42 lines
1.4 KiB
Haskell
42 lines
1.4 KiB
Haskell
-- requires cabal install --lib megaparsec parser-combinators heap vector
|
|
module Main (main) where
|
|
|
|
import Control.Monad (void, when)
|
|
import Data.Functor
|
|
import qualified Data.List as L
|
|
import Data.Maybe
|
|
import Data.Void (Void)
|
|
import Text.Megaparsec
|
|
import Text.Megaparsec.Char
|
|
|
|
exampleExpectedOutput = 6
|
|
|
|
type Input = ([String], [String]) -- patterns, designs
|
|
|
|
type Parser = Parsec Void String
|
|
|
|
parseInput' :: Parser Input
|
|
parseInput' = (,) <$> some (some letterChar <* optional (string ", ")) <* eol <* eol
|
|
<*> some (some letterChar <* eol) <* eof
|
|
|
|
parseInput :: String -> IO Input
|
|
parseInput filename = do
|
|
input <- readFile filename
|
|
case runParser parseInput' filename input of
|
|
Left bundle -> error $ errorBundlePretty bundle
|
|
Right input' -> return input'
|
|
|
|
compute :: Input -> Int
|
|
compute (stripes, designs) = length . filter id $ map compute' designs
|
|
where
|
|
compute' :: String -> Bool
|
|
compute' [] = True
|
|
compute' design = or $ map compute' $ catMaybes $ map (\s -> L.stripPrefix s design) stripes
|
|
|
|
main :: IO ()
|
|
main = do
|
|
example <- parseInput "example"
|
|
let exampleOutput = compute example
|
|
when (exampleOutput /= exampleExpectedOutput) (error $ "example failed: got " ++ show exampleOutput ++ " instead of " ++ show exampleExpectedOutput)
|
|
input <- parseInput "input"
|
|
print $ compute input
|