Hello Codeforces!

On June 15, 18:05 MSK Educational Codeforces Round 23 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.

The round will be unrated for all users and 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, Vladimir vovuh Petrov and me. Huge thanks to Alexey Perforator Ripinen, Alexey ashmelev Shmelev and Maxim HellKitsune Finutin for testing!

Good luck to all participants!

UPD. I am pleased to announce the 2nd Hello Barcelona Programming Bootcamp in collaboration with Moscow Workshops ACM ICPC, which will be hosted by our partner Harbour.Space University together with Moscow Workshops ACM ICPC, ITMO University, Moscow Physics and Technology University, Saint Petersburg State University and Codeforces!

LEARN MORE

UPD: The editorial is published.

Hello, Codeforces!

I am pleased to announce the 2nd Hello Barcelona Programming Bootcamp in collaboration with Moscow Workshops ACM ICPC, which will be hosted by our partner Harbour.Space University together with Moscow Workshops ACM ICPC, ITMO University, Moscow Physics and Technology University, Saint Petersburg State University and Codeforces!

The boot camp will be held from September 27th to October 5th in Barcelona. This time it will be at the beautiful and technologically mind-bending Media-TIC building — the Smart Building of Tomorrow.

Media-TIC building — the Smart Building of Tomorrow

The world's greatest coaches will be attending: Andrew andrewzta Stankevich, Michael Endagorion Tikhomirov, Gleb GlebsHP Evstropov, Artem VArtem Vasilyev and other world renowned Russian coaches. As a coach, I will come too. The Chief Judge of the camp is Oleg snarknews Khristenko. Seriously, it will be a unique opportunity for teams around the world to learn from such well-known and successful coaches in the ACM-ICPC world.

Having visited the first Hello Barcelona programming Bootcamp in February, I left the event feeling inspired from the overall atmosphere. I am sure that all teams received an immense amount of knowledge and skills. As one of the coaches, all of the flattering reviews about the camp from the participants were pleasant for me to hear. I am very glad that these camps are becoming regular. Harbour.Space University and Moscow Workshops ACM ICPC have done a job worthy of admiration!

The Bootcamp will be split in two divisions:

• Division A. Designed to prepare students to excel and win medals in the next ACM-ICPC World Finals.

• Division B. Designed to help teams prepare for the next season of ACM-ICPC Regionals and international competitions. This is an appropriate introduction for teams and students new to the world of ACM ICPC and competitive programming competitions in general. The Division B curriculum features thematic lectures and contests.

The participation fee is unchanged: €1270 per person (cultural program, accommodation and half-board meals included).

Single participants and teams must register by July 1st, 2017 to receive the 15% off-Early Bird Discount, or the 20% off-Loyalty Discount, which is awarded to teams that participated in previous Moscow Workshops ACM ICPC boot camps.

You can ask any questions by email: [email protected]

Hope to meet you on the Bootcamp, Mike Mirzayanov

In order to experience the atmosphere of the event, I suggest you familiarize yourself with the photos and videos from the 1st Hello Barcelona programming Bootcamp in collaboration with Moscow Workshops ACM ICPC.

Can't download http://assets.codeforces.com/photos/barcelona-2017-1/list.txt [tried twice].

418 I'm a teapot

Hi everyone! >///<

I'd like to invite you to Codeforces Round #418 which begins at 15:05 MSK on 7 June. Please note that the timing is unusual.

This is my first round here! KAN reviewed the contest and helped me through the preparation process, while Alladdin, FalseMirror and Tommyr7 tested all the problems, and MikeMirzayanov and the awesome Codeforces and Polygon platforms made all this happen miraculously. This wouldn't have been possible without your efforts!

The round is rated for the second division, and participants from the first division can take part out of competition. As usual, there are five problems and two hours to solve them. The problems will feature... Well, let's wait and see :)

The scoring distribution will be announced later.

Hope everyone few bugs and fair ratings. Looking forward to seeing you then!

UPD 1 Scoring will be 500-1000-1750-1750-2500. It's recommended to read all problems' statements so as to find the problems that suit you — we tried quite hard to make them clear and interesting.

UPD 2 The round is delayed for 10 minutes due to technical issues. Apologies.

UPD 3 System test is done. Congratulations to the winners!

Div. 2 Top 5

1. memanon
2. marmoset
3. liu_runda
4. yieldar
5. Krydom_Yuudachi

Overall Top 5

1. xumingkuan
2. HellKitsune
3. natsugiri
4. yancouto
5. irkstepanov

Hope you all enjoyed the contest. You all did a great job! The editorial is on the way, please be patient :)

UPD 4 For the impatient, here are the tutorials for problems A to C. More are coming!

UPD 5 The complete editorial is out. Cheers!

Hello Codeforces!

On June 05, 18:05 MSK Educational Codeforces Round 22 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 and Codeforces in the blog post.

The round will be unrated for all users and 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. We tried to design the problems in such a way that both beginners and experienced programmers can find something interesting in the contest.

The problems were prepared by Mikhail awoo Piklyaev, Vladimir vovuh Petrov and me. Huge thanks to Maxim HellKitsune Finutin and Alexey ashmelev Shmelev for testing the contest!

Good luck to all participants!

UPD: The editorial is published.

Hello!

We have organized information about cities and countries. Before users could add this information themselves, which led to duplicates, incorrect names, grammatical mistakes, etc. I parsed geodata, taking cities with population of 500+ people. It turned out there are more than 120,000 such ones. In addition, searching for cities has been improved — supported search by historical, national and other names.

Thus, duplicates of cities were merged and random garbage was deleted.

If for some reason your city has been inappropriately removed from the profile, try to set it again. If you can not find your city in the list, let me know about this and it will be added.

Thanks.

Hello Codeforces!

I would like to invite you to Codeforces Round #417 that will take place tomorrow on June 1st, 2017 at 17:05 MSK.

This is my first round. Great thanks to KAN for his efforts and help in the round preparation, mike_live and 300iq for testing the problems, and MikeMirzayanov for the awesome Codeforces and Polygon platforms.

The round is rated for the second division. Participants from the first division can take part out of competition. As usual, the participants will be given 5 problems and two hours to solve them.

I hope you will find the problems challenging and interesting!

UPD 1: Scoring disrtibution: 500 — 1000 — 1500 — 2000 — 2500.

UPD 2: Due to a technical issue, the contest is delayed by 10 minutes.

UPD 3: Contest is over. Congratulations to the winners!

Div2 Winners:

1. TERESO

2. neverfirst

3. _luckyE

4. zstu_jack

5. jiyutian

Div1 Winners:

1. y0105w49

2. _Reborn_

3. eddy1021

4. chemthan

5. KrK

UPD 4: Editorial

Hello CodeForces! This year again, I'd like to invite you to the online mirror of an open championship of Switzerland called the Helvetic Coding Contest. A mirror was also held last year — see here: Helvetic Coding Contest 2016 online mirror (teams, unrated)

The Helvetic Coding Contest is a yearly contest held at the EPFL in Lausanne by the PolyProg association. The contest itself took place on April the 1st, but the online mirror is scheduled on Sunday, 28th of May, 11:05 Moscow time. The duration is 4:30.

Rules:

• you can participate in teams or individually (1-3 people),

• standard ACM-ICPC rules (no hacking),

• the contest is not rated,

• if you have participated in the onsite contest, please do not participate in the mirror.

You will help us find the cow Heidi and participate in some April-Fools-Day confusion. The contest will feature 5 series of 3 related tasks with increasing difficulty (easy/medium/hard). Sometimes it may be the case that a solution for the hard version solves all of them, but usually not. We think that the problemset is diverse and interesting, and while the contest is ACM-style, you will find that some problems are not so standard. Most easy&medium problems are even solvable in Python, so you can also recommend this contest to your newbie friends :)

Acknowledgments: the problems were set by Christian Kauth, boba5551, meret, DamianS and myself. Thanks also go out to people who helped with the statements and testing: maksay, Michalina Pacholska (who also draws the cows), Benjamin Schubert, Aleksa Stanković, Ruofan Zhou; Tatiana_S for Russian translations and KAN for CodeForces coordination, as well as everyone involved in the actual onsite contest, who are too many to name here. We also thank the sponsors Open Systems and AdNovum. Lastly, thanks to MikeMirzayanov for CodeForces and Polygon (which was used to prepare the problems).

Finally, in a bit of autopromotion, note that you can use Hightail to automatically test your solutions :) Good luck!

After-contest UPDATE:

>>> Editorial <<<

Feel free to ask questions in this topic.

Thanks to everyone who participated! We hope you have enjoyed the problems. Congratulations to the winners:

1. ★SweeT DiscoverY★: dotorya, zigui, molamola. (solved all problems!)

2. japan-cookie: sigma425, sugim48, yosupo (solved all problems!)

3. HSE Bluebell: Um_nik, Kronecker

4. Veteran: I_love_Hoang_Yen, chemthan, ngfam_kongu

5. m(_ _)m: tmt514, Shik, dreamoon_love_AA

6. never red: xxTastyHypeBeast666xx, gongy, rnsiehemt

7. rng_58

8. (｀・ω・´): FizzyDavid, ohweonfire

The winners of the onsite contest (Petr Team) also solved all problems.

See you again next year!

Hello everyone!

27 May, 12:35 MSK new codeforces round takes place for participants from the second division. Participants from the first division can participate out of competition. Round consists from 5 problems, and you will be given 2 hours to solve them. Pay attention on round start time.

The problems will be almost the same as on Open Olympiad of Mozyr State Pedagogical University, which takes part parallel to the round. The full problem set would be in codeforces gym soon. I am also going to tell you about the Olympiad a bit later.

• The problemsetters are: me (Vladislav Vishnevski), Valery Kameko (v4lerich) and Yury Shilyaev (hloya_ygrt).
• The testers are: Alex Kernozhitsky (gepardo), Arseniy Kolosov (KArs) and Ilya Klimko (klinchuh).
• The coordinator of the round was Alexey Vistyazh (netman).
• Alex Dryapko was reading the statements (sdryapko).
• And of course, the round would be impossible without Mike Mirzayanov (MikeMirzayanov), author of polygon and codeforces systems.

Thanks everyone for contribution you did to the setting of the round.

The main character of the round is Vladik, who loves to solve problems and himself.

Good luck to everyone! :)

UPD 500-1000-1500-2000-2500

UPD Editorial.