Day 8: Resonant Collinearity
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
I try to use
Vecs instead ofHashSets and maps whenever the key domain is reasonably small (just the grid in this case), simply because in the end direct memory access is a lot faster than always hashing values.But looking at this case again, it is certainly a lot easier to have just
antinodes.len()at the end instead of counting all true values. This datastructure is also not really performance-critical, so aHashSetis probably the cleaner choice here.