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Diffstat (limited to '2020/06-Custom_Customs/second.hs')
-rw-r--r-- | 2020/06-Custom_Customs/second.hs | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/2020/06-Custom_Customs/second.hs b/2020/06-Custom_Customs/second.hs new file mode 100644 index 0000000..10d0ff4 --- /dev/null +++ b/2020/06-Custom_Customs/second.hs @@ -0,0 +1,25 @@ +-- requires cabal install --lib split Unique +module Main (main) where + +import Control.Monad (void, when) +import Data.List (intersect, foldl') +import Data.List.Split (splitOn) +import System.Exit (die) + +exampleExpectedOutput = 6 + +parseInput :: String -> IO [String] +parseInput filename = do + input <- readFile filename + return $ map (foldl' intersect ['a'..'z'] . lines) $ splitOn "\n\n" input + +compute :: [String] -> Int +compute = sum . map length + +main :: IO () +main = do + example <- parseInput "example" + let exampleOutput = compute example + when (exampleOutput /= exampleExpectedOutput) (die $ "example failed: got " ++ show exampleOutput ++ " instead of " ++ show exampleExpectedOutput) + input <- parseInput "input" + print $ compute input |