advent11/Main.hs

   1 -- Writeup at https://work.njae.me.uk/2022/12/10/advent-of-code-2022-day-9/
   2
   3 import AoC
   4 import Data.Text (Text)
   5 import qualified Data.Text.IO as TIO
   6 import Data.Attoparsec.Text hiding (take, D)
   7 import Control.Applicative
   8 import Data.List
   9 import qualified Data.IntMap as M
  10 import Control.Lens
  11
  12 data Expression = Expression Operation Operand
  13   deriving (Show, Eq)
  14 data Operation = Plus | Times deriving (Show, Eq)
  15 data Operand = Literal Int | Old deriving (Show, Eq)
  16
  17 data MonkeyCode = MonkeyCode
  18   { _operation :: Expression
  19   , _test :: Int
  20   , _trueTarget :: Int
  21   , _falseTarget :: Int
  22   }
  23   deriving (Show, Eq)
  24 makeLenses ''MonkeyCode
  25
  26 type MoneyDescription = M.IntMap MonkeyCode
  27 type MonkeyHolds = M.IntMap [Int]
  28
  29
  30 main :: IO ()
  31 main =
  32   do  dataFileName <- getDataFileName
  33       text <- TIO.readFile dataFileName
  34       let monkeys = successfulParse text
  35       print monkeys
  36       -- let steps = expandPath path
  37       -- print $ part1 steps
  38       -- print $ part2 steps
  39
  40 -- part1, part2 :: Path -> Int
  41 -- part1 steps = S.size $ rope ^. trace
  42 --   where rope = ropeSteps (newRope 1) steps
  43
  44
  45 -- Parse the input file
  46
  47 -- pathP :: Parser [Direction]
  48 -- directionP, upP, leftP, downP, rightP :: Parser Direction
  49
  50 monkeysP = makeMonkeyMaps <$> (monkeyP `sepBy` (endOfLine <* endOfLine))
  51   where makeMonkeyMaps monkeys =
  52           ( M.fromList $ map fst monkeys
  53           , M.fromList $ map snd monkeys
  54           )
  55
  56 monkeyP = mkMonkeyPair <$> mIdP <*> startingP <*> operationP <*> testP <*> trueTargetP <*> falseTargetP
  57   where mkMonkeyPair mId holding _operation _test _trueTarget _falseTarget =
  58           ((mId, MonkeyCode{..}), (mId, holding))
  59
  60 mIdP = ("Monkey " *> decimal) <* ":" <* endOfLine
  61 startingP = ("  Starting items: " *> (decimal `sepBy` ", ")) <* endOfLine
  62 operationP = ("  Operation: new = old " *> expressionP) <* endOfLine
  63 testP = ("  Test: divisible by " *> decimal) <* endOfLine
  64 trueTargetP = ("    If true: throw to monkey " *> decimal) <* endOfLine
  65 falseTargetP = ("    If false: throw to monkey " *> decimal)
  66
  67 expressionP = Expression <$> (operatorP <* " ") <*> operandP
  68 operatorP = (Plus <$ "+") <|> (Times <$ "*")
  69 operandP = (Literal <$> decimal) <|> (Old <$ "old")
  70
  71 successfulParse :: Text -> (MoneyDescription, MonkeyHolds)
  72 successfulParse input =
  73   case parseOnly monkeysP input of
  74     Left  _err -> (M.empty, M.empty) -- TIO.putStr $ T.pack $ parseErrorPretty err
  75     Right monkeys -> monkeys