Day 19 - Linen Layout
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
That does mean that if two or more strings end with the same substring, you’d recalculate those substrings? Would be a faster lookup cost though, clever.
My code ran in 120ms, so its pretty damn fast as is, especially compared to the non-memoised version
edit: Tried the array of lengths method, shaved about 20ms off. Not bad, but probably not my main issue either
I hadn’t really considered that, but yes. I’m inclined to think that replacing hash table lookups with plain array indexing (which this allows) outweighs that downside but I’m not sure. Indeed 120ms is pretty damn fast!
It saved me 20ms, and given your using C, saved you dealing with uthash or similar, so probably worth it.
The hashmap is probably a more generic solution though
Certainly more generic and less prone to user error too. Indeed dealing with hash maps or any advanced data structure is a pain with C, this is where generics or templates really shine, especially if you have control over lifetime aspects as you do with C++ or Rust (e.g. moves, lvalue references, constness, etc).