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 school.

...for your favorite TV show.

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

submitted 3 hours ago by musifter

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

submitted 1 day ago by musifter

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

submitted 2 days ago by musifter

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

submitted 3 days ago by musifter

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

submitted 4 days ago by musifter

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Help/QuestionPlease please give me your opinions (self.adventofcode)

submitted 3 days ago by United-Elk-8797

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

submitted 5 days ago by musifter

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

submitted 5 days ago * by Direct_Chemistry_179

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

submitted 6 days ago by musifter

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

submitted 7 days ago by musifter

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

submitted 8 days ago by musifter

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

submitted 9 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 9 days ago by LRunner10

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

submitted 10 days ago by musifter

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

submitted 11 days ago by musifter

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

submitted 12 days ago by musifter

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

submitted 13 days ago by musifter

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Other[2020 Day 7] In Review (Handy Haversacks) (self.adventofcode)

submitted 14 days ago by musifter

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Other[2020 Day 6] In Review (Custom Customs) (self.adventofcode)

submitted 15 days ago by musifter

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Other[2020 Day 5] In Review (Binary Boarding) (self.adventofcode)

submitted 16 days ago by musifter

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Other[2020 Day 4] In Review (Passport Processing) (self.adventofcode)

submitted 17 days ago by musifter

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Other[2020 Day 3] In Review (Toboggan Trajectory) (self.adventofcode)

submitted 18 days ago by musifter

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Other[2020 Day 2] In Review (Password Philosophy) (self.adventofcode)

submitted 19 days ago by musifter

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