Day 2: Cube Conundrum


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)
  • Code block support is not fully rolled out yet but likely will be in the middle of the event. Try to share solutions as both code blocks and using something such as https://topaz.github.io/paste/ or pastebin (code blocks to future proof it for when 0.19 comes out and since code blocks currently function in some apps and some instances as well if they are running a 0.19 beta)

FAQ


🔒This post will be unlocked when there is a decent amount of submissions on the leaderboard to avoid cheating for top spots

🔓 Edit: Post has been unlocked after 6 minutes

  • janAkali
    link
    English
    4
    edit-2
    7 months ago

    A solution in Nim language. Pretty straightforward code. Most logic is just parsing input + a bit of functional utils: allIt checks if all items in a list within limits to check if game is possible and mapIt collects red, green, blue cubes from each set of game.

    https://codeberg.org/Archargelod/aoc23-nim/src/branch/master/day_02/solution.nim

    import std/[strutils, strformat, sequtils]
    
    type AOCSolution[T] = tuple[part1: T, part2: T]
    
    type
      GameSet = object
        red, green, blue: int
      Game = object
        id: int
        sets: seq[GameSet]
    
    const MaxSet = GameSet(red: 12, green: 13, blue: 14)
    
    func parseGame(input: string): Game =
      result.id = input.split({':', ' '})[1].parseInt()
      let sets = input.split(": ")[1].split("; ").mapIt(it.split(", "))
      for gSet in sets:
        var gs = GameSet()
        for pair in gSet:
          let
            pair = pair.split()
            cCount = pair[0].parseInt
            cName = pair[1]
    
          case cName:
          of "red":
            gs.red = cCount
          of "green":
            gs.green = cCount
          of "blue":
            gs.blue = cCount
    
        result.sets.add gs
    
    func isPossible(g: Game): bool =
      g.sets.allIt(
        it.red <= MaxSet.red and
        it.green <= MaxSet.green and
        it.blue <= MaxSet.blue
      )
    
    
    func solve(lines: seq[string]): AOCSolution[int]=
      for line in lines:
        let game = line.parseGame()
    
        block p1:
          if game.isPossible():
            result.part1 += game.id
    
        block p2:
          let
            minRed = game.sets.mapIt(it.red).max()
            minGreen = game.sets.mapIt(it.green).max()
            minBlue = game.sets.mapIt(it.blue).max()
    
          result.part2 += minRed * minGreen * minBlue
    
    
    when isMainModule:
      let input = readFile("./input.txt").strip()
      let (part1, part2) = solve(input.splitLines())
    
      echo &"Part 1: The sum of valid game IDs equals {part1}."
      echo &"Part 2: The sum of the sets' powers equals {part2}."
    
      • janAkali
        link
        English
        17 months ago

        Have you joined the community?

        Yep, but it is a bit quiet in there.

        Good solution. I like your parsing with scanf. The only reason I didn’t use it myself - is that I found out about std/strscans literally yesterday.

        • cacheson
          link
          fedilink
          27 months ago

          I actually just learned about scanf while writing this. Only ended up using it in the one spot, since split worked well enough for the other bits. I really wanted to be able to use python-style unpacking, but in nim it only works for tuples. At least without writing macros, which I still haven’t been able to wrap my head around.