, riadwaw, yarrr, ValenKof, Edvard, bobrdobr, malcolm, NVAL, nmakeenkov, agul, Extr and zeliboba. Round will take place during Petrozavodsk Summer Camp, which is sponsored by our company.

We made our problems a little easier than at AIM Tech Round 1 and AIM Tech Round 2 but we promise they won’t be less interesting. Scoring system will be static.

Thanks to Mike Mirzayanov(MikeMirzayanov) for brilliant platforms Polygon and Codeforces and problem coordinator Gleb Evstropov (GlebsHP). Many thanks to AlexFetisov and winger for round testing!

Our company specialises in proprietary trading, the key concepts in our work are big data, low latency and high frequency. Our team mainly consists of graduates from the MSU Faculty of Mechanics and Mathematics and Moscow Institute of Physics and Technology (MIPT).

We wish you good luck and high frequency rating!

Scoring in both divisions 500-1000-1500-2000-2500

Editorial