Day 2: Gift Shop
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


C
There are interesting analytical observations to be made about the problem to sidestep most of the actual iteration, but I wasn’t up to working it all out and the runtime was pretty much instant anyway.
Here’s my original solution with ints, using divions with powers of 10 to do the splitting: day02-u64.c
But I’m only doing the C implementations to prototype my assembly solutions, and dealing with 64-bit numbers, especially divisions, on x86-16 is painful, so I rewrote the solution using a fixed-length string “numbers” instead: day02.c
Still working on the assembly version
Assembly update: have part 1 working now! It’s dog slow on DOSBox, but on QEMU it’s good: day02.asm