Hello Codeforces!

Hello Codeforces! As we wrap up another exciting round of our Kotlin Heroes series, it’s time to celebrate the champions who navigated the challenges like pros. With high stakes and impressive typing speeds, we witnessed incredible talent. Join us as we highlight the winners!

The top three contestants:

1. arvindf232
2. tourist
3. Golovanov399

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

These participants also won branded T-shirts:

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

It's great to see new people learning Kotlin and performing brilliantly in the competition. Challenges from all eleven previous rounds are available for practice here: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6, Episode 7, Episode 8, Episode 9, Episode 10 and Episode 11.

For those who would like to get to know Kotlin better, take a look at Basic Kotlin (solve Koans), Kotlin Playground, this competitive programming tutorial, and these videos on competitive programming in Kotlin.

We wish you luck and hope you enjoy Kotlin!

Hello Codeforces!

We've already had ten great rounds – how cool is that? We are pleased to congratulate the real heroes of Kotlin, who won prizes this time.

The top three contestants:

1. arvindf232
2. tourist
3. Golovanov399

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

These participants also won branded T-shirts:

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

It's great to see new people learn Kotlin and perform brilliantly in the competition. Challenges from all nine previous rounds are available for practice here: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6, Episode 7, Episode 8 and Episode 9.

For those who would like to get to know Kotlin better, take a look at Basic Kotlin (solve Koans), Kotlin Playground, this competitive programming tutorial, and these videos on competitive programming in Kotlin.

We wish you luck and hope you enjoy Kotlin!

Hello Codeforces!

We’re absolutely thrilled about the return of the Kotlin Heroes series! Judging by the record-setting number of registrations for Kotlin Heroes: Episode 9, we’re guessing you’ve missed this series as well.

It's great to see new people just getting started with Kotlin already performing well in competitions. The solutions to all eight previous rounds are available for practice purposes here: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6, Episode 7 and Episode 8

Congratulations to the top three contestants:

• tourist
• arvindf232
• Tlatoani

A Kotlin Heroes T-shirt and exclusive Kotlin stickers will be awarded to:

These participants have also won branded T-shirts:

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

For those who would like to get to know Kotlin better, we invite you to review our Kotlin solutions for the Advent of Code algorithmic puzzles, read our competitive programming tutorial, and watch the videos from our Kotlin in Competitive Programming YouTube playlist.

Good luck and we hope you enjoy Kotlin!

Hello Codeforces!

Kotlin Heroes: Episode 8 was the third round of the Kotlin Heroes series in 2021. The “8” from “Kotlin Heroes: Episode 8” symbolizes our infinite respect for all who participated! We are very happy to see new people learn Kotlin and perform brilliantly in the competition. All the previous rounds are available to be used for practice here: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6, and Episode 7.

Сongratulations to the top three contestants:

• SpyCheese
• Sugar_fan
• eatmore

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

These participants also won branded t-shirts:

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

The Kotlin Heroes: Episode 8 practice round took place during the ICPC World Finals. Gennady “tourist” Korotkevich, a repeat winner of Kotlin Heroes, was solving the practice round tasks during the event opening. We invite you to watch this presentation.

For those who would like to get to know Kotlin better, we invite you to check out Kotlin Basics track on JetBrains Academy, take a look at basic Kotlin, solve Koans in the free course from JetBrains Educational Products, visit Kotlin Playground, check out the tutorial, and these videos on competitive programming in Kotlin.

More information about Kotlin Heroes contests: https://kotlinlang.org/lp/kotlin-heroes/.

We wish you luck and hope you enjoy Kotlin!

Hello Codeforces!

The second round of the Kotlin Heroes series in 2021 was a great one! Thanks to the authors and all who participated! We are very happy to see new people among the winners. All the rounds are available to be used for practice here: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6 and Episode 7.

The “7” from “Kotlin Heroes: Episode 7” was the lucky number for this top three contestants:

1. Petr
2. tourist
3. Maksim1744

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

1. Petr
2. tourist
3. Maksim1744
4. Tlatoani
5. Golovanov399
6. Bench0310
7. Potassium
8. eatmore
9. tabr
10. SYury
11. LeoPro
12. Ra16bit
13. Jatana
14. nuip
15. xiaowuc1
16. Fortin
17. pashka
18. Geothermal
19. timmyfeng
20. senjougaharin
21. PurpleCrayon
22. TadijaSebez
23. natsugiri
24. uwi
25. Spheniscine
26. firi.
27. ngfam
28. TripleM5da
29. receed
30. MagentaCobra
31. WiwiHo
32. galen_colin
33. darkkcyan
34. Heart_Blue
35. DANDROZAVR
36. JettyOller
37. Kude
38. thenymphsofdelphi
39. SecondThread
40. qpwoeirut
41. Andreasyan
42. taran_1407
43. Moririn2528
44. insert_cool_handle
45. Sugar_fan
46. Dart-Xeyter
47. clyring
48. abc864197532
49. Skypiea
50. golikovnik

These participants also won branded t-shirts:

1. post
2. tongtongac
3. Roll_Num_56
4. jakao
5. Dmitry07
6. MarekSuchanek
7. Meliodas
8. litesam
9. Reeman
10. sashamc
11. eanacra
12. gustason
13. zuevmaxim
14. kadhonn
15. dayanruben
16. zubra.bubra
17. I_love_Avicii
18. bsav157
19. EgorkA_82
20. ZergTricky
21. rohitkumar0510
22. a1000
23. blakelist
24. fuad720
25. Tarun_19
26. vividsky
27. toilavu
28. codeash14
29. TheIceKing
30. stlouee
31. Neitex
32. pkpawan
33. GkG
34. denis2010
35. ramint
36. NooB_NO_1
37. ivanilos
38. ved_07
39. justaperson.
40. janicekartika
41. somerandomaltacc3034
42. solvemproblr
43. sigrlinn
44. godavari9823
45. vladas88
46. HanaYukii
47. alien_hun
48. HeNeos
49. nhanquyentran1
50. leekc

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

For those who would like to get to know Kotlin better, we invite you to take a look at basic Kotlin, solve Koans in the free course from JetBrains Educational Products, visit Kotlin Playground, check out the tutorial, and these videos on competitive programming in Kotlin.

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

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. JettyOller
10. Maksim1744
11. pashka
12. Sugar_fan
13. dalt
14. galen_colin
15. tabr
16. SYury
17. natsugiri
18. Golovanov399
19. Spheniscine
20. taran_1407
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. -14
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. sohsoh
30. igla
31. ans_human
32. mystic777
33. __RANI
34. CM_when
35. MissNick
36. MrArpit
37. penad
38. XAXAEBATb
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://mirror.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!

Hello Codeforces!

One of the most memorable Kotlin rounds of this year took place just recently. More than 6.7 thousand participants have registered for it. We thank everyone for your interest in Kotlin! Everyone who took part in this round will receive a link to download a personalized online certificate within the next two weeks. Work on this has already started.

Our warm congratulations to the winners of the 1st, 2nd, and 3rd place, who receive cash prizes:

1. tourist
2. Benq
3. Geothermal

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

And also these participants won branded T-shirts:

Finally, the last, but not least, gift for today: 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).

And a special recognition prize from the ICPC goes to tourist.

If you are still new to Kotlin you could look into a tutorial on competitive programming in Kotlin and watch these videos on competitive programming in Kotlin. Also, all the previous Kotlin Heroes Rounds are available for practice here: Episode 1, Episode 2, Episode 3, Episode 4 and Episode 5: ICPC Round.

We wish you all the best and hope you enjoy Kotlin.

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 and second Kotlin Heroes competitions which was held previously. Congratulations to the top 3 winners:

Episode 1

1. Petr
2. ecnerwala
3. eatmore

Episode 2

1. tourist
2. eatmore
3. Benq

Ready to challenge yourself to do better? The third "Kotlin Heroes" competition will be hosted on the Codeforces platform on Feb/27/2020 16:35 (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 badge, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

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

• The round is unrated.
• The contest will have 6-10 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.

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

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.

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 Kotlin Heroes competition which was held back in May. Congratulations to the top 3 winners Petr, ecnerwala, and eatmore on their incredible achievement, especially considering they were up against 4,500 other registrants from over 63 countries. We’d also like to give a shout out to tourist for being the only other person, outside of the top 3, to manage to solve every problem set from this round. Well done all of you!

Ready to challenge yourself to do better? The second "Kotlin Heroes" competition will be hosted on the Codeforces platform on the 7th of September, 2019, at 14:35 UTC (17:35 MSK, 07:35 PDT, 22:35 CST). 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 badge, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

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

• The round is unrated.
• The contest will have 6-10 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.

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

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: Thank you for the participation. The editorials are published.

Hello, Codeforces!

We are happy to announce that in partnership with Codeforces to promote Kotlin programming language we are launching a series of "Kotlin Heroes" programming contests.

Kotlin programming language was introduced by JetBrains in 2011 and reached its first stable version 1.0 in 2016. The current language version is 1.3.31. The language is focused on solving the needs of application developers in various domains. Kotlin is a statically typed language that is designed for writing concise code, with less ceremony and more substance in it, and to scale from applications of just a few lines long to multi-million-lines projects.

While not being specifically designed for competitive programming, it incidentally fits well in this domain, reducing the typical amount boilerplate that a programmer needs to write and read while working with the code almost to the level offered by dynamically-typed scripting languages, while having tooling and performance of a statically-typed language.

The first "Kotlin Heroes" competition will be hosted at Codeforces platform on May/28/2019 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 badge, competitors solving at least one problem will enter into a draw for one of 50 Kotlin Heroes t-shirts.

The round is held in accordance with slightly modified ICPC rules:

• The round is unrated.
• The contest will have 6-10 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).

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

To help you get familiar with 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 solutions are open, it means that you can look at a solution even if you haven't solved a problem yet. The practice round is available by the link.

We wish you luck and hope you enjoy Kotlin.

UPD 1: Many thanks to the testers elizarov, Benq, cdkrot, nhho, ksun48. Also KAN helped a lot with suggestions to the problems. And to all the participants warm greetings from authors MikeMirzayanov, vovuh, adedalic and pashka — they invented and prepared the problems for you!