{"id":673883,"date":"2026-01-12T20:33:14","date_gmt":"2026-01-12T19:33:14","guid":{"rendered":"https:\/\/blog.jetbrains.com\/?post_type=kotlin&#038;p=673883"},"modified":"2026-02-13T18:53:34","modified_gmt":"2026-02-13T17:53:34","slug":"advent-of-code-2025-in-kotlin","status":"publish","type":"kotlin","link":"https:\/\/blog.jetbrains.com\/ja\/kotlin\/2026\/01\/advent-of-code-2025-in-kotlin","title":{"rendered":"Advent of Code 2025 in Kotlin: Puzzles, Prizes, and Community"},"content":{"rendered":"\n<p>Thank you to everyone who participated in <a href=\"https:\/\/adventofcode.com\/2025\" target=\"_blank\" rel=\"noreferrer noopener\">Advent of Code 2025 in Kotlin<\/a>! Once again, it was a joy to see so many of you sharing solutions, cheering each other on in Slack, and keeping the holiday coding spirit alive.<\/p>\n\n\n\n<p>This year, we kicked things off with <a href=\"https:\/\/www.youtube.com\/watch?v=qJIqcGXuuQs&amp;embeds_referring_euri=https%3A%2F%2Fblog.jetbrains.com%2F\" target=\"_blank\" rel=\"noreferrer noopener\">five days of livestreams<\/a> on December 1\u20135, with Sebastian Aigner and fantastic guests solving puzzles live, discussing strategies, and showing off idiomatic Kotlin approaches.<\/p>\n\n\n\n<p>If you missed the streams or want to revisit a clever trick, you can still catch up with the recordings:<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Advent of Code 2025 in Kotlin. Day 1.\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/qJIqcGXuuQs?list=PLlFc5cFwUnmx9-VIcfxqhjHrwD3Lab4o4\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">Community<\/h1>\n\n\n\n<p>The Advent of Code puzzles remain available all year round, and so does the community energy. The <a href=\"https:\/\/slack-chats.kotlinlang.org\/c\/advent-of-code\" target=\"_blank\" rel=\"noreferrer noopener\">#advent-of-code<\/a> channel in the Kotlinlang Slack was once again full of:<\/p>\n\n\n\n<ul>\n<li>Creative Kotlin snippets<\/li>\n\n\n\n<li>Non-spoiler hints<\/li>\n\n\n\n<li>Lots of encouragement<\/li>\n<\/ul>\n\n\n\n<p>Whether you took part in discussions every day or just lurked and learned, thank you for making the channel such a friendly, collaborative space.<\/p>\n\n\n\n<p align=\"center\"><a class=\"ek-link jb-download-button\" title=\"Join the AoC channel in Slack\" href=\"https:\/\/slack-chats.kotlinlang.org\/c\/advent-of-code\" target=\"_blank\" rel=\"noopener\">Join the AoC channel in Slack<\/a><\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Winners<\/h1>\n\n\n\n<p>As in previous years, we invited you to solve Advent of Code puzzles in Kotlin, join our Kotlin leaderboards, and share your solutions on GitHub with the <code>aoc-2025-in-kotlin<\/code> topic for a chance to win special Kotlin prizes.<\/p>\n\n\n\n<p>This year, we\u2019re celebrating nine winners across three categories: Fastest to Solve, Random, and Community.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Fastest to Solve<\/h2>\n\n\n\n<p>These three contestants topped the combined Kotlin leaderboards, consistently solving the puzzles at impressive speed:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/github.com\/Kroppeb\/AdventOfCodeSolutions2\" target=\"_blank\" rel=\"noreferrer noopener\">Kroppeb<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/github.com\/AndrejStratmann\/aoc-2025-in-kotlin\" target=\"_blank\" rel=\"noreferrer noopener\">AndrejStratmann<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/github.com\/770grappenmaker\/advent-of-code\" target=\"_blank\" rel=\"noreferrer noopener\">770grappenmaker<\/a><br><\/li>\n<\/ul>\n\n\n\n<p>Congratulations on those lightning-fast stars and Kotlin-powered solutions!<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Random winners<\/h2>\n\n\n\n<p>To give everyone a chance regardless of speed, we also randomly selected three prize winners from all the participants:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/github.com\/lbcp\/AdventOfCode2025\" target=\"_blank\" rel=\"noreferrer noopener\">lbcp<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/github.com\/FelixDombek\/AdventOfCode\" target=\"_blank\" rel=\"noreferrer noopener\">FelixDombek<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/github.com\/bjdupuis\/Advent-Of-Code252\" target=\"_blank\" rel=\"noreferrer noopener\">bjdupuis<\/a><\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<p>If you see your name here, keep an eye on your inbox. We\u2019ll be in touch about your prize soon.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Community winners<\/h2>\n\n\n\n<p>Finally, Advent of Code in Kotlin wouldn\u2019t be the same without the people who answer questions, share insights and alternative solutions, help newcomers get started, and keep the #advent-of-code channel buzzing throughout December.<\/p>\n\n\n\n<p>This year, we\u2019d like to give a special shout-out to these three community stars:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/github.com\/jakubgwozdz\/advent-of-code-2025\" target=\"_blank\" data-type=\"link\" data-id=\"https:\/\/github.com\/jakubgwozdz\/advent-of-code-2025\" rel=\"noreferrer noopener\">jakubgwozdz<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/github.com\/bj0\/aoc-kotlin\" target=\"_blank\" rel=\"noreferrer noopener\">bj0<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/github.com\/ephemient\/aoc2025\" target=\"_blank\" rel=\"noreferrer noopener\">ephemient<\/a><br><\/li>\n<\/ul>\n\n\n\n<p>Thank you for your team spirit in the Kotlin community!<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Keep learning and solving<\/h1>\n\n\n\n<p>Advent of Code might be over for this year, but the puzzles and the learning opportunities remain. If you\u2019d like to keep sharpening your skills and prepare for future events, here are some resources:<\/p>\n\n\n\n<ul>\n<li><a href=\"https:\/\/www.youtube.com\/playlist?list=PLlFc5cFwUnmx9-VIcfxqhjHrwD3Lab4o4\" target=\"_blank\" rel=\"noreferrer noopener\">Advent of Code 2025 in Kotlin<\/a> YouTube playlist.<\/li>\n\n\n\n<li><a href=\"https:\/\/kotlinlang.org\/docs\/advent-of-code.html\" target=\"_blank\" rel=\"noreferrer noopener\">Solutions to Advent of Code puzzles<\/a> from previous years in idiomatic Kotlin.<\/li>\n\n\n\n<li><a href=\"https:\/\/www.youtube.com\/watch?v=nWPYGH-1hcw\" target=\"_blank\" rel=\"noreferrer noopener\">A tutorial<\/a> on how to explore and solve programming puzzles using Kotlin Notebooks.<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<p>We want to say a huge thank-you, as always, to Eric Wastl and the Advent of Code team for creating such a beloved set of puzzles year after year.<\/p>\n\n\n\n<p>Let\u2019s keep exploring Kotlin, solving algorithmic challenges, and supporting each other. We hope to see you for the next Advent of Code in Kotlin! \ud83c\udf84<\/p>\n","protected":false},"author":1212,"featured_media":673897,"comment_status":"closed","ping_status":"closed","template":"","categories":[532,89],"tags":[6828,8976,74],"cross-post-tag":[],"acf":[],"_links":{"self":[{"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/kotlin\/673883"}],"collection":[{"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/kotlin"}],"about":[{"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/types\/kotlin"}],"author":[{"embeddable":true,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/users\/1212"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/comments?post=673883"}],"version-history":[{"count":4,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/kotlin\/673883\/revisions"}],"predecessor-version":[{"id":681268,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/kotlin\/673883\/revisions\/681268"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/media\/673897"}],"wp:attachment":[{"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/media?parent=673883"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/categories?post=673883"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/tags?post=673883"},{"taxonomy":"cross-post-tag","embeddable":true,"href":"https:\/\/blog.jetbrains.com\/ja\/wp-json\/wp\/v2\/cross-post-tag?post=673883"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}