import qualified Data.Map.Strict as M
import Data.Map.Strict ((!))
-import Data.Maybe
-
data QuantifiedBag = QuantifiedBag Integer String
deriving (Show, Eq, Ord)
+qName (QuantifiedBag _ n) = n
+qCount (QuantifiedBag n _) = n
+
+type Bags = S.Set String
+type QBags = S.Set QuantifiedBag
+type BagRules = M.Map String QBags
+type InvertBags = M.Map String Bags
+
main :: IO ()
main =
do text <- TIO.readFile "data/advent07.txt"
let bags = successfulParse text
- -- print bags
- -- print $ invertBags bags
+ -- dumpBagDot bags
print $ part1 bags
print $ part2 bags
+-- dumpBagDot bags =
+-- do writeFile "a07dump.dot" "digraph {\n"
+-- mapM_ dumpABag (M.assocs bags)
+-- appendFile "a07dump.dot" "shiny_gold [fillcolor = gold1 ]\n"
+-- appendFile "a07dump.dot" "}\n"
+
+-- dumpABag (bag, contents) =
+-- mapM_ (dumpALink bag) (S.toList contents)
+
+-- dumpALink bag (QuantifiedBag n name) =
+-- do let name' = squashName name
+-- let bag' = squashName bag
+-- let txt = bag' ++ " -> " ++ name' ++ "\n"
+-- appendFile "a07dump.dot" txt
+
+-- squashName :: String -> String
+-- squashName name = [if c == ' ' then '_' else c | c <- name]
+
+
part1 bags = S.size $ S.delete "shiny gold" containers
where containers = bagsContaining (invertBags bags) (S.singleton "shiny gold") S.empty
part2 bags = (nContainedBags bags "shiny gold") - 1
+invertBags :: BagRules -> InvertBags
invertBags bags = foldr addInvert M.empty $ concatMap swapPair $ M.assocs bags
where swapPair (a, bs) = [(qName b, a) | b <- S.toList bs]
-addInvert :: (String, String) -> (M.Map String (S.Set String)) -> (M.Map String (S.Set String))
-addInvert (k, v) m =
- if k `M.member` m
- then M.insert k v' m
- else M.insert k (S.singleton v) m
- where v' = S.insert v (m!k)
+addInvert :: (String, String) -> InvertBags -> InvertBags
+addInvert (k, v) m = M.insert k v' m
+ where v' = S.insert v (M.findWithDefault S.empty k m)
-qName (QuantifiedBag _ n) = n
-qCount (QuantifiedBag n _) = n
-bagsContaining :: (M.Map String (S.Set String)) -> (S.Set String) -> (S.Set String) -> (S.Set String)
+bagsContaining :: InvertBags -> Bags -> Bags -> Bags
bagsContaining iBags agenda result
| S.null agenda = result
| otherwise = bagsContaining iBags agenda'' (S.insert thisColour result)
agenda' = S.delete thisColour agenda
agenda'' = if thisColour `S.member` result
then agenda'
- else S.union (fromMaybe S.empty (M.lookup thisColour iBags)) agenda'
+ else S.union (M.findWithDefault S.empty thisColour iBags) agenda'
-nContainedBags :: (M.Map String (S.Set QuantifiedBag)) -> String -> Integer
+nContainedBags :: BagRules -> String -> Integer
nContainedBags bags thisBag = 1 + (sum $ map subCount others)
where others = S.toList $ bags!thisBag
subCount b = (qCount b) * (nContainedBags bags (qName b))
rulesP = M.fromList <$> sepBy ruleP endOfLine
-
--- successfulParse :: Text -> [[S.Set Char]]
+successfulParse :: Text -> BagRules
successfulParse input =
case parseOnly rulesP input of
Left _err -> M.empty -- TIO.putStr $ T.pack $ parseErrorPretty err