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.

ACM-ICPC World Finals 2017 will begin on May 24, 2017 at 15:00 (UTC). This event is the main event of the year in the world of sports programming!

This year ICPC Regional participation included 46,381 of the finest students and faculty in computing disciplines from 2,948 universities in 103 countries on six continents. A record 50,145 students and 5,073 coaches competed in ICPC and ICPC-assisted competitions this year, setting new records in participation.

Codeforces wishes the teams to show a vivid and interesting contest 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)

Hello, Codeforces!

The ACM-ICPC World Finals 2017 event is running now. Tomorrow will be the main contest. During these days the directorate of ACM-ICPC shared some news.

• Let me remind you that this season (2016-2017) is last, when the general sponsor of the championship is IBM. For 20 years, IBM has supported ACM-ICPC, investing millions of dollars annually. Thank you, IBM! At the moment, the model is actively being worked out, when there will be not one general sponsor, but there will be a fund in which several companies will participate. At the opening ceremony the Sport Programming Foundation was mentioned. I believe this Foundation will be the main one for the future seasons of the championship. However, these are not yet close plans.

  It was announced that the next three years the general sponsor of ACM-ICPC will be JetBrains! This is amazing news. Particularly pleased that this is actually a Russian company, and its executive director Maxim Shafirov coached the team of St. Petersburg State University, which became the world champion in 2000! I'm sure that the wonderful development environment from JetBrains in the future finals of the championship will await us as a pleasant bonus.

• There is a reform of the qualifying stages of the championship. For example, now Rissian+ regional contest (NEERC) is not part of the European Regionals, but is a separate league of the Northern Eurasia. In general, eight leagues (read, super-regions) were singled out: Europe, Northern Eurasia, North America, Latin and South America, two leagues in Asia, Africa and probably Australia and Oceania. It is planned that each league will have its own separate finals with medals and the top 12 teams from each league will receive a ticket to the World Finals. While these are still distant plans, but the first steps have already been taken. Discusses its quota on the number of participations in the league finals (3 times).

• Unfortunately, this year a significant part of the teams did not receive a visa at all (5 teams) and a dozen more could not arrive completely because of the visa problems of one of the participants. Saratov State University, apparently, is among them. It was announced the decision to invite to the next Wold Finals without any selections and quota accounting for 5 teams that could not come this year. In addition, it is proposed to give a +1 year to participate (without taking into account any other requirements) to all teams that could not arrive completely.

• The next Finals will be held in Beijing, and a year later — in Kochi (India).

Such news.

Hello CodeForces Community!

I’d like to invite you to participate in CodeChef’s global annual onsite programming contest SnackDown 2017 Qualifier which starts day after tomorrow i.e. 20th May, 2017. This time there are no restrictions on team formation (except max size of two). So, that leaves us with no reason to not take part in the contest. I am certain you will enjoy not only the exciting finale setup but also the brilliant problems.

Registrations:

You can register in a team of two or can go solo into the contest. The Online Qualifier starts at 20th May,2017.

If you are yet to register, you can do so here: https://www.codechef.com/snackdown/2017

Prizes:

Along with the cash prizes for Global Winners, there are special prizes for Best School Team, Best Girls team and Best Indian Team (the total cash prizes are worth $20,500). The winning team shall win a whooping cash prize of $10,000. Top 300 Teams In the Elimination Round will get a cool SnackDown t-shirt. Every team member of the qualifying teams for the elimination round will get a domain name from Radix registry. Certificate of Participation-All the teams advancing from the Qualifiers to further rounds will receive a digital certificate of Participation from CodeChef.

Previous Years:

Last years star-studded final was won by pattern_avoid team (Gennady Korotkevich and Borys Minaiev).

Sponsorship for onsite round:

Travel expenses of the top 25 teams: Top 15 teams will be entitled for an all expense paid trip to Mumbai. The top 15 Indian teams that arrive at the finale will be entitled for an all expense paid trip to Mumbai. (Provided that they do qualify for the onsite finale. The top 10 teams are guaranteed an entry. The next 5 Indian teams have to be in top 100 of the Elimination round to be eligible for onsite finale. See rule 4 above under Onsite Finale).

For more elaborate rules click here.

Also, taking into consideration the previous discussions regarding the timing of online elimination round of the contest, the organizers had done a poll beforehand, so as to satisfy time demands by more contestants.

I hope you like the new timings and that will enjoy the contest till the very end. That will be all from my side for now. See you all at the contest. Regards, Ciao, Siba Prasad Tripathy (manvscode)