Day 2: Cube Conundrum


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  • janAkali@lemmy.one
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    11 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@lemmy.one
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        11 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@kbin.social
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          11 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.