Hi!

On April 23, 19:35 MSK will be held rated Tinkoff Challenge – Elimination Round.

Problems were prepared by me — Ildar Gainullin, Alexander wrg0ababd Kurilkin and Nikolay KAN Kalinin.

Big thanks to Vladislav winger Isenbaev and Alexander AlexFetisov Fetisov for testing round, and also to Mike MikeMirzayanov Mirzayanov for systems Codeforces and Polygon.

Participants will be offered seven problems and two hours to solve them. Scoring will be announced a bit later.

This round is eliminational for Tinkoff Challenge.

Best 30 participants will be awarded with warm vests and other pleasant souvenirs like stickers and notepads. Best 100 participants will be invited to Moscow to visit Tinkoff's office with panoramic view on the city.

Best 20 participant who will be able to arrive will advance to Tinkoff Challange – Final Round.

We hope everyone will find interesting problem for themselves. We wish everyone a successful round and high ratings!

UPD. Scoring: 500 1000 1500 2000 2500 3000 3500

UPD. Editorial

Hi everyone!

I'm pleased to announce Codeforces Round #410 (Div. 2) that will take place on Friday, 17:35 MSK. I'm the writer of the round.

I'd like to say thanks to Alex netman Vistyazh and Marcel please_delete_account Bezdrighin for feedback and help in preparing the round and to MikeMirzayanov for awesome platforms : Codeforces and Polygon.

I hope you will like the problems.

Good luck and have fun!

UPD: Scoring distribution: 500 — 1000 — 1500 — 2000 — 2500

UPD 2. The round is finished. Congratulations to winners:

Div 2:

1. Gonens

2. Blue_Sky.

3. kimnoia

4. Guy

5. jtnydv25

Div 1:

1. OnionPringles

2. unused

3. uwi

4. Reyna

5. alexrcoleman

Editorial: Link

Hello!

The round 2 of VK Cup 2017 will take place on April 16 at 18:35 MSK (check your timezone here), along with separate div1 and div2 Codeforces Round #409. The contest "VK Cup 2017 — Round 2" is for teams qualified from round 1. The top 100 teams will advance to the Round 3, while other ones will have one more chance in the Wild Card Round 2 later this month. Those who don't participate in the VK Cup can take part in the Codeforces Round #409 individually (problems will be available in English too). All three rounds last 2 hours, and all are rated.

The round would not be possible without the following people (in no particular order): KAN, Errichto, winger, AlexFetisov, LiChenKoh, xiaowuc1, MikeMirzayanov. Additionally, I thank VK company for sponsoring this contest.

As usual, the scoring distribution will be announced later.

UPD 1: The scoring distribution is as follows:

div2: 500 — 1000 — 1500 — 2000 — 2750

div1 and official round: 500 — 1000 — 1750 — 2250 — 2250

UPD 2: The tutorial is available here: http://codeforces.com/blog/entry/51598

Congratulations for the winners

Official round:

1. LHiC, V--o_o--V
2. I_love_Tanya_Romanova, enot110
3. netman, andrew.volchek
4. aid, ershov.stanislav
5. MrDindows, Rubanenko

div 1:

1. SirShokoladina
2. jqdai0815
3. jcvb
4. Syloviaely
5. Um_nik

div 2:

1. ngkan
2. justarandomstring
3. fgvfgfg1
4. DryukAlex
5. DorMOUSENone

Hello everyone!

Top 200 from the First Qualification Round have already advanced to the Elimination Round, but the other paricipants still strive to get there. If you haven't qualified yet, we invite you to take part in the Second Qualification Round that will take place this Sunday, April 16, at 12-00 Moscow Time. Best 200 participants will advance to the Elimination Round, other participants can try again in the Third Qualification Round.

Good luck to everyone, see you at http://russiancodecup.ru!

Hello Codeforces!

On April 15, 17:35 MSK will be held Educational Codeforces Round 19.

This Educational Round is held as Harbour.Space university initiative. It's the second round supported by Harbour.Space. You can read the details about the cooperation between Harbour.Space and Codeforces in the blog post.

Some educational programs in Harbour.Space are interesting for most Codeforces users. One of them is Data Science Program. Here is few words from Sergey Nikolenko, Harbour.Space lecturer and Senior Researcher, Steklov Institute of Mathematics at St. Petersburg Russia.

The round will be unrated for all users and it will be held with extented ACM ICPC rules. After that 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. We tried to prepare such problems that both novices and experienced coders will find something interesting in this contest.

The round was prepared by Ivan BledDest Androsov, Mikhail MikeMirzayanov Mirzayanov and me.

Wish you enjoy the contest! Good luck!

UPD: Editorial

Congratulations to the winners:

Congratulations to the best hackers:

234 successful hacks and 308 unsuccessful hacks were made in total!

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

Hello Codeforces!

HFT Battle 2017 is going on – the trading algorithms competition, in which every participant can try on an HFT researcher’s hat. The goal is to create a stable and profitable HFT algorithm by researching a market microstructure and a behaviour of the financial instrument. In May we will be hosting another 24-hour competition in code optimization and speeding up based on algorithms created during HFT Battle. We hope that Codeforces users will especially like this format :)

During the competition we provide you a set of real HFT-instruments for research and strategy analysis and real market data from one of the world’s largest exchanges. Same as last year, trading conditions are simplified compared to the real ones: there are lower fees and round-trip.

Also there are some significant differences from the previous competition:

• You are able to create your strategies both in C++ or Python.
• We made it possible to participate in teams. To do this you should create a single account for the entire team and provide the information about one of the participants during the registration process.
• You can call out any other participant for a duel, where your strategies can see and affect each other’s transactions. Let the battle begin!

How to start

To make the strategy development easier, we have prepared the sample strategy and collected few ideas for the algorithm improvement at one place with the corresponding code examples.

We suggest you to start with the brief documentation, which will be enough for you to become familiar with the competition system. Also we have developed the offline development package: https://github.com/hftbattle/hftbattle.

The competition ends on the 30th of April 2017. The final testing will be held after that on a set of 20 new trading sessions.

This year TOP-20 participants will be awarded with valuable prizes. The best competitors will be invited to an interview at AIM Tech and will have an opportunity to join our team.

We will be happy to hear your feedback! You may use “Support” button in the web interface or text directly to [email protected]. You may also join the active discussion of the contest in our Telegram channel!

It is not required to have any specific economical knowledge to create your strategy. Basic C++ or Python skills would be enough. We are confident that most of Codeforces participants will be able to reach excellent results!

We wish you high rating and great results in HFT Battle 2017!

Hello, Codeforces!

It is time to tell about the improvements in Polygon. It is a system for the preparation of programming problems. All Codeforces rounds and many other olympiads prepared in Polygon. Everyone at any time can use this system.

Common

A special fields with examples now displayed on a page with a list of files which used in problem and on checker, interactor and validator pages. It will be very useful for the new users and will help them faster understand the system.

NAIPC is coming up on April 15 (start time here). More information can be found on the site. The contest will be on Kattis on the 15th. About 15 hours later, it will be available as an open cup round as the Grand Prix of America. Please only participate in one of them, and don't discuss problems here until after the open cup round.

The deadline to register for the contest on Kattis is April 12th. You can register by following instructions on this site: http://naipc.uchicago.edu/2017/registration.html# You will need an ICPC account to register.

You can see previous NAIPC rounds here: 2015, 2016. 2016 is also available in the codeforces gym here: http://codeforces.com/gym/101002

UPD 1: The deadline to register is in a couple of days.

UPD 2: Both contests are now over

NAIPC standings: https://naipc17.kattis.com/standings

Open Cup standings: http://opentrains.snarknews.info/~ejudge/res/res10376

I'll update this one more time with solutions once they are up.

UPD 3: Test data is available here (solutions may show up later, but I'm not sure when): http://serjudging.vanb.org/?p=1050