BledDest's blog

Kotlin Heroes 13 Announcement
By BledDest, 8 months ago, In English

Greetings Codeforces!

Ready to put your Kotlin skills to the test? Kotlin Heroes is your playground: a chance to experiment with the language's features, tackle fun and challenging problems, and level up your programming abilities. Perfect for beginners and experts alike!

A massive shout-out to all the amazing coders who have competed in past Kotlin Heroes events: Episode 1, Episode 2, Episode 3, Episode 4, Episode 5: ICPC Round, Episode 6, Episode 7, Episode 8, Episode 9, Episode 10, Episode 11 and Episode 12.

Kotlin Heroes is a great way to play around with Kotlin’s features, learn something new, and practice using the language by solving fun problems. It is great for programmers of any level!

We invite you to join the practice round, where you can improve your algorithmic problem-solving skills and complete training problems. In this round, all the solutions are open, and you can request hints if you’re stuck.

Here are some things you can do to help you refresh your knowledge of Kotlin and learn more about competitive programming while you practice:

And if you’d like to see how the top competitive programmers approach these challenges, check out ecnerwala and SecondThread solving problems from this practice round live on stage at the ICPC World Finals in Baku.

Mark your calendars for September 12, 2025! Kotlin Heroes: Episode 13 offers 2 hours and 30 minutes of problem-solving, featuring a wide range of tasks designed for everyone, from those just starting out to experienced competitive programmers.

The use of AI-based tools during the main contest is strictly limited. To find out the guidelines for proper AI use, what is allowed and what is prohibited, please read the post "Rule Restricting the use of AI". Improper use of AI tools during the main contest may result in disqualification. Using automatic translation tools (including but not limited to neural networks and AI) to convert code written in other programming languages to Kotlin goes against the spirit of the competition, so it is also strictly prohibited.

REGISTER →

Prizes:

  • 🥇 $512 (or equivalent value) for 1st place
  • 🥈 $256 for 2nd place
  • 🥉 $128 for 3rd place
  • 👕 Kotlin Heroes T-shirts for the top 50 participants
  • 🎁 A raffle of 50 T-shirts for anyone who solves at least one problem

Please note that we are not able to ship prizes to any country, state, province, or territory subject to comprehensive OFAC sanctions, including Belarus, Cuba, Iran, North Korea, Russia, Syria, or the Crimea, Donetsk, or Luhansk regions. For complete the list, please visit this page.

Best of luck to everyone!

upd: Editorial can be found here.

Announcement of Kotlin Heroes: Episode 13
Announcement of Kotlin Heroes: Practice 13
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8 months ago, hide # |
 
Vote: I like it +3 Vote: I do not like it

Is this supposed to be Kotlin Heroes 10 or 13

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8 months ago, hide # |
 
Vote: I like it -19 Vote: I do not like it

Футболку так и не прислали. Херня ваша платформа.

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8 months ago, hide # |
 
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A 1% chance of winning T-shirt. lessgoo

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    8 months ago, hide # ^ |
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    Last time I entered it was closer to 10%, the number of people that submitted at least one problem was about 600. I didn't enter kotlin heroes 12 though, so that might be different, but I really doubt(I entered kotlin heroes [9-11] and they all were about 10% chance to win a T-shirt)

    edit: it was 730 people for kotlin heroes 12, the first 50 doesn't participate in the chance based T-shirt, so it was 7% chance for kotlin heroes 12(and apparently I'm a liar because I seem to have submitted A) Anyways, the chances aren't low at all so I would recommend submitting at least one problem.

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      8 months ago, hide # ^ |
       
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      I participated in all from Episode 2, if I remember correctly. Bad luck I guess. :) Also, never catched top 50 either.

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        8 months ago, hide # ^ |
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        Not really, if we assume every kotlin heroes has 10% on average it would be 35% chance of not getting any.

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          8 months ago, hide # ^ |
           
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          A bit less I suppose, since that's 11 rounds from 2 to 12 and in the beginning there were only 500 valid entries. But yeah, have to wait a couple of more rounds to call myself very unlucky.

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8 months ago, hide # |
 
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hope everyone can feel delighted in this competition :))))

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8 months ago, hide # |
 
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I think it is Marvelous and Awesome! But i think it will be a bit more difficult

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8 months ago, hide # |
 
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I think it is great to put my last android development class to the test. Good luck y'all.

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8 months ago, hide # |
 
Vote: I like it +16 Vote: I do not like it

I got a T-shirt from 50 random T-shirt in Kotlin Heroes 12. Don't lose hope.

Spoiler
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8 months ago, hide # |
 
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Can anyone please explain about Kotlin Heroes round , as I am unaware about that rounds please .

Thanks

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    8 months ago, hide # ^ |
     
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    Kotlin Heroes is a special competitive programming contest organized by Codeforces in collaboration with JetBrains (the creators of Kotlin).

    The goal of the round is to encourage people to try solving problems using Kotlin instead of C++/Python/Java. The problem statements are similar in style to regular Codeforces rounds, but they are designed to help participants get comfortable with Kotlin syntax and features. You can still read the problems in English (no Kotlin knowledge required to understand them), but to submit solutions you must write them in Kotlin. Often, there are practice rounds (Warm-ups) before the main contest so you can familiarize yourself with the language.

    Fun fact: Random T-shirt giveaways are also part of these rounds, which makes them even more exciting!

    If you’d like to try it out, you can check previous rounds here: https://mirror.codeforces.com/contests/with/24

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8 months ago, hide # |
 
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Hoping to get lucky again this time :D

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8 months ago, hide # |
 
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good contest by the way

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8 months ago, hide # |
 
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Is this competition rate?

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8 months ago, hide # |
 
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Should it be better for PUPILs to register??

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8 months ago, hide # |
 
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Kotlin Heroes 11 had this in the announcement: "Using automatic translation tools (including but not limited to neural networks and AI) to convert code written in other programming languages to Kotlin goes against the spirit of the competition, so it is also strictly prohibited."

Is this still the policy/view of the organizers?

To be more specific, is IDEA's Java-to-Kotlin translation OK to use?

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    8 months ago, hide # ^ |
     
    Vote: I like it -13 Vote: I do not like it

    No it's not as per me. The main purpose of the competition is to get comfortable with Kotlin. If we code in some other languages, then it goes against the rules. Kotlin Heroes problems are made easy to solve as very less people know how to code in Kotlin. If we were allowed to do that then that would be very easy as coding those problems in Java is 10,000 times easier. Use of that will be very unfair as many people put hard work in coding in Kotlin but some other people ( who don't follow rules ) steal away their positions.

    P.S. I am not blaming anybody. Just something I felt like to share. P.S. By the way , I also don't know how to code in Kotlin and am thus not participating in the competition.

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    8 months ago, hide # ^ |
     
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    It's not OK. We've updated the announcement to include:

    The use of AI-based tools during the main contest is strictly limited.** To find out the guidelines for proper AI use, what is allowed and what is prohibited, please read the post "Rule Restricting the use of AI". Improper use of AI tools during the main contest may result in disqualification. Using automatic translation tools (including but not limited to neural networks and AI) to convert code written in other programming languages to Kotlin goes against the spirit of the competition, so it is also strictly prohibited.

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Hello everyone! I participated in the contest and achieved 26th place, solving 7 problems. Would you support me if I made a video explaining the ideas behind those 7 problems I solved and walking through my solutions, so that those who couldn’t solve them can benefit? The main goal is continuous learning. Do you support this?

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8 months ago, hide # |
 
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I am a bit stupid. Who can tell me whether it is rated?

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8 months ago, hide # |
 
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Hoping everyone participated will get a ideal result! %%%

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8 months ago, hide # |
 
Vote: I like it +16 Vote: I do not like it

How to know if you got lucky and got a t-shirt?

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