BledDest's blog

By BledDest, 3 months ago, In English

Given the current circumstances, we have decided to postpone Kotlin Heroes until further notice. Thank you for your understanding.

Hello, Codeforces!

First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the eight Kotlin Heroes competitions which were held previously: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6, Episode 7, and Episode 8.

Ready to challenge yourself to do better? The [contest:1643] competition will be hosted on the Codeforces platform on [contest_time:1643]. The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers.

Prizes:

Top three winners will get prizes of $512, $256, and $128 respectively, top 50 will win a Kotlin Heroes t-shirt and an exclusive Kotlin sticker, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

Registration is already open and available via the link. It will be available until the end of the round.

The round will again be held in accordance with a set of slightly modified ICPC rules:

  • The round is unrated.
  • The contest will have 9 or 10 problems of various levels of complexity.
  • You are only allowed to use Kotlin to solve these problems.
  • Participants are ranked according to the number of correctly solved problems. Ties are resolved based on the lowest total penalty time for all problems, which is computed as follows. For each solved problem, a penalty is set to the submission time of that problem (the time since the start of the contest). An extra penalty of 10 minutes is added for each failed submission on solved problems (i. e., if you never solve the problem, you will not be penalized for trying that problem). If two participants solved the same number of problems and scored the same penalty, then those of them who had previously made the last successful submission will be given an advantage in the distribution of prizes and gifts.

REGISTER →

If you are still new to Kotlin we have prepared a tutorial on competitive programming in Kotlin and Kotlin Heroes: Practice 9, where you can try to solve a few simple problems in Kotlin. The practice round is available by the link.

We made an announcement about the Kotlin Heroes: Episode 9 practice stream, but unfortunately we had to cancel it. Sorry for the inconvenience!

We wish you luck and hope you enjoy Kotlin.

Read more »

Announcement of Kotlin Heroes: Practice 9
 
 
 
 
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By BledDest, 4 months ago, In English

1633A - Div. 7

Idea: BledDest, preparation: BledDest

Tutorial
Solution (BledDest)

1633B - Minority

Idea: BledDest, preparation: awoo and Neon

Tutorial
Solution (awoo)

1633C - Kill the Monster

Idea: BledDest, preparation: Neon

Tutorial
Solution (awoo)

1633D - Make Them Equal

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

1633E - Spanning Tree Queries

Idea: BledDest, preparation: awoo

Tutorial
Solution (awoo)

1633F - Perfect Matching

Idea: BledDest, preparation: BledDest

Tutorial
Solution (BledDest)

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By BledDest, 5 months ago, In English

1618A - Polycarp and Sums of Subsequences

Idea: Brovko, preparation: Brovko

Tutorial
Solution (Brovko)

1618B - Missing Bigram

Idea: BledDest, preparation: awoo

Tutorial
Solution (awoo)

1618C - Paint the Array

Idea: BledDest, preparation: BledDest

Tutorial
Solution (BledDest)

1618D - Array and Operations

Idea: BledDest, preparation: BledDest

Tutorial
Solution (BledDest)

1618E - Singers' Tour

Idea: shnirelman, preparation: shnirelman

Tutorial
Solution (shnirelman)

1618F - Reverse

Idea: Lankin, preparation: Lankin

Tutorial
Solution (awoo)
Solution (BledDest)

1618G - Trader Problem

Idea: BledDest, preparation: BledDest

Tutorial
Solution (awoo)
Solution (BledDest)

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By BledDest, 5 months ago, translation, In English

Hello, Codeforces!

On Dec/14/2021 17:35 (Moscow time) the Codeforces Round #760 (Div. 3) will start. This is a usual round for the participants from the third division. The round will contain 8 problems, which are mostly suited for participants with rating below 1600 (or we hope so). Although, as usual, participants with rating of 1600 and greater can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ACM-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 (we hope that our tests are strong enough, so there won't be too many solutions hacked during this phase).

You will have to solve 8 problems in 2 hours and 15 minutes. The penalty for a wrong submission is equal to 10 minutes.

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

  • take part in at least two rated rounds (and solve at least one problem in each of them),
  • 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 were prepared by Brovko, shnirelman, Lankin, awoo and me. We would like to thank the testers of the round: vovuh, Nil_Sinyaev, IsaacMoris, altynai, MarcosK, soyaa, ZulaMostafa, Omar.Yasser, mumumucoder, peroon and kocko.

And, the last but not the least, thanks to Mike MikeMirzayanov Mirzayanov for Codeforces and Polygon systems!

Good luck in the contest! I hope you'll enjoy solving the problems we have prepared.

UPD: The editorial is out.

Read more »

 
 
 
 
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By BledDest, 6 months ago, translation, In English

1612A - Distance

Idea: BledDest, preparation: BledDest

Tutorial
Solution (BledDest)

1612B - Special Permutation

Idea: MikeMirzayanov, preparation: MikeMirzayanov

Tutorial
Solution (BledDest)

1612C - Chat Ban

Idea: vovuh, preparation: vovuh

Tutorial
Solution (vovuh)

1612D - X-Magic Pair

Idea: vovuh, preparation: vovuh

Tutorial
Solution (vovuh)

1612E - Messages

Idea: BledDest, preparation: BledDest

Tutorial
Solution (BledDest)

1612F - Armor and Weapons

Idea: BledDest, preparation: BledDest

Tutorial
Solution (BledDest)

1612G - Max Sum Array

Idea: adedalic, preparation: adedalic

Tutorial
Solution (adedalic)

Read more »

 
 
 
 
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By BledDest, 7 months ago, In English

Hello Codeforces!

On Oct/10/2021 12:05 (Moscow time) Educational Codeforces Round 115 (Rated for Div. 2) will start. Note that the start time is unusual.

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 Alex fcspartakm Frolov, Mikhail awoo Piklyaev, Max 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:

Hello once again, Codeforces!

We are thrilled to congratulate our faculty member Nikolay KAN Kalinin on his first place at the ICPC World Finals, celebrated in Moscow, Russia. Years of training by Nikolai and his team from Nizhny Novgorod State University lead them to the top of the scoreboard, defeating teams from 116 other universities and becoming world champions.

We would also like to congratulate our future student Egor mhq Dubovik, who won the silver medal with the Belarusian State University. Egor will join our Masters in Computer Science in the coming weeks.

We are looking forward to seeing Nikolay again next January when he teaches his course on Advanced Algorithms and Data Structures alongside Mike Mirzayanov. In this course, students focus on key and in-depth algorithms and data structures that form a modern computer specialist’s toolkit.

We are always excited to see Codeforces participants as our students here at Harbour.Space, so once again we’ve given a special discount (up to 70%) for the single course participation in Barcelona, Spain (travel cost and accommodation are not included).

Reserve your spot →

Codeforces and Harbour.Space

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

Harbour.Space University

UPD: The editorial can be found here.

Read more »

 
 
 
 
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By BledDest, 7 months ago, In English

First of all, I would like to thank all testers of the round: pashka, FlakeLCR, peti1234, Akulyat, bugdone, pacha2880. Also huge thanks to co-authors of the contest: Neon, adedalic and awoo.

I hope you enjoyed participating in the round!

Okay, now for the editorial itself:

1571A - Sequence of Comparisons

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

1571B - Epic Novel

Idea: BledDest, preparation: adedalic

Tutorial
Solution (adedalic)

1571C - Rhyme

Idea: BledDest, preparation: adedalic

Tutorial
Solution (adedalic)

1571D - Sweepstake

Idea: BledDest, preparation: adedalic

Tutorial
Solution (adedalic)

1571E - Fix the String

Idea: BledDest, preparation: Neon

Tutorial
Solution (pashka)

1571F - Kotlinforces

Idea: BledDest, preparation: BledDest

Tutorial
Solution (pashka)

1571G - A Battle Against a Dragon

Idea: BledDest, preparation: awoo

Tutorial
Solution (awoo)

1571H - Laser Beams

Idea: BledDest, preparation: BledDest

Tutorial
Solution (pashka)

1571I - Physical Examination

Idea: BledDest, preparation: awoo

Tutorial
Solution (awoo)

1571J - Two Railroads

Idea: BledDest, preparation: BledDest

Tutorial
Solution (pashka)

Read more »

 
 
 
 
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By BledDest, 8 months ago, In English

Hello, Codeforces!

First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the seven Kotlin Heroes competitions which were held previously: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6, and Episode 7.

Ready to challenge yourself to do better? The Kotlin Heroes: Episode 8 competition will be hosted on the Codeforces platform on Oct/07/2021 17:35 (Moscow time). The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers.

Prizes:

Top three winners will get prizes of $512, $256, and $128 respectively, top 50 will win a Kotlin Heroes t-shirt and an exclusive Kotlin sticker, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

Registration is already open and available via the link. It will be available until the end of the round.

The round will again be held in accordance with a set of slightly modified ICPC rules:

  • The round is unrated.
  • The contest will have 10 problems of various levels of complexity.
  • You are only allowed to use Kotlin to solve these problems.
  • Participants are ranked according to the number of correctly solved problems. Ties are resolved based on the lowest total penalty time for all problems, which is computed as follows. For each solved problem, a penalty is set to the submission time of that problem (the time since the start of the contest). An extra penalty of 10 minutes is added for each failed submission on solved problems (i. e., if you never solve the problem, you will not be penalized for trying that problem). If two participants solved the same number of problems and scored the same penalty, then those of them who had previously made the last successful submission will be given an advantage in the distribution of prizes and gifts.

REGISTER →

If you are still new to Kotlin we have prepared a tutorial on competitive programming in Kotlin and Kotlin Heroes: Practice 8, where you can try to solve a few simple problems in Kotlin. The practice round is available by the link.

And last but not the least: two-time ICPC World Champion and winner of four previous Kotlin Heroes episodes Gennady tourist Korotkevich will be featured in a livecoding session, conducted by JetBrains, where he is going to show how to solve the problems from the Practice round, so you can learn how to use Kotlin in contests from the most famous competitive programmer in the world. The JetBrains Presentation and livecoding session from Gennady will be streamed on ICPC Live and Kotlin YouTube channel. The stream starts at 10 a. m. on the 2nd of October, Moscow time (UTC+3), you can join the stream by the link.

We wish you luck and hope you enjoy Kotlin.

Read more »

Announcement of Kotlin Heroes: Practice 8
Announcement of Kotlin Heroes: Episode 8
 
 
 
 
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By BledDest, 11 months ago, In English

First of all, I would like to thank all testers of the round: PavelKunyavskiy, IlyaLos, Vladik, I_Remember_Olya_ashmelev, nooinenoojno, AlexFetisov. Also huge thanks to co-authors of the contest: Neon, vovuh and awoo.

I hope you enjoyed participating in the round!

Okay, now for the editorial itself:

1533A - Travel to Bertown

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

1533B - Nearest Point Function

Idea: BledDest, preparation: vovuh

Tutorial
Solution (vovuh)

1533C - Sweets

Idea: Neon, preparation: Neon

Tutorial
Solution (Neon)

1533D - String Searching

Idea: BledDest and Neon, preparation: Neon

Tutorial
Solution (Neon)

1533E - Chess Team Forming

Idea: BledDest, preparation: awoo

Tutorial
Solution (awoo)

1533F - Binary String Partition

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

1533G - Biome Map

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

1533H - Submatrices

Idea: Neon, preparation: Neon

Tutorial
Solution (Neon)

1533I - Excursions

Idea: BledDest, preparation: BledDest

Tutorial
Solution (Neon)

1533J - Pawns

Idea: BledDest, preparation: BledDest

Tutorial
Solution (Neon)

Read more »

 
 
 
 
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By BledDest, 11 months ago, In English

Hello, Codeforces!

First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the five Kotlin Heroes competitions which were held previously: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, and Episode 6.

Ready to challenge yourself to do better? The Kotlin Heroes: Episode 7 competition will be hosted on the Codeforces platform on Jun/29/2021 17:35 (Moscow time). The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers.

Prizes:

Top three winners will get prizes of $512, $256, and $128 respectively, top 50 will win a Kotlin Heroes t-shirt and an exclusive Kotlin sticker, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

Registration is already open and available via the link. It will be available until the end of the round.

The round will again be held in accordance with a set of slightly modified ICPC rules:

  • The round is unrated.
  • The contest will have 9 problems of various levels of complexity.
  • You are only allowed to use Kotlin to solve these problems.
  • Participants are ranked according to the number of correctly solved problems. Ties are resolved based on the lowest total penalty time for all problems, which is computed as follows. For each solved problem, a penalty is set to the submission time of that problem (the time since the start of the contest). An extra penalty of 10 minutes is added for each failed submission on solved problems (i. e., if you never solve the problem, you will not be penalized for trying that problem). If two participants solved the same number of problems and scored the same penalty, then those of them who had previously made the last successful submission will be given an advantage in the distribution of prizes and gifts.

REGISTER →

If you are still new to Kotlin we have prepared a tutorial on competitive programming in Kotlin and Kotlin Heroes: Practice 7, where you can try to solve a few simple problems in Kotlin. The practice round is available by the link.

We wish you luck and hope you enjoy Kotlin.

Read more »

Announcement of Kotlin Heroes: Practice 7
Announcement of Kotlin Heroes: Episode 7
 
 
 
 
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By BledDest, history, 11 months ago, In English

1535A - Fair Playoff

Idea: BledDest

Tutorial
Solution (Neon)

1535B - Array Reodering

Idea: BledDest

Tutorial
Solution (Neon)

1535C - Unstable String

Idea: BledDest

Tutorial
Solution (Neon)

1535D - Playoff Tournament

Idea: BledDest

Tutorial
Solution (Neon)

1535E - Gold Transfer

Idea: adedalic

Tutorial
Solution (adedalic)

1535F - String Distance

Idea: BledDest

Tutorial
Solution (BledDest)

Read more »

 
 
 
 
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By BledDest, 12 months ago, In English

1525A - Potion-making

Idea: adedalic

Tutorial
Solution (adedalic)

1525B - Permutation Sort

Idea: BledDest

Tutorial
Solution (Neon)

1525C - Robot Collisions

Idea: BledDest

Tutorial
Solution (awoo)

1525D - Armchairs

Idea: BledDest

Tutorial
Solution (BledDest)

1525E - Assimilation IV

Idea: BledDest

Tutorial
Solution (adedalic)

1525F - Goblins And Gnomes

Idea: BledDest

Tutorial
Solution (BledDest)

Read more »

 
 
 
 
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By BledDest, history, 14 months ago, In English

First of all, I would like to thank all testers of the round: Um_nik, IlyaLos, Roms, nuipojaluista, Supermagzzz, Stepavly, hg333. Also huge thanks to co-authors of the contest: Neon, adedalic, vovuh and awoo.

I hope you enjoyed participating in the round!

Okay, now for the editorial itself:

1488A - From Zero To Y

Idea: BledDest, preparation: Neon

Tutorial

1488B - RBS Deletion

Idea: BledDest, preparation: BledDest

Tutorial

1488C - Two Policemen

Idea: vovuh, preparation: vovuh

Tutorial

1488D - Problemsolving Marathon

Idea: vovuh, preparation: awoo

Tutorial

1488E - Palindromic Doubles

Idea: BledDest, preparation: awoo

Tutorial

1488F - Dogecoin

Idea: BledDest and Neon, preparation: Neon

Tutorial

1488G - Painting Numbers

Idea: Neon, preparation: Neon

Tutorial

1488H - Build From Suffixes

Idea: BledDest, preparation: awoo

Tutorial

1488I - Demonic Invasion

Idea: BledDest, preparation: BledDest

Tutorial

1488J - Flower Shop

Idea: BledDest, preparation: Neon and adedalic

Tutorial

Read more »

 
 
 
 
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By BledDest, 14 months ago, In English

Hello, Codeforces!

First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the five Kotlin Heroes competitions which were held previously: Episode 1, Episode 2, Episode 3, Episode 4, and Episode 5: ICPC Round.

Ready to challenge yourself to do better? The Kotlin Heroes: Episode 6 competition will be hosted on the Codeforces platform on Mar/09/2021 17:35 (Moscow time). The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers.

Prizes:

Top three winners will get prizes of $512, $256, and $128 respectively, top 50 will win a Kotlin Heroes t-shirt and an exclusive Kotlin sticker, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

Registration is already open and available via the link. It will be available until the end of the round.

The round will again be held in accordance with a set of slightly modified ICPC rules:

  • The round is unrated.
  • The contest will have 9 problems of various levels of complexity.
  • You are only allowed to use Kotlin to solve these problems.
  • Participants are ranked according to the number of correctly solved problems. Ties are resolved based on the lowest total penalty time for all problems, which is computed as follows. For each solved problem, a penalty is set to the submission time of that problem (the time since the start of the contest). An extra penalty of 10 minutes is added for each failed submission on solved problems (i. e., if you never solve the problem, you will not be penalized for trying that problem). If two participants solved the same number of problems and scored the same penalty, then those of them who had previously made the last successful submission will be given an advantage in the distribution of prizes and gifts.

REGISTER →

If you are still new to Kotlin we have prepared a tutorial on competitive programming in Kotlin and Kotlin Heroes: Practice 6, where you can try to solve a few simple problems in Kotlin. The practice round is available by the link.

We wish you luck and hope you enjoy Kotlin.

Read more »

Announcement of Kotlin Heroes: Episode 6
Announcement of Kotlin Heroes: Practice 6
 
 
 
 
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By BledDest, 18 months ago, translation, In English

First of all, I would like to thank all testers of the round: elizarov, IlyaLos, nuipojaluista, hg333, nooinenoojno, winger, neko_nyaaaaaaaaaaaaaaaaa, kort0n, hos.lyric and Roms. Also huge thanks to co-authors of the contest: Neon, adedalic, vovuh and awoo.

I hope you enjoyed participating in the round!

Okay, now for the editorial itself:

1431A - Selling Hamburgers

Idea: BledDest, preparation: BledDest

Tutorial
Solution (elizarov)

1431B - Polycarp and the Language of Gods

Idea: BledDest, preparation: awoo

Tutorial
Solution (elizarov)

1431C - Black Friday

Idea: Neon, preparation: Neon and awoo

Tutorial
Solution (elizarov)

1431D - Used Markers

Idea: BledDest, preparation: adedalic

Tutorial
Solution (elizarov)

1431E - Chess Match

Idea: BledDest, preparation: BledDest

Tutorial
Solution (Ne0n25)

1431F - Neural Network Problem

Idea: vovuh, preparation: vovuh

Tutorial
Solution (vovuh)

1431G - Number Deletion Game

Idea: BledDest, preparation: BledDest

Tutorial
Solution (Ne0n25)

1431H - Rogue-like Game

Idea: BledDest, preparation: Neon

Tutorial
Solution (Ne0n25)

1431I - Cyclic Shifts

Idea: Neon, preparation: Neon

Tutorial
Solution (Ne0n25)

1431J - Zero-XOR Array

Idea: Neon, preparation: Neon and adedalic

Tutorial
Solution (Ne0n25)

Read more »

 
 
 
 
  • Vote: I like it
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By BledDest, history, 18 months ago, In English

Hello, Codeforces!

First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the first, second, third, and fourth Kotlin Heroes competitions which were held previously: Episode 1, Episode 2, Episode 3 and Episode 4.

Ready to challenge yourself to do better? The Kotlin Heroes 5: ICPC Round competition will be hosted on the Codeforces platform on Nov/12/2020 17:35 (Moscow time). The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers.

Prizes:

Top three winners will get prizes of $512, $256, and $128 respectively, top 50 will win a Kotlin Heroes t-shirt and an exclusive Kotlin sticker, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

Everyone who takes part in this round will get an electronic Participation Certificate.

There is also a special recognition prize from the ICPC: ICPC- experience, an invitation to the Moscow World Finals 2021, all-inclusive on-site (hotel, meals, ceremonies, and swag, are included; visa, flights, transportation to the contest location is not).

Registration is already open and available via the link. It will be available until the end of the round.

The round will again be held in accordance with a set of slightly modified ICPC rules:

  • The round is unrated.
  • The contest will have 9 problems of various levels of complexity.
  • You are only allowed to use Kotlin to solve these problems.
  • Participants are ranked according to the number of correctly solved problems. Ties are resolved based on the lowest total penalty time for all problems, which is computed as follows. For each solved problem, a penalty is set to the submission time of that problem (the time since the start of the contest). An extra penalty of 10 minutes is added for each failed submission on solved problems (i. e., if you never solve the problem, you will not be penalized for trying that problem). If two participants solved the same number of problems and scored the same penalty, then those of them who had previously made the last successful submission will be given an advantage in the distribution of prizes and gifts.

REGISTER →

If you are still new to Kotlin we have prepared a tutorial on competitive programming in Kotlin and Kotlin Heroes 5: ICPC Round (Practice), where you can try to solve a few simple problems in Kotlin. All the solutions are open, which means that you can look at the solution even if you haven't solved the problem yet. The practice round is available by the link.

We wish you luck and hope you enjoy Kotlin.

UPD: The editorial can be found here.

Read more »

Announcement of Kotlin Heroes 5: ICPC Round
 
 
 
 
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By BledDest, 19 months ago, In English

1430A - Number of Apartments

Idea: fcspartakm

Tutorial
Solution (fcspartakm)

1430B - Barrels

Idea: fcspartakm

Tutorial
Solution (fcspartakm)

1430C - Numbers on Whiteboard

Idea: BledDest

Tutorial
Solution (fcspartakm)

1430D - String Deletion

Idea: BledDest

Tutorial
Solution (BledDest)

1430E - String Reversal

Idea: fcspartakm

Tutorial
Solution (fcspartakm)

1430F - Realistic Gameplay

Idea: BledDest

Tutorial
Solution (adedalic)

1430G - Yet Another DAG Problem

Idea: BledDest

Tutorial
Solution (BledDest)

Read more »

 
 
 
 
  • Vote: I like it
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By BledDest, history, 19 months ago, translation, In English

Hello Codeforces!

On Oct/11/2020 12:05 (Moscow time) Educational Codeforces Round 96 (Rated for Div. 2) will start. Note that the start time is unusual.

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 Adilbek adedalic Dalabaev, Alex fcspartakm Frolov and me. Also huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Good luck to all the participants!

UPD: The editorial is here.

Congratulations to the winners:

Rank Competitor Problems Solved Penalty
1 WZYYN 7 186
2 137_345_2814 7 194
3 jiangly 7 200
4 LayCurse 7 203
5 dreamoon_love_AA 7 258

Congratulations to the best hackers:

Rank Competitor Hack Count
1 ViciousCoder 100:-9
2 ManasG 45:-13
3 Valera_Grinenko 57:-40
4 AhmadEbtihal 36:-3
5 fstzyh 38:-9

858 successful hacks and 2258 unsuccessful hacks were made in total!

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

Problem Competitor Penalty
A sevlll777 0:01
B jkchen 0:03
C alireza_kaviani 0:03
D jkchen 0:12
E MagicSpark 0:05
F LayCurse 0:36
G MagicSpark 0:36

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By BledDest, 2 years ago, In English

First of all, I would like to thank all of the testers: elizarov, darnley, IlyaLos, _overrated_, SergeyMelnikov, winger, FieryPhoenix, infinitepro, Sho, GrandDaddy, bfs.07, spookywooky. Also huge thanks to co-authors of the contest: MikeMirzayanov, Neon, Roms, adedalic, vovuh and awoo.

I hope you enjoyed participating in the round!

Okay, now for the editorial itself:

1346A - Color Revolution

Idea: BledDest, preparation: awoo

Tutorial
Solution (elizarov)

1346B - Boot Camp

Idea: BledDest, preparation: Neon

Tutorial
Solution (elizarov)

1346C - Spring Cleaning

Idea: vovuh, preparation: vovuh

Tutorial
Solution (elizarov)

1346D - Constructing the Dungeon

Idea: MikeMirzayanov, preparation: Neon

Tutorial
Solution (elizarov)

1346E - Magic Tricks

Idea: BledDest, preparation: Neon

Tutorial
Solution (elizarov)

1346F - Dune II: Battle For Arrakis

Idea: vovuh, preparation: vovuh

Tutorial
Solution (elizarov)

1346G - Two IP Cameras

Idea: adedalic, preparation: adedalic

Tutorial
Solution (elizarov)

1346H - Game with Segments

Idea: Roms, preparation: Roms

Tutorial
Solution (tourist)

1346I - Pac-Man 2.0

Idea: Neon and BledDest, preparation: Neon

Tutorial
Solution (Ne0n25)

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By BledDest, 2 years ago, In English

Hello, Codeforces!

First and foremost, we would like to say a massive thank you to everyone who entered and submitted their answers to the first, second and third Kotlin Heroes competitions which were held previously. Congratulations to the top 3 winners:

Episode 1

  1. Petr
  2. ecnerwala
  3. eatmore

Episode 2

  1. tourist
  2. eatmore
  3. Benq

Episode 3

  1. Egor
  2. tourist
  3. Benq

Ready to challenge yourself to do better? The fourth "Kotlin Heroes" competition will be hosted on the Codeforces platform on May/29/2020 17:35 (Moscow time). The contest will last 2 hours 30 minutes and will feature a set of problems from simple ones, designed to be solvable by anyone, to hard ones, to make it interesting for seasoned competitive programmers. Top three winners will get prizes of $512, $256, and $128 respectively, top 50 will win a Kotlin Heroes t-shirt and an exclusive Kotlin sticker, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

Registration is already open and available via the link. It will be available until the end of the round.

The round will again be held in accordance with a set of slightly modified ICPC rules:

  • The round is unrated.
  • The contest will have 9 problems of various levels of complexity.
  • You are only allowed to use Kotlin to solve these problems.
  • Participants are ranked according to the number of correctly solved problems. Ties are resolved based on the lowest total penalty time for all problems, which is computed as follows. For each solved problem, a penalty is set to the submission time of that problem (the time since the start of the contest). An extra penalty of 10 minutes is added for each failed submission on solved problems (i.e., if you never solve the problem, you will not be penalized for trying that problem). If two participants solved the same number of problems and scored the same penalty, then those of them who had previously made the last successful submission will be given an advantage in the distribution of prizes and gifts.

REGISTER →

If you are still new to Kotlin we have prepared a tutorial on competitive programming in Kotlin and a practice round, where you can try to solve a few simple problems in Kotlin. All the solutions are open, which means that you can look at the solution even if you haven't solved the problem yet. The practice round is available by the link.

We wish you luck and hope you enjoy Kotlin.

UPD: The editorial can be found here. Thank you for participation! I hope you enjoyed the problems.

Read more »

Announcement of Kotlin Heroes: Episode 4
Announcement of Kotlin Heroes: Practice 4
 
 
 
 
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By BledDest, history, 2 years ago, In English
Div2A
Div2B/Div1A
Div2C
Div2D/Div1B
Div2E/Div1C
Div2F/Div1D
Div1E
Div1F

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By BledDest, 2 years ago, translation, In English

Hello everybody!

Today, on March 1st, 2020 the final round of Technocup olympiad for Russian-speaking high school students is held. The round starts at 13:00 Moscow time.

For those who want to compete on the same problems, we will host two Codeforces rounds: one for the first, and one for the second division. The rounds will start at 13:05 UTC, don't miss them! The round will start just after the onsite contest ends, so it can be postponed slightly if the onsite event timetable changes.

If you compete in the Final Round today, you can't compete in the Codeforces round #625.

The problems are prepared by MikeMirzayanov, Endagorion, tourist, Roms, vovuh, voidmax, adamant and me. Many thanks to KAN, AndreySergunin, antontrygubO_o, kuviman, MrPaul_TUser, Stepavly, artsin666, Pavs, AdvancerMan, Stresshoover, Peinot, geranazavr555, defolaut, nuipojaluista, cannor147, PrianishnikovaRina and Pavlova for testing the problems!

P.S. Because of the onsite contest, some Codeforces features may be disabled today.

Good luck!

UPD: The editorial is here.

Congratulations to the winners of the round:

Div1

1) ksun48

2) maroonrk

3) jijiang

4) Radewoosh

5) Um_nik

Div2

1) DraqonLore

2) DishonoredRighteous

3) 99824485311011

4) endbringer

5) cml

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By BledDest, history, 2 years ago, translation, In English
Tutorial is loading...
Tutorial is loading...
Tutorial is loading...
Tutorial is loading...
Tutorial is loading...
Tutorial is loading...

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By BledDest, history, 2 years ago, translation, In English

Hello Codeforces!

Codeforces Round #608 (Div. 2) will be held on Dec/15/2019 12:15 (Moscow time). The round will be rated for Div. 2 contestants. There will be 6 problems for 2 hours. Please, notice that the start time is unusual.

The round will be rated for the participants with rating lower than 2100. The statements will be available in Russian and English.

The round coincides with (and is based on) a local Saratov's olympiad for high school students. That's why we ask the participants of the olympiad to stay silent and don't share the statements of the contest with anyone. Unfortunately, we cannot add all the problems to the round, it will contain only six problems.

The problems were proposed and prepared by Alexander fcspartakm Frolov, Adilbek adedalic Dalabaev, Vladimir vovuh Petrov and me.

We also would like to express our gratitude to Mike MikeMirzayanov Mirzayanov for the permission to make a mirror and Codeforces and Polygon platforms, to our coordinator Dmitry cdkrot Sayutin or his help with testing the problems and preparing the round, and to the team of testers: MrPaul_TUser, Stresshoover, Supermagzzz, artsin666, defolaut, Peinot, PrianishnikovaRina, nuipojaluista, Ivan19981305, lankin.i, Pavlova, Decibit, dmitrii.krasnihin, AlexSap, unreal.eugene.

Scoring distribution: 500 — 1000 — 1250 — 1750 — 2250 — 3000.

Good luck!

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By BledDest, 3 years ago, translation, In English

1215A - Yellow Cards

Editorial
Solution (fcspartakm)

1215B - The Number of Products

Editorial
Solution (fcspartakm)

1215C - Swap Letters

Editorial
Solution (fcspartakm)

1215D - Ticket Game

Editorial
Solution (fcspartakm)

1215E - Marbles

Editorial
Solution (fcspartakm)

1215F - Radio Stations

Editorial
Solution (BledDest)

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