Hi, Codeforces!

I'm glad to invite you to take part in Codeforces Round #720 (Div. 2), which will take place on May/07/2021 17:35 (Moscow time). The round will be rated for the participants with a rating lower than 2100. Participants from the first division are also welcomed to take part out of competition.

You will be given 2 hours 15 minutes to solve 5 problems. All the problems were created and prepared by me. One of the problems is interactive, please read the guide of interactive problems before the contest.

Huge thanks to those who helped make this round possible:

• Fliahin for being the first who gave feedback and helped with ideas on some problems.
• Denisov for providing priceless feedback during the entire creation of the round.
• KAN and Aleks5d for their excellent coordination.
• Valera_Grinenko, PurpleCrayon, BOGDAN_, okwedook, namanbansal013, chctxdy68, ermakov22, Denisov, 4qqqq, alexX512, IaMaNanBord, perekopskiy and never_giveup for testing and providing invaluable feedback.
• MikeMirzayanov for Codeforces and Polygon platforms.

I tried my best to create interesting problems and clear statements, so don't forget to read all ones :)

Scoring: $$$500-1000-1750-2250-2750$$$.

Hope you enjoy it!

Unfortunately, due to Internet provider network issues, we have to postpone the round. The current plan, that the round is postponed by 24 hours, will start on May/05/2021 17:35 (Moscow time).

Hello, Codeforces!

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Hello! Codeforces Round #719 (Div. 3) will start at May/05/2021 17:35 (Moscow time). You will be offered 7 problems with expected difficulties to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have a rating 1600 or higher, can register for the round unofficially. The round will be hosted by rules of educational rounds (extended ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round, it will be a 12-hour phase of open hacks. I tried to make strong tests — just like you will be upset if many solutions fail after the contest is over.

You will be given 7 problems and 2 hours to solve them.

Note that the penalty for the wrong submission in this round (and the following Div. 3 rounds) is 10 minutes.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as trusted participants of the third division, you must:

• take part in at least two rated rounds (and solve at least one problem in each of them),
• do not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.

The problems for this round were invented by MikeMirzayanov, Supermagzzz, Stepavly and Aris_244_.

Thanks to Gassa, BledDest, Programmer, bugdone, ruban, RedAnt, songsinger and Gornak40 for help with testing the round.

Thanks to MikeMirzayanov for platforms and coordination of our work. Good luck!

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Editorial is ready!

Hi!

On May/02/2021 17:35 (Moscow time), we will host Codeforces Global Round 14.

This is the second round of the 2021 series of Codeforces Global Rounds. The rounds are open and rated for everybody.

The prizes for this round:

• 30 best participants get a t-shirt.
• 20 t-shirts are randomly distributed among those with ranks between 31 and 500, inclusive.

The prizes for the 6-round series in 2021:

• In each round top-100 participants get points according to the table.
• The final result for each participant is equal to the sum of points he gets in the four rounds he placed the highest.
• The best 20 participants over all series get sweatshirts and place certificates.

Thanks to XTX, which in 2021 supported the global rounds initiative!

All problems were written and prepared by me FieryPhoenix and dragonslayerintraining.

Huge thank you to everyone who made this round possible:

• adedalic for coordinating our round!
• frodakcin, Xylofo, awoo, prabowo, Shanks, Roundgod, thenymphsofdelphi, Nezzar, BledDest, PurpleCrayon, chctxdy68, nchn27, Aaeria, not_tehlka, namanbansal013, growup974, Saurabh_yadav, HIS_GRACE, Amazed, AlanTheMankey for testing and valuable feedback!
• MikeMirzayanov for Codeforces and Polygon platforms!
• You, for being you!

You will have 3 hours to solve 9 problems. Scientific studies have shown irrefutable evidence that upvoting this blog and participating in this round will lead to longevity and happiness. GLHF!

UPD: The scoring distribution is 500 — 1000 — 1500 — 2000 — 2750 — 3250 — 3500 — 4250 — 5000

UPD: Editorial is here!

UPD: Congratulations to the winners!!

1. Radewoosh
2. ksun48
3. Um_nik
4. Benq
5. yhx-12243
6. tourist
7. duality
8. jiangly
9. LJC00118
10. NotaMotuaQAQ

Codeforces, welcome!

Registration for the ML competition from Raiffeisenbank that starts on May 17 is now open. The prize fund of the championship is 700,000 rubles.

All terms of participation were developed by the Raiffeisenbank eFX trading team in collaboration with Codeforces. Huge thanks to geranazavr555 for the testing and great advice and MikeMirzayanov for Codeforces systems.

Participants are invited to build a predictive model based on the provided historical data.

We expect winning teams to provide descriptions of their solutions in Russian, cash prizes will be contested only among Russian residents.

Prizes:

• 1-4 places — 100K rubles each
• 5-10 places — 50K rubles each
• 1-60 places — merch packages

Registration is open up to the 22th of May, inclusive. Please fill in the contest registration form.

Hello Codeforces!

On Apr/29/2021 17:35 (Moscow time) Educational Codeforces Round 108 (Rated for Div. 2) 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.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6 or 7 problems and 2 hours to solve them.

The problems were invented and prepared by Roman Roms Glazov, Adilbek adedalic Dalabaev, Vladimir vovuh Petrov, Ivan BledDest Androsov, Maksim Neon Mescheryakov and me. Also huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Good luck to all the participants!

Our friends at Harbour.Space also have a message for you:

Hey, Codeforces!

Once again, it is time for another exciting scholarship opportunity from Harbour.Space!

This time we have partnered with PhazeRo to open the door for an exciting career in technology for the most talented people in our network.

In partnership with PhazeRo, we are offering a full scholarship to study for a Master’s in Data Science at Harbour.Space while working as a Junior Data Scientist at PhazeRo!

Scholarship Requirements:

• Bachelor's Degree
• Professional fluency in English
• Proficiency with data mining, mathematics, and statistical analysis.
• Experience with Tableau, SQL, and programming languages (i.e., Python, R, Java)

Scholarship Highlights:

1. Study in Europe’s most exciting tech cities
2. Full tuition fee covered (€22,900)
3. Competitive compensation for the internship at PhazeRo (€700 / month)
4. Opportunity to join PhazeRo full-time after graduation

Some of the advantages of working at PhazeRo:

• Possibility of a job upon graduation
• Immerse into an International Company
• Diversity Program
• Professional Development
• Be part of a company that is building the region's largest engineering team

We have previously partnered with other companies like OneRagtime, Hansgrohe, Coherra, and Remy Robotics to empower young talents around the world and help them boost their tech career.

We are always happy to see Codeforces members join the Harbour.Space family. Apply now to get a chance to learn from the best in the field and kickstart your career!

Keep in touch and follow us on LinkedIn for more scholarship opportunities. And follow us on Instagram to evidence student life, events, and success stories from our apprenticeship program students.

Good luck on your round, and see you next time!

Harbour.Space University

Congratulations to the winners:

Congratulations to the best hackers:

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

UPD: Editorial is out

Hello Codeforces!

Contest 2050 and Codeforces Round #718 (Div. 1 + Div. 2) will take place on Apr/23/2021 17:35 (Moscow time). It's rated for everyone! The score distribution is 500--1250--1500--1750--2500--3000--3000--4000. You will have 2 hours and 45 minutes to solve 8 problems.

Contest 2050 is initiated by volunteers of the 2050 Conference. You can find out what is 2050 at the end of this blog.

The contest is prepared by

• Fulisike, littlelittlehorse, Retired_MiFaFaOvO, xyz2606

and we'd like to thank

• KAN, Nebuchadnezzar for their excellent coordination.
• absi2011, chitanda, Gromah, Itst, _cherry_, Aaeria, HIS_GRACE, A.K.E.E., namanbansal013, Miracle03, yaoR, sshwyR, chenjb for testing the round.
• MikeMirzayanov for the great codeforces and polygon platforms.

See you on Friday and good luck!

We have the following introductory message by the 2050 volunteers:

2050 aims to equip young people to take action and to become volunteers. Every 'last weekend' of Apr, together with the youth, we celebrate the technology at Yunqi Town, China. 2050 is a volunteer-only, not-for-profit unconference.

"Most of the conferences in China are held for those who are already successful in their careers, but none targets young people. 2050 wants to fill the gap, giving Chinese youth a stage to make their own voices heard and maximize their energy and talent," said Dr. Wang Jian.

What to expect at 2050?

At 2050, we call it containers. There are 10 containers: 2050 Youth; Migratory Bird Program; Game On; Mindnet; Youth Stage; Starry Night Camping; Everything Grows; Explorer Space; New Gen Forum; Youth Reunion.

Special arrangement of this year

This year, because of the pandemic and travel restriction, many friends from overseas cannot join us in Hangzhou. This however, cannot stop us from connecting with each other. 2050 will be connecting with 100 cities, to dial in volunteers who cannot join us onsite.

The road to championship @ new gen forum

Algorithms and programming are their pleasures of life. With the belief of victory, they defeated the most powerful opponents. They worked hard to explore the boundaries of human intelligence on the road to the ultimate. We invite the top competitive programming players around the world to share their journeys on Saturday at 23:00~24:00 (UTC+8). If you are interested, please message littlelittlehorse.

Find out more at https://2050.org.cn/en/.

UPD. Score distribution 500--1250--1500--1750--2500--3000--3000--4000

UPD Congratulations to the winners

1. Benq
2. Um_nik
3. mnbvmar
4. Radewoosh
5. y1s1

Editorial

Editorial

Rucode Festival is a great opportunity to prove yourself and get experience in programming competitions. The Championship will be held on 25 April in two different levels of complexity: for A/B divisions and for C/D divisions. The tasks will be in English and in Russian.

We welcome teams from 1 to 3 people.

The tasks are made by the leading Russian universities professors, champions of international competitions and coaches of Moscow Workshops.

To take part please register here until 24 April, 23:59 (Moscow)

Schedule:

• Trial round: 10:30 — 11:00

• Contest: 11:00 — 16:00

See you at #RuCode!

It's me again!

Codeforces round #717 will take place on Apr/21/2021 16:35 (Moscow time), an hour early than the usual timing. It's rated for the second division, but, as usual, first division participants can take part out of competition.

The problems were created by me, and some of them are based on the Egyptian IOI qualification. I'd like to thank:

• KAN and Aleks5d for their excellent coordination.
• Akulyat, __cucumber__, Randle, Riladavin, Waley, MForest, _Stefan_, RabbitPower, and the official contestants, I guess, for testing the round.
• MikeMirzayanov for the great Codeforces and Polygon platforms.

You'll be given 5 problems, but this time you'll have 2 hours to solve them.

UPD: the scoring distribution will be 500-1000-1500-2000-2750.

UPD: the editorial.

UPD: congratulations to the winners:

Div.1:-

1. LJC00118
2. antontrygubO_o because he has to get a mention
3. Mehrdad_Sohrabi
4. zscoder
5. SSRS_

Div.2:-

1. __fishingprince__
2. Dolodu123
3. alya_wow
4. nxa_k_o
5. Kazaoka_Mari

Good luck & Have fun :D