Day 16: The Floor Will Be Lava
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
Nim
I’m caught up!
This one was pretty straighforward. Iterate through the beam path, recursively creating new beams when you hit splitters. The only gotcha is that you need a way to detect infinite loops that can be created by splitters. I opted to record energized non-special tiles as
-or|, depending on which way the beam was traveling, and then abort any path that retreads those tiles in the same way. I meant to also use+for where the beams cross, but I forgot and it turned out not to be necessary.Part 2 was pretty trivial once the code for part 1 was written.