diff options
Diffstat (limited to '19-1.hs')
| -rw-r--r-- | 19-1.hs | 24 |
1 files changed, 9 insertions, 15 deletions
@@ -1,11 +1,8 @@ import Control.Monad.ST -import Data.Foldable (foldrM) import Data.HashTable.ST.Basic as H import Data.List (nub) import Data.Maybe (mapMaybe) -import Debug.Trace - type S s = H.HashTable s String [String] -- Return Nothing if no match; unmatched remainder (can be []) if @@ -24,17 +21,14 @@ matchAny s yss xs = do in H.insert s xs r >> return r Just x -> return x -check :: S s -> [String] -> String -> ST s Bool -check s yss xs = do - zss <- nub <$> matchAny s yss xs - if [] `elem` zss - then return True - else anyM (check s yss) zss - -anyM :: Monad m => (a -> m Bool) -> [a] -> m Bool -anyM p = foldrM f False - where - f a b = (b ||) <$> p a +check :: S s -> [String] -> [String] -> ST s Bool +check s yss xss = do + zss <- nub . concat <$> mapM (matchAny s yss) xss + if null zss + then return False + else if [] `elem` zss + then return True + else check s yss zss parseTowels :: String -> [String] parseTowels = map init . words @@ -47,7 +41,7 @@ parse s = let yss = filter (not . null) . drop 2 $ lines s run :: [String] -> [String] -> ST s Int run xss yss = do ht <- H.new :: ST s (S s) - length . filter id <$> traverse (check ht yss) xss + length . filter id <$> traverse (check ht yss . pure) xss main :: IO () main = do |