By sidprasad, 2 days ago, In English,

Hi Codeforces!

Programming Club, IIT Indore and Fluxus 2017 are proud to present, for the first time on Codeforces, our flagship event, Divide By Zero!

The contest is going to be held on Monday, 20th Feb at 9:35PM IST.

Prizes: Codeforces T-shirts for top 15 overall and top 15 in India.

Thanks to the following people for making this round possible:

There are 7 problems, and 2.5 hours to solve them. The points distribution will be updated later.

Fluxus is the annual techno-cultural festival of Indian Institute of Technology, Indore. It is a 3-day event and generally held in the month of February. Started in 2011, Fluxus is the largest college festival of central India.

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

UPD: The scoring is 500-1000-1250-1750-2000-2250-2750.

UPD2: Thanks a lot everyone for your participation!

We hope you all enjoyed the contest. Yes, there were a few things we could've done better, and unfortunately the system was down for a while, We sincerely thank the CF team for dealing with it in the nick of time.

This was our first (of many, hopefully) contest on Codeforces. We request you to fill in this form with your feedback so that we can do better next time. Thank you!

The following users win T-shirts! Congrats!

Overall Top 15:

  1. y0105w49
  2. W4yneb0t
  3. V--o_o--V
  4. Merkurev
  5. anta
  6. I_love_Tanya_Romanova
  7. Endagorion
  8. BigBag
  9. cubelover
  10. moejy0viiiiiv
  11. natsugiri
  12. mnbvmar
  13. halyavin
  14. Shik
  15. TheLightning

Indian Top 15:

  1. Sumeet.Varma
  2. rajat1603
  3. xorfire
  4. memset123
  5. rekt_n00b
  6. akulsareen
  7. shubham1694
  8. alecsyde
  9. AnonymousBunny
  10. ajinkya1p3
  11. mohitbindal
  12. wittyskull
  13. ramesh.aggarwal
  14. ajs97
  15. polingy

UPD3: Editorial (The Remaining editorials will be updated very soon!)

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By KAN, 4 days ago, In English,


The Codeforces Round #398 (Div. 2) is going to be held on Saturday, 18 February 2017 at 9:05 UTC for participants from division 2.

The round is based on XIII Nizhny Novgorod Olympiad in Informatics for high school students named after V. D. Lelyukh, which will take place on Saturday in Nizhny Novgorod. However, not all problems from the Olympiad are included into this round.

The problems were prepared by KAP, ashmelev, ZhNV, kuzmichev_dima, mmatrosov, mike_live, arsor and me.

You will be given two hours to solve five problems. As usual, participants from division 1 can take part out of competition.

Scoring: 500-1250-1500-2000-2500.

UPD: The contest is over, thanks to all who has participated! Congratulations to the winners:

Div. 2:

  1. maryanna2015
  2. imperishableshooting
  3. aquatic
  4. Cth1999
  5. mister_dudec
  6. FallDream
  7. Illidan
  8. Alex342
  9. A.Magdy7 and TmEnd

Div. 1:

  1. eddy1021
  2. HellKitsune
  3. I_love_Tanya_Romanova
  4. gritukan
  5. latte0119

I apologise for the problem difficulty of the problem B, we expected much more accepteds. Hope you liked the problems! The editorial will be posted in 1.5 hours after the Olympiad is finished. Editorial.

We know about the issue with ratings, they will be rolled back and then updated properly. Don't worry.

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By KAN, 7 days ago, In English,

Hi Codeforces!

The Codeforces Round #397 by Kaspersky Lab and Barcelona Bootcamp (Div. 1 + Div. 2 combined) is going to be held tomorrow at 8:05 UTC!

This round is organized in collaboration with Hello Barcelona ACM ICPC Bootcamp 2017 and supported by Kaspersky Lab.

Over 100 students from 17 countries and more than 25 universities such as Cornell University, University College London, École Normale Supérieure, University of Tokyo, Saint-Petersburg State University and Moscow Institute of Physics and Technology gathered in Barcelona to train together for the ACM ICPC Finals.

For eight days students have been solving problems, listening to lectures, learning and making new friends. The training schedule is intense consisting of full-length practice contests, interleaved with one-day educational modules on topics we find especially important. Every contest is followed by an in-depth explanations of every problem and technique encountered in all forms.

It is hard to convey the atmosphere of the event in words. It is said, a picture is worth a thousand words and here is a selection to give you some idea of this fantastic bootcamp. You can see more pictures from the event here and here.

The round authors are Endagorion, ifsmirnov, zemen and Arterm. The round is combined for both divisions, will contain seven problems and last for three hours. Good luck!

UPD: The scoring is 500-1000-1250-2000-2500-3250-3500.

The contest is finished. We hope that you enjoyed it. Congratulations to the winners!

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By mahmoudbadawy, history, 2 weeks ago, In English,

Hello Codeforces!

I'm glad to announce that on Feb/07/2017 17:05 UTC Codeforces Round #396 for the second division will take place. As usual, First division participants can take part out of competition.

This round was prepared by me and mohammedehab2002.

I'd like to thank moaz123 for helping us prepare the round, zoooma13 for testing some problems, KAN for helping us in contest preparation and for translating the statements into Russian and MikeMirzayanov for the great Codeforces and Polygon platforms.

You will be given 5 problems and 2 hours to solve them.

The scoring distribution will be announced later.

UPD 500-1000-1500-2000-2500

UPD editorial is ready

UPD Congratulations to the winners!


  1. Verstand

  2. sd0061

  3. rajat1603

  4. gritukan

  5. ulna


  1. Verstand

  2. zhfs_ga_pitona

  3. zelta

  4. AomeII

  5. bciobanu

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By platypus179, history, 3 weeks ago, translation, In English,

Ladies and gentlemen!

Codeforces Round #395 for both divisions will happen tomorrow, on Thursday, 2 February 2017 at 13:35 UTC.

Problems were prepared by me (Vasiliy Alferov) and students of Moscow school #179: s17b2_voroneckij (Dima Voronetsky), ilya_the_lamer (Ilya Pauzner) and akvasha (Anton Kvasha). Also, KAN (Nikolay Kalinin) is author of one of the problems.

Invaluable help was given to us by Codeforces coordinator KAN (Nikolay Kalinin). Thanks to MikeMirzayanov (Mike Mirzayanov) for wonderful platforms Codeforces and Polygon. Also thanks to Endagorion (Mikhail Tikhomirov), winger (Vladislav Isenbaev), AlexFetisov (Alex Fetisov) and cdkrot (Dmitry Sayutin) for reading out our statements and testing the round.

Participants will be given five problems in both divisions. Some of the problems will be common for both divisions. The scoring distribution will be announced later.

Good luck to all!

UPD: Scoring distribution:

Div1: 500-750-1500-2000-2500

Div2: 500-1000-1500-1750-2500

UPD2: The contest is over. Hope you enjoyed the problems :)

UPD3: Congratulations to the winners!

Div 1:

  1. moejy0viiiiiv

  2. V--o_o--V

  3. fjzzq2002

  4. SkyDec

  5. uwi

  6. Belonogov

  7. aid

  8. dreamoon

  9. Um_nik

  10. Andrei1998

and Div 2:

  1. ljh2000

  2. MashiroSky

  3. sqcszboyi

  4. _Reborn_

  5. Factorio

  6. Dirak

  7. lnjlnj

  8. Manchery

  9. SarvagyaAgarwal

  10. mik

The editorial will be posted very soon.

UPD5: Editorial

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By Vladik, 3 weeks ago, translation, In English,

Hi there!

Codeforces round #394 for the second division will take place at the time of Tuesday, 31 January 17:35 MSK. Participants from the first division can compete out of competition. Contestants will have 2 hours and 6 problems to solve.

  • Problems were developed by me (Vladislav Vishnevki) and Denis Anischenko (altruist).
  • Alexey Vistyazh (netman) helped us as a contest coordinator.
  • Aliaksandr Drapko (sdryapko) and Alena Yaros were reading the statements carefully.
  • Vlad Khala (hapooo) tested the round.
  • Olya Yakovchik drew amazing illustrations for the problems.
  • Yuri Shilyaev (hloya_ygrt) translated editorials and round announcement for you.
  • And of course the round couldn't happen without (MikeMirzayanov), the author of platform polygon and codeforces, and also author of the idea to one of our problems.

Thanks everyone listed for the contribution you made to the contest preparation!

The main character of the legends is tiger Dasha, which loves to solve puzzles and make origami figures.

Good luck everyone! :)

UPD Round will consist of 6 problems.

UPD 500-1000-1500-2000-2500-3000

UPD Contest finished. It was decided to make round unrated, because codeforces is unstable now. I am really sad about that :( I hope everyone found a problem he liked. Editorial will be posted soon.

UPD Top 10 participants from second division: 1. mitterr
2. wh2000
3. Inhibitor
4. Border_Collie
5. HanwhaEagles
6. Vergara
7. zelta
8. GGOSinon
9. X-tazy
10. tonykky

Top 10 participants from first division: 1. eddy1021
2. Myungwoo
3. dreamoon
4. natsugiri
5. Shik

Congratulations to the winners!

UPD Editorial.

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By HellKitsune, history, 4 weeks ago, translation, In English,


After a long break, on Jan 25, 17:35 MSK will be held Educational Codeforces Round 17.

You will be given 6 tasks and 2 hours to solve them. The problemset, in my opinion, turned out to be well balanced and should be interesting for both novices and experienced participants. Task F may end up beneficial for many reds :)

The ideas for problems are by MikeMirzayanov and me. Thanks to fcspartakm for helping in preparation of this round.

I hope you will enjoy the problems and good luck!

UPD: The contest is over. Probably a little bit on the hard side for the beginners? Sorry! Editorial will be in the form of hints and will appear shortly.

UPD2: Editorial

UPD3: Challenge phase is over! Congratulations to winners:

  1. eddy1021
  2. W4yneb0t
  3. kmjp
  4. LHiC
  5. Narenji58

Also, top hackers!

  1. halyavin +249 : -35
  2. step_by_step +82 : -11
  3. -Morass- +51 : -141
  4. MishaPrigara +50 : -5
  5. uwi +46 : -9

If you want to share your ideas about tasks for next Educational Rounds, you can use the new problem proposal form. Please, use prefix "er-" in the name of the task so that we know that it is for Educational Rounds.

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By KAN, 4 weeks ago, In English,

Hi all,

The 8VC Venture Cup 2017 - Final Round is tommorrow at 18:05 UTC. Along with that, Codeforces Round #393 will be held at the same time both for Div. 1 and Div. 2 participants. The Div. 1 Edition will contain the same problems as the Final Round, the Div. 2 Edition will be easier.

Of course, those who have placed in top 200 in 8VC Venture Cup 2017 - Elimination Round should register for the Final Round, all the others should register for Div. 1 or Div. 2 editions according to their rating. All three contests will contain six problems, last two hours and be rated.

The problem authors are Um_nik, Endagorion, Umqra, pashka and me. Also huge thanks to fcspartakm for his help in preparation, and to vepifanov and AlexFetisov for testing the round. I suggest you reading all the problems to find which one you like the most!

I'd like to remind you about the prizes:

  • Overall 1st place — $2000
  • Overall 2nd place — $1000
  • Overall 3rd-5th places — $500 each
  • Overall 1-50th place — t-shirts with 8VC and company logos
  • Local Winner — Dinner with Joe Lonsdale (founder of Palantir, Addepar and 8VC) and other Silicon Valley technologists
  • Local top finishers — Opportunity to meet with leadership from 8VC portfolio companies

Please welcome one more company became interested in the Venture Cup, Progressly!

Progressly is a cloud-based Operational Performance Management platform allows you to document, collaborate on, and gain contextual insights into core business processes and outcomes in real time.

The scoring is usual in all three contests: 500-1000-1500-2000-2500-3000.

Congratulations to the winners!

8VC Vecture Cup 2017 winners:

  1. V--o_o--V
  2. bmerry
  3. Marcin_smu
  4. LHiC
  5. qwerty787788

Codeforces Round #393 Div. 1 winners:

  1. cubelover
  2. RomaWhite
  3. PavelKunyavskiy
  4. snuke
  5. gritukan

Codeforces Round #393 Div. 2 winners:

  1. Kacey
  2. wcx5tq957i
  3. Bekzhan.Kassenov
  4. Tailz
  5. ETA-Mu


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By Kniaz, 5 weeks ago, translation, In English,

Hello everybody!

I am glad to announce that at 19 January 2017 18:05 MSK will take place Codeforces Round #392 for participants of Div.2. Participants from the Div.1 may participate out of the competition as usual.

You will be offered 6 problems and 2 hours for solving them.

Great thanks to Nikolay Kalinin (KAN) and Alexey Vistyazh (netman) for their help with the contest preparation, Tatiana Semenova (Tatiana_S) for translating the statements and Mike Mirzayanov (MikeMirzayanov) for the Codeforces and Polygon systems and also for help with ideas of some problems and their preparation.

It's my second round and I hope that you like it more than the previous one. Fair rating to everyone!

UPD: Scoring 500 — 1000 — 1500 — 1750 — 2500 — 3000.

UPD: Editorial!!! I want to thank Mikhail Piklyaev (PikMike) and Tatiana Semenova (Tatiana_S) for translation of tutorial!

Congrats to the winners!

Div. 2

I wolf29

II alexwice

III WhyamIhere

4 TaTaPiH

5 Life_chicken

6 RewriteHarvestFesta

7 D0zingBear

8 whzzt

9 _Lucas97

10 Clayton

Div. 1

I W4yneb0t

II sd0061

III irkstepanov

4 wolf29

5 I_love_Tanya_Romanova

6 HellKitsune

7 kraskevich

8 kmjp

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