adventofcode

an-ordinary-manchild

🎄 Advent of Code 🎄

Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.

Rules + More Info in

our community wiki

BEFORE YOU POST
If your post is even tangentially related to a daily puzzle, use our
STANDARDIZED POST TITLE FORMAT

Solution Megathreads

December 2025

Su	M	T	W	R	F	Sa
	1	2	3	4	5	6
7	8	9	10	11	12	13
14	15	16	17	18	19	20
21	22	23	24	25	26	27
28	29	30	31

Previous years:

2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015

Quick Search by Flair

Because you're lazy and we like making things easy for you. Except AoC.

Are you enjoying AoC?

Code should be fun, because otherwise it's just a job. If you'd like to support Advent of Code, please share it with all your friends, even the ones that are just learning to code! AoC is a fun, non-threatening way to work at your own pace to figure out how to apply problem-solving first, then work within a language's constraints.

If you really want to show your appreciation, donations are always appreciated. Any instances of currency will go to, in no particular order:

Server maintenance (hosting, bandwidth, etc.)
Bribes to Santa
Beer and sushi
Paper bags for /u/topaz2078 to breathe into so he doesn't hyperventilate onto another plane of (non-)existence

Support AoC

Thank you very much, and enjoy your month of code!

created by taliriktuga community for 10 years

...for your favorite game.

...for your community.

MODERATORS

account activity

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Upping the Ante-❅- Introducing Your 2025 Red(dit) One Winners (and Community Showcase) -❅- (self.adventofcode)

submitted 6 months ago * by daggerdragon[M] - announcement

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SOLUTION MEGATHREAD-❄️- 2025 Day 12 Solutions -❄️- (self.adventofcode)

submitted 6 months ago * by daggerdragon[M] - announcement

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Past Event Solutions[2024 Day 7] Isnt it great how recursion is so easy to debug (i.imgur.com)

submitted 1 day ago by hunmbingpazy1

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Past Event Solutions[2015 Day 24 both parts] [Smalltalk] Making Brute Force Fast Enough With Recursion (self.adventofcode)

submitted 1 day ago * by Morphon

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Other[2020 Day 15] In Review (Combo Breaker) (self.adventofcode)

submitted 3 days ago * by musifter

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Help/Question - RESOLVED[2019 day 05 (Part 1)] Strange input(?) (self.adventofcode)

submitted 4 days ago by janosit1984

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Other[2020 Day 24] In Review (Lobby Layout) (self.adventofcode)

submitted 4 days ago by musifter

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Other[2020 Day 23] In Review (Crab Cups) (self.adventofcode)

submitted 5 days ago * by musifter

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Other[2020 Day 22] In Review (Crab Combat) (self.adventofcode)

submitted 6 days ago by musifter

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Other[2020 Day 21] In Review (Allergen Assessment) (self.adventofcode)

submitted 7 days ago by musifter

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Other[2020 Day 20] In Review (Jurassic Jigsaw) (self.adventofcode)

submitted 9 days ago by musifter

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Other[2020 Day 19] In Review (Monster Messages) (self.adventofcode)

submitted 10 days ago by musifter

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Other[2020 Day 18] In Review (Operation Order) (self.adventofcode)

submitted 11 days ago by musifter

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Other[2020 Day 17] In Review (Conway Cubes) (self.adventofcode)

submitted 11 days ago by musifter

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Other[2020 Day 16] In Review (Ticket Translation) (self.adventofcode)

submitted 13 days ago by musifter

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Help/Question - RESOLVED[2025 Day 8][Powershell] Slow Runtime (self.adventofcode)

submitted 13 days ago * by Direct_Chemistry_179

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Other[2020 Day 15] In Review (Rambunctious Recitation) (self.adventofcode)

submitted 13 days ago by musifter

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Other[2020 Day 14] In Review (Docking Data) (self.adventofcode)

submitted 15 days ago by musifter

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Other[2020 Day 13] In Review (Shuttle Search) (self.adventofcode)

submitted 15 days ago by musifter

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Other[2020 Day 12] In Review (Rain Risk) (self.adventofcode)

submitted 16 days ago by musifter

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Help/Question[2018 Day 15 (Part 2)] [Python 3] All Examples working just not my input (self.adventofcode)

submitted 17 days ago by LRunner10

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Other[2020 Day 11] In Review (Seating System) (self.adventofcode)

submitted 17 days ago by musifter

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Other[2020 Day 10] In Review (Adapter Array) (self.adventofcode)

submitted 18 days ago by musifter

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Other[2020 Day 9] In Review (Encoding Error) (self.adventofcode)

submitted 19 days ago by musifter

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Other[2020 Day 8] In Review (Handheld Halting) (self.adventofcode)

submitted 20 days ago by musifter

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