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module Main where
import qualified Data.Map.Lazy as LMap
import Text.Parsec hiding (getInput)
import Input
type Clr = String
data Rule = Rule Clr [(Int, Clr)]
deriving (Show)
parseRule :: String -> Rule
parseRule s = case parse pRule "" s of Right r -> r ; Left e -> error (show e)
where
pRule :: Parsec String () Rule
pRule = do
clr <- pClr
symbols ["bags", "contain"]
cont <- choice [symbols ["no", "other", "bags"] >> char '.' >> return []
,pContent `sepBy1` char ',']
return (Rule clr cont)
pContent :: Parsec String () (Int, Clr)
pContent = do
n <- pNumber
clr <- pClr
choice [symbol "bag" <|> symbol "bags"]
return (n, clr)
pClr :: Parsec String () Clr
pClr = concat <$> sequence [pWord, return " ", pWord]
pNumber :: Parsec String () Int
pNumber = try (spaces >> (read <$> many1 digit)) <* notFollowedBy letter
pWord :: Parsec String () String
pWord = try $ spaces >> many1 letter
symbol :: String -> Parsec String () ()
symbol sym = try $ spaces >> string sym >> notFollowedBy letter
symbols :: [String] -> Parsec String () ()
symbols = sequence_ . map symbol
main :: IO ()
main = do
input <- map parseRule <$> getInput 7
let canContainSG =
LMap.fromList [(clr, "shiny gold" `elem` map snd cont ||
any (canContainSG LMap.!) (map snd cont))
| Rule clr cont <- input]
cumulSize =
LMap.fromList [(clr, 1 + sum (map (uncurry (*) . fmap (cumulSize LMap.!)) cont))
| Rule clr cont <- input]
:: LMap.Map Clr Int
print (sum . map fromEnum $ LMap.elems canContainSG)
print (cumulSize LMap.! "shiny gold" - 1)
|