Day 17: Clumsy Crucible

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

  • @sjmulder@lemmy.sdf.org
    link
    fedilink
    2
    edit-2
    7 months ago

    C

    Very not pretty and not efficient. Using what I think is dynamic programming - essentially I just propagate cost total through a (x, y, heading, steps in heading) state space, so every cell in that N-dimensional array holds the minimum total cost known to get to that state which is updated iteratively from the neighbours until it settles down.

    Debugging was annoying because terminals aren’t great at showing 4D grids. My mistakes were in the initial situation and missing the “4 steps to come to a stop at the end” aspect in part 2.

    https://github.com/sjmulder/aoc/blob/master/2023/c/day17.c