Day 12: Garden Groups
Megathread guidelines
- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)
- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL
FAQ
- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268
- Where do I participate?: https://adventofcode.com/
- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465
J
Implementing flood fill or something like that would have been smart, so I didn’t do that. Instead I used a sparse-but-still-way-too-big-and-slow block matrix representation, which takes several minutes to compute the region partitions for the real problem. The rest is essentially simple, although counting edges has some picky details. The result is a lot of code though – way more than has been typical up to now.