aoc_kotlin VS advent-2021

[LANGUAGE: Kotlin] 757 / 504 Code

Link to solution

code

Kotlin 171/147 and a more general solution

Kotlin 1948/1806

Uses some collection helper functions and a tiny matrix math library.

Code itself is here: https://github.com/madisp/aoc_kotlin/blob/main/src/main/kotlin/day6_fast.kt

Rust https://github.com/Crazytieguy/advent-2021/blob/master/src/bin/day22/main.rs Imagining the geometry of this was very tricky for me. For a while I contemplated if calculating the intersection of each pair of cuboids would give me enough information to know how many cubes are on at the end, and finally decided that I would also have to calculate the intersections of those and so on, so I gave up. Instead I decided that my state will be a vector of cuboids that are garuanteed to be non overlapping, and on each command I would subtract the current cuboid from each of these non overlapping cuboids (leaving 1 to 6 cuboids depending on intersection), and finally either add in the current cuboid (for on command) or leave it out (for off).