By mtnshh, history, 30 hours ago, In English

The Programming Club, IIT Indore is proud to present our flagship event, Divide By Zero! The contest will take place on Apr/11/2021 17:35 (Moscow time). This round will be rated for all participants with a rating lower than 2100.

Divide By Zero 2021

Thanks to the following people for making the round possible:

There are 6 problems, and 2 hours to solve them. The points distribution will be updated later.

Update: The scoring distribution is 500 -- 1250 -- 1500 -- 2000 -- 2750 -- 3000.

PRIZES: Twenty Codeforces T-shirt will be given to:

  • Top 10 Indian Participants
  • Random 10 from top 100 (rank 11-100) Indian participants

Hope you guys enjoy the contest! See you on the leaderboard!

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By Stepavly, 2 days ago, translation, In English

Hello, Codeforces!

<almost-copy-pasted-part>

Hello! Codeforces Round #713 (Div. 3) will start at Apr/10/2021 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 sodafago.

Thanks Gassa, darkkcyan, bfs.07, Tzak, songsinger, Mukundan314, iankury, drunya, sodafago, ChOmPs, Programmer, Khairy, IITianUG, Rox for helping with testing the round!

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

</almost-copy-pasted-part>

Editorial: https://codeforces.com/blog/entry/89535

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By MikeMirzayanov, 44 hours ago, In English

Hi Codeforces!

Yes, I know it's already April. Time flies so fast lately! Exactly a year ago we were just learning all the "delights" of lockdown.

So let's remember this 2020! What was it like? I don't know about you, but we had a hell of a lot of work.

I will now show you some graphs and you will be very surprised. Lockdown effect? Of course, but we did our best too.

Many thanks to everyone who did not stand aside! In 2020, we celebrated our 10th anniversary and crowdfunding money helps us grow and move forward. You helped us and each other. Thank you. Thank you for your contribution!

We've been working hard all year to make this community a better place. Did it work out? It's up to you to judge. Many thanks to everyone who invested time and effort:

Time to take stock of 2020.

Partner Events

We are pleased to hold programming competitions with companies or for companies. I'm sure this is a great way to support the community of young programmers and hire talented candidates. Here is a list of our main partners this year:

  • Telegram and personally Pavel Durov is supporting Codeforces activities for many years, every regular round is held with their help, thank you!
  • ICPC — in 2020 we held several joint events (and we liked it!), I hope there will be more
  • Mail.Ru — Technocup and Russian AI Cup
  • VK, VK Cup — now a personal multi-track competition for Russian-speaking programmers
  • XTX Markets, Codeforces Global Rounds — a series of 6 rounds with a separate scoring and souvenirs for the best participants
  • Harbour.Space University — a series of educational rounds, the selection of summer school Tech Scouts
  • JetBrains, Kotlin Heroes Rounds — Kotlin programming language contests
  • Huawei — research competitions (marathons) with elements of machine learning
  • Raiffeisenbank — round for both divisions with cool prizes
  • Grakn Labs — round for both divisions with money prizes
  • Microsoft, Microsoft Q # Coding Contest — unusual quantum computing competition

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By NercNews, 11 days ago, translation, In English

text

Hello everyone!

After all online qualifiers, we are pleased to announce that the Northern Eurasia Finals and ICPC 2021 semi-final offline stage will take place this weekend on April 3-4!

ICPCLive broadcast Standings

Mirror Problems Problems solutions

In December 2020, we announced that 50 student teams out of 330 were selected for the Northern Eurasia Finals. Most of the teams will compete in St. Petersburg. Still, some teams will compete at Minsk, Tbilisi, and Riga sites due to travel restrictions between countries.

NERCNews is going to monitor the championship and report on the main events! We will post links to the results table, contest tasks, contest mirror, and analytics published on the official website.

UPD today were qualified for ICPC 2021 World Finals next 12 teams:

  • SPb ITMO: Insert your name (Budin, Korobkov, Naumov)
  • HSE: Overtrained (Gorokhovskii, Safonov, Rakhmatullin)
  • Moscow SU: Nonames (Koshelev, Chunaev, Kalendarov)
  • St. Petersburg SU: LOUD Enough (Bochkov, Makarov, Gaevoi)
  • Saratov SU: N (Petrov, Piklyaev, Meshcheryakov)
  • SPb HSE 1: Lemon Tree (Makhnev, Surkov, Alferov)
  • Belarusian SU: 3 (Klimasheuski, Paliukhovich, Filinovich)
  • Moscow IPT: LinkCat (Zgursky, Gaponov, Surkov)
  • Kazan FU: AJ (Ilikayev, Yagafarov, Kapralov)
  • NNSU: 1 (Khlyustov, Ryabchikova, Emelin)
  • Tolyatti SU: A (Zakharov, Sabirov, Panin)
  • IITU: 1 (Baimukanov, Sardarbekov, Kyzyrkanov)

Also, join the traditional ICPCLive team online broadcast from the site in St. Petersburg. The schedule for both days can be found here.

We have compiled a list of teams grouped by ratings, which will be especially interesting to follow. What are your predictions? Favorites?

Team Contestant 1 Contestant 2 Contestant 3 Rating
HSE: Overtrained Ramazan Rakhmatullin
never_giveup
Maksim Gorokhovskii
Maksim1744
Ivan Safonov
isaf27
8672
SPb SU: 25 Egor Gorbachev
peltorator
Semen Petrov
Semenar
Dmitriy Belichenko
Dmitriy.Belichenko
7970
SPb SU: Cheba Kings Saveliy Grigoryev
sava-cska
Andrey Efremov
receed
Mikhail Ivanov
orz
7967
SPb ITMO: Insert your name Nikolay Budin
Nebuchadnezzar
Stanislav Naumov
josdas
Roman Korobkov
romanasa
7863
SPb SU: LOUD Enough Ivan Bochkov
gnomina007
Vladislav Makarov
Kaban-5
Nikita Gaevoi
nikgaevoy
7608
MIPT: Malaya Bronnaya Yury Semenov
SYury
Maksym Machula
mHuman
Artem Komendantian
komendart
7529
HSE: Sleeveless shorts Philipp Gribov
grphil
Fedor Kuyanov
Kuyan
Semyon Savkin
cookiedoth
7410
SPb HSE 1: Lemon Tree Vasily Alferov
platypus179
Konstantin Makhnev
kokokostya
Maksim Surkov
maximumSHOT
7370
Belarusian SU 1 Aliaksandr Kernazhytski
gepardo
Dzianis Kim
kimden
Ivan Lukyanov
greencis
7377

Share your impressions and photos on social networks using hashtag #NERC.

Who will represent the Northern Eurasian Region in the ICPC 2021 Final whenever it happens? We will find out this Sunday! Stay tuned!

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By 1-gon, history, 10 days ago, In English

omg hi!

I am pleased to invite you to participate in Codeforces Round #712 (Div. 1) and Codeforces Round #712 (Div. 2)! You will be given 6 problems and 2 hours 15 minutes to solve them. I'm happy to announce the theme of this round is déjà vu!

I would like to thank the following people:

Make sure you read all problems, and I'm happy to announce the theme of this round is déjà vu! Good luck, have fun!

The score distribution will be announced immediately because you deserve it ❤️:

Div. 1: 750 — 1000 — 1250 — 1750 — 2500 — 4000

Div. 2: 500 — 1000 — 1750 — 2000 — 2250 — 3000

UPD: Editorial

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By Nickolas, 3 weeks ago, In English

The contest is over; I hope you enjoyed it! The editorial is available here.


The 9th April Fools Day Contest will take place on Thursday April 1st. This is a joke competition in which solving the problem is often easier than figuring out what the actual task is.

In this round you'll be given several weird problems and 2 hours to solve them. The contest will use ACM ICPC rules (no hacks, the standings are decided by the number of solved problems and penalty time earned on them), and it will be unrated. You can submit solutions in any language allowed by Codeforces, unless the problem says otherwise. To get an idea of what the contest will look like, you can check out the contests of the past years: 2012, 2013, 2014, 2016, 2017, 2018, 2019, 2020.

Good luck, and have fun!

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By sigma_g, history, 2 weeks ago, In English

Hello all!

We are proud to invite you to CodeCraft-21, which takes place on Mar/29/2021 17:35 (Moscow time). It is rated for all Div2 participants (rating under 2100).

This contest comes under Threads'21, as a part of our annual techno-cultural fest Felicity, IIIT Hyderabad. We have special prizes for Indian participants!

You will be given six problems to solve in a duration of two hours.

We have tried our best to keep clean statements, useful samples with good explanations, and strong pretests! We have written step-wise editorials, and will also release video editorials!

We would like to thank these amazing people for helping make the contest happen:

There will be an interactive problem! You are recommended to read the corresponding guide.

We hope you enjoy the contest as much as we did preparing it! Good luck!

Update: The scoring distribution is 500/1000/1750/2500/2500/3000.

Update: Editorial is up! Video editorials available on our YouTube channel.

We are sorry for the sudden increase in difficulty from C to D. Nonetheless we hope you enjoyed the problems! :)


PRIZES: The following twenty lucky participants receive a tshirt:

  • top 10 Indian participants
  • random 10 from top 100 (ranks 11-100) Indian participants

These ranks are determined from the combined unofficial ranklist. We are coordinating with the CF team for the tshirt design, and we'll update the blog post when it is finalized. We also have INR 7K worth prizes exclusively for IIIT-Hyderabad students!

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By Supermagzzz, 3 weeks ago, translation, In English

Hello, Codeforces!

<almost-copy-pasted-part>

Hello! Codeforces Round #710 (Div. 3) will start at Mar/25/2021 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 sodafago.

Thanks to darkkcyan, bugdone, harlequen, iankury, bfs.07, songsinger, infinitepro, sodafago, Gassa, Rox, sharepoLOVEDDD for testing this round.

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

</almost-copy-pasted-part>

UDP: Editorial is ready

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By JetBrains, history, 3 weeks ago, translation, In English

Hello Codeforces!

The sixth round of the Kotlin Heroes series recently finished! All the rounds are available to be used for practice here: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round and Episode 6). Thanks to everyone who participated – you inspire us to work even harder on the problems for the next round, and we think you’re really going to like them!

Congratulations to the top three contestants:

  1. tourist
  2. Egor
  3. Tlatoani

A Kotlin Heroes t-shirt and exclusive Kotlin stickers will be presented to:

  1. tourist
  2. Egor
  3. Tlatoani
  4. eatmore
  5. uwi
  6. Benq
  7. Geothermal
  8. TadijaSebez
  9. Maripium
  10. Maksim1744
  11. pashka
  12. Heltion
  13. dalt
  14. galen_colin
  15. tabr
  16. SYury
  17. natsugiri
  18. Golovanov399
  19. Spheniscine
  20. Discombobulated
  21. Ra16bit
  22. Aidos
  23. yudedako
  24. nuip
  25. knightL
  26. golikovnik
  27. wifiiii
  28. Fortin
  29. majk
  30. WiwiHo
  31. Bench0310
  32. wu_qing
  33. Kuyan
  34. Nikitosh
  35. cjtoribio
  36. receed
  37. vadimmm
  38. SecondThread
  39. LeoPro
  40. rapira
  41. Lily
  42. nhho
  43. PavelKunyavskiy
  44. abc864197532
  45. tatyam
  46. Heart_Blue
  47. Ji_Kuai
  48. darnley
  49. Potassium
  50. 353cerega

These participants also won branded t-shirts:

  1. polingram
  2. Prateek
  3. rotavirus
  4. linjek
  5. pr3pony
  6. ostroumov
  7. harshrajani460
  8. xiaowuc1
  9. arvindf232
  10. illyakr
  11. Jetman
  12. Leksiq
  13. IceKnight1093
  14. procrastinate7
  15. man.yasakov
  16. Viktor36
  17. matvey.kazakov
  18. cmplx-xyttmt
  19. SourabhYelluru
  20. daisy_2000
  21. stanm
  22. cristian1997
  23. SerVB
  24. aaronsms
  25. chick_magnet
  26. Ditmarscehen
  27. My_password_is_qwerty123
  28. Misha_Help
  29. Sohsoh84
  30. igla
  31. ans_human
  32. mystic777
  33. __RANI
  34. staffle
  35. MissNick
  36. arpit_malhotra
  37. penad
  38. I_love_Anya_Prokopyeva
  39. son8bon
  40. RandYan
  41. adimiclaus15
  42. babkabass
  43. KKT_89
  44. nishuz
  45. BMking
  46. KEKWait
  47. Kerpoo
  48. pineapple_pasta
  49. GlobalElite
  50. aka2910

We will contact the winners soon to coordinate the delivery of your prizes!

Special thanks goes to SecondThread for streaming the solutions of the entire practice round. Check out this wonderful tutorial: https://codeforces.com/stream/203

If you are still new to Kotlin but want to give it your all in the next round, take a look at Basic Kotlin (solve Koans), Kotlin Playground, this tutorial, and these videos on competitive programming in Kotlin.

We wish you all the best and hope you enjoy coding with Kotlin!

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By KAN, 3 weeks ago, translation, In English

Hi everyone!

The Final Round of Technocup 2021 starts this Sunday, March 21, 2021 at 13:00 MSK (10:00 UTC)!

For those who want to compete on the same problems, we will hold two regular Codeforces Rounds in the evening: one for the first division, and another one for the second. The rounds are starting at Mar/21/2021 16:20 (Moscow time).

If you are a participant of the official Technocup Finals, you are not allowed to take part in the rounds in the evening. We ask participants of the official Finals not to discuss the problems in open media till evening.

The problems are prepared by: Alexander Golovanov399 Golovanov, Evgenii amethyst0 Belykh, Andrey AndreySergunin Sergunin, Alexey Aleks5d Upirvitskiy, Diego Diegogrc Garcia and me.

Also huge thanks to Bench0310, kokokostya, Um_nik, dorijanlendvaj, brunomont, Stepavly, antontrygubO_o, scnucjh, Nebuchadnezzar, wucstdio, golikovnik, kuviman, dantrag, BledDest, Supermagzzz, Maripium, geranazavr555, divanik, psevdoinsaf, Roms for testing and invaluable comments, and also to antontrygubO_o for the help in holding the mirror rounds.

Good luck!

Congratulations to winners of Codeforces Rounds!

Div. 1:

  1. ecnerwala
  2. Radewoosh
  3. Benq
  4. mango_lassi
  5. AliShahali1382

Div. 2:

  1. qwqc
  2. gezlik
  3. yanyutao
  4. fengqiyuka
  5. ykl

Thanks for participation! Editorial.

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