Hello, Codeforces!

My name is Ivan Udovin, and I would like to say, that the Codeforces Round #344 will be held on Thursday (March 3, 2016 at 19:35). This is our first round, but it doesn’t mean that problems will be boring and not interesting. The problemsetters of this round are me (wilcot) and Ilya Kheifets (xfce8888). Thanks a lot to Alex Vistyazh (netman) and unknown person (he don’t want to be added in the announcement) for testing our round. Also I’d like to thank Fedor Korobeynikov (Mediocrity) for his awesome idea for task E.

We thank Gleb Evstropov (GlebsHP) for his help in preparing the contest, Maria Belova (Delinur) for translating the statements into English, and, of course, Codeforces team and Mike Mirzayanov for unique Codeforces and Polygon platforms.

This round consists of five problems. Main heroes of this round: Blake — the owner of the "Blake Technologies" company, and Chris — an employee of this company, and others.

Scoring distribution: 500, 1000, 1500, 2000, 2500.

Good luck, have fun.

PS. Editorial is ready.

PPS. Congratulations to the winners:

Div. 2:

1. lovelive

2. Murtazo.Ali

3. chychmek

4. chrome

5. Batman

Div. 1:

1. Um_nik

2. chffy

3. natsugiri

4. ershov.stanislav

5. AndreiNet

Hello, Codeforces!

Today is the first day of the spring and it's great!

Educational Codeforces Round 9 will take place on 01 march 2016 at 18:00 MSK for the first and the second divisions. You can read about educational rounds here and here. I should again notice the high density of contests and championships.

<This time it wasn't changed>

The round will be unrated for all users and it will be held with extented ACM ICPC rules. You will have two hours to solve six problems. 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.

If you have ideas for some problems or maybe already prepared problems that you can't use in rounds or official competitions, you can write to me.

It seems that it is harder to invent interesting simple problems (like A and B) than difficult ones. So don't be afraid to suggest interesting simple or very simple tasks.

</This time it wasn't changed>

The problemset again was totally suggested by Codeforces users. The problem А again was suggested by user unprost (be ready to see a long problem statement). The problem D suggested by Denis Bezrukov pitfall. Alexey Chesnokov CleRIC sent the problem E a long ago. The problems B, C and F was suggested by Lewin Gan Lewin.

Thanks a lot to them and all others who are sending the problems or just ideas of the problems!

The problems was prepared by me (Edvard Davtyan). Thanks to Maria Belova Delinur for checking the English statements. The problems was tested by the same users who suggested them: unprost, Alexey Chesnokov CleRIC and Lewin Gan Lewin. Thanks a lot to all of them!

I hope you will enjoy the problems!

Good luck and have fun!

UPD1: The first part of the contest is finished. You can hack solutions.

UPD2: There are some technical problems. The phase of open hacks will be opened later (several hours).

UPD3: Editorial is ready.

UPD4: The contest is finished. We will start system testing in a few minutes.

UPD5: TOP3 of hackers:

P_Nyagolov — 31 hacks

khadaev — 27 hacks

halyavin — 23 hacks

Hi all!

VeeRoute Marathon starts today: it is a programming competition that is organized by VeeRoute and lasts from February 29 to March 14. We have already posted information about the Marathon here on Codeforces, and now we would like to tell more about its organizer.

VeeRoute is a Russian IT-company that develops solutions for logistics optimization. Even though VeeRoute is a young company, its growth has been very rapid: the staff has doubled in the last few months, and the company is preparing to enter the international markets. There are two offices: in Moscow and Saint-Petersburg. VeeRoute is a very attractive workplace for talented and ambitious programmers, because everyday tasks there are challenging and interesting, and the development department is headed by Andrey Lopatin, a two-time world champion in programming.

VeeRoute’s ambition is to become a world leader in the field of IT solutions for logistics optimization. Every day logistics becomes more and more complex, and the key to new challenges is automatization of logistics processes and its management in real time. VeeRoute follows these trends by creating its own Scheduling & Dispatching platform.

If you get excited about challenging and interesting programming problems, if you are good with algorithms and data structures, then VeeRoute Marathon is for you! Register here: http://codeforces.net/contests/636.

Participants will have to solve a certain optimization problem, similar to those solved by VeeRoute team daily. Do your best and draw VeeRoute’s attention to your talent! VeeRoute is trying to make the world a better place, and looking for individuals who share the same goals and vision.

Good luck and have a nice contest!

Hi all!

From February 29 to March 14, a contest supported by company VeeRoute will be held on Codeforces. VeeRoute is a young and ambitious IT company which specializes in automation of transportation logistics.

Participants will have to solve a certain optimization problem as best as they can. The problem is similar to the ones that are being solved by VeeRoute daily. As the competition format is very different from a standard Codeforces round, the contest will be unrated.

Participants

We invite everyone who is fond of interesting programming challenges and well-versed in algorithms and data structures. The contest is for individuals. There are no restrictions on age or division.

Prizes

After the final testing is over, the winners will be announced, and the following prizes will be awarded:

• I place — iPhone 6S or Nexus 6P at the winner’s choice.
• II place — any mechanical keyboard by Das Keyboard.
• III place — any board game of the Ticket to Ride series.

Additionally, top 30 contestants will receive a T-shirt with the sponsor’s logo.

Good luck and have a nice contest!

Hello everyone!

The final round of the 8VC Venture Cup will be held on Feb/28/2016 18:10 (UTC). ecnerwala and I are the problem setters. We want to thank GlebsHP and vnovakovski for help in preparing the contest, stella_marine for fixing the statements, and MikeMirzayanov for creating the Codeforces platform.

The contest is by invitation only to the top 200 contestants and top local contestants from Round 1 and contains six problems. We will also hold rated, out-of-contest participation for both div1 and div2 contestants — all three groups will feature slightly different problemsets. Local contestants will compete onsite in Silicon Valley. OpenGov, one of the featured 8 | VC companies, has been generous to host this competition at their offices; see more details about this awesome company below:

OpenGov transforms the way the world analyzes and allocates public money. With more than 700 government customers across 45 states in a rapidly expanding network, OpenGov is the market leader in cloud-based financial intelligence, budgeting, and transparency for government. The OpenGov platform transforms government financial data into intuitive, interactive visualizations for both internal government users and citizens.

ABOUT 8 | PARTNERS

8 | Partners, which consists of Joe Lonsdale (co-founder of Palantir) and his core team from Formation | 8, is a Silicon Valley venture capital firm that invests in industry-transforming technology companies. The team's investment portfolio includes companies such as those featured below, and a host of other top technology platforms that leverage modern algorithms and data science to power their core business processes. If you are interested to connect, please take a look at http://www.codeforces.com/8vc/apply.

PRIZES

• Overall 1st place — $2500
• Overall 2nd place — $1000
• Overall 3rd-5th places — $500 each
• Overall 1-50th place — t-shirts with 8 | VC and company logos
• Local Winner — Dinner with Joe Lonsdale (founder of Palantir, Addepar, & 8 | Partners) and other Silicon Valley technologists
• Local top finishers — Opportunity to meet with leadership from 8 | VC portfolio companies

The scoring distribution will be standard for all three divisions: 500 — 1000 — 1500 — 2000 — 2500 — 3000

Good luck!

UPD: Due to onsite awards presentation, we will hold final system testing until around one hour after the end of the contest.

Congratulations to the top overall contestants:

1. tourist
2. Egor
3. ikatanic
4. enot110
5. DemiGuo

As well as the top onsite contestants:

1. winger
2. waterfalls
3. KADR

Editorial can be found here.

Thanks for participating!

Hello Codeforces,

Manthan, Codefest 16 will take place on Friday 26th February, 2016 10:35PM IST with a duration of 2.5 hours. The round is rated and consists of 8 problems.

The Department of Computer Science and Engineering is conducting Codefest from 25th-28th February. Manthan( मंथन in Hindi, meaning Brainstorming), the algorithmic programming contest under the banner of Codefest, is being held as a special Codeforces round. The round follows regular Codeforces rules. The prizes for Manthan are being sponsored by Walmart Labs.

The round is prepared by One_touch_finish, mkrjn99, FoolForCS, IITianUG and code_note.

We express our heartiest thanks to GlebsHP and AlexFetisov for their help in preparing the contest and MikeMirzayanov for the awesome Codeforces and Polygon platforms!

Prizes:

Don't forget to register for Manthan at our website also to be eligible for prizes.

Overall 1st place: ₹25,000 Overall 2nd place: ₹15,000 Overall 3rd place: ₹10,000

1st place in India: ₹15,000

1st place in IIT(BHU) Varanasi: ₹4,000 1st place in freshman year, IIT(BHU) Varanasi: ₹1,000

About Codefest: Citrix presents Codefest is the annual coding festival of the Department of Computer Science and Engineering, IIT (BHU) Varanasi, which is held online and is open to participation by all! Register on the Codefest website now! Free .tech domain for everyone who registers on the Codefest Website. Total prizes worth ₹450,000/- up for grabs with events covering domains from Math, Machine Learning Cryptography and Capture The Flag style competitions. Go to the Codefest website to find out more!

Update: The editorials have been posted: http://codeforces.net/blog/entry/43392

From 26 of March to 2 of April 2016 the Moscow Pre-Finals ACM ICPC Workshop is going to be held at Moscow Institute of Physics and Technology. Registration form.

The event is an international student training camp that is aimed at preparing competitive programming teams to ACM ICPC World Finals 2016 and contests of the next season. The schedule features six training days and with daily contests, problem analyses, lectures, upsolving time, evening sports and other leisure activities, and one free day. The official language is English.

The Workshop will be based on the one and a half divisions scheme. (similar to the scheme of Moscow International Workshop ACM ICPC). The first division is for teams that passed into World Finals and for teams with the same level, the second one — for teams willing to practice for the future season.

The participation fee is 19000 rubles per participant for Russian students or $360 per participant for non-Russian students. This cost includes the curriculum, meals and accomodation at the MIPT campus, as well as the sports and travel programme for weekends.

Participants and teams that are willing to take part in the training need to pass the preliminary registration until 1 March, 2016. For any occuring questions, leave messages on the organizing committee email: [email protected].

Information site: http://it-edu.mipt.ru/ru/spring_training_2016. The Workshop is organized by the universities MIPT and ITMO.

Hello, Codeforces!

I have the pleasure to invite you to the round #343 which is going to take place on Saturday! This round is consisted of 5 problems and you have 2 hours (as usual) to solve them.

The problemsetters are Mohammad Amin Vahedinia (Me) (MrNull), Daneshvar Amrollahi (dkjsfkhg) and Alireza Tofighi (ATofighi). We would also like to thank Alireza Tofighi (ATofighi) and Ali Asadi (aliasadiiii) for testing this round and Ali Bahjati (LiTi) for helping us preparing this round.

We thank Gleb Evstropov (GlebsHP) for his help in preparing the contest, Maria Belova (Delinur) for translating the statements into Russian, and, of course, MikeMirzayanov for unique Codeforces and Polygon platforms.

This contest's Hero is Famile Door and his friends who are preparing his birthday party!

UPDATE 1: Scoring Distribution is 500 — 1000 — 1750 — 2000 — 2500

UPDATE 2: Editorial is ready HERE

UPDATE 3: System Testing is finished you can see the standings here: результаты

Congrats to the div2 Winners:

1. rakhashov.maksat

2. DarthMaul

3. TakeTheAegisIDontNeedIt

4. ykaya

5. abcdef6199

Also congrats to the div1 Winners:

1. Um_nik

2. anta

3. Nerevar

4. kmjp

5. vintage_Vlad_Makeev

Best of luck to everyone!

Hello, Codeforces!

Educational Codeforces Round 8 will take place on 19 February 2016 at 18:00 MSK for the first and the second divisions. You can read about educational rounds here and here. I hope that the high density of contests on Codeforces will not startle you and you will participate in ER8.

<The phrase about simple problems is added in the end>

The round will be unrated for all users and it will be held with extented ACM ICPC rules. You will have two hours to solve six problems. 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.

If you have ideas for some problems or maybe already prepared problems that you can't use in rounds or official competitions, you can write to me.

It seems that it is harder to invent interesting simple problems (like A and B) than difficult ones. So don't be afraid to suggest interesting simple or very simple tasks.

</The phrase about simple problems is added in the end>

This time (for the first time) the problemset was totally suggested by Codeforces users. The problem А suggested by user unprost. The problem B was taken form the problems sent by Bayram Berdiyev bayram, Allanur Shiriyev Allanur, Bekmyrat Atayev Bekmyrat.A. The problem D suggested by Kareem Mohamed Kareem_Mohamed (but I made it more difficult to make it more interesting for you :-)). The problem E sent Ali Ahmadi Kuzey. The problems C and F are suggested by Kamil Debowski Errichto.

Thanks a lot to them and all others who are sending the problems or just ideas of the problems!

This time the problems wasn't prepared only by me (Edvard Davtyan). Thanks a lot to Kamil Debowski Errichto who not only suggested the problems C and F, but also prepared them. Thanks to Maria Belova Delinur for checking the English statements. Also thanks a lot to Ali Ahmadi Kuzey who helped me with testing of some problems.

A few words about the problems: A) Easy problem with the long statement; B) I hope you will not write hard solution; C) It's interesting; D) It's a little technical, but contains very useful technique; E) I like this problem; F) Very cool problem if you will not solve during the contest I recommend to solve it in practice.

Good luck and have fun!

UPD1: The first phase of the contest finished. Hacks started. The editorial is ready.

By the reason that all the problems of Errichto are about a bears, below you can see the illustration for the problem C (it seems Limak is the leftmost):