day 25

25/solution.hs

@@ -0,0 +1,45 @@
+import Data.List
+import Data.Maybe
+import qualified Data.List.Split as S
+import Debug.Trace
+
+traceOut :: Show a => a -> a
+traceOut x = (traceShow x x)
+
+addFirst :: [[a]] -> a -> [[a]]
+addFirst [] x = [[x]]
+addFirst (y:ys) x = ([x] ++ y) : ys
+
+split :: Eq a => [a] -> [a] -> [[a]]
+split _ [] = []
+split delims (x:xs)
+  | elem x delims = [[]] ++ split delims xs
+  | otherwise     = addFirst (split delims xs) x
+
+data Schematic = Key [Int] | Lock [Int] deriving (Eq, Show)
+
+splitInput :: [String] -> [Schematic]
+splitInput = map $ (\x -> case x of 
+        ((y:_):_) -> (if y == '#' then Lock else Key) $ map (length . filter (=='#')) x
+        _ -> Lock []
+    ) . transpose . split "\n"
+
+matchKeys :: Schematic -> Schematic -> Bool
+matchKeys a b = case (a, b) of
+    (Key _, Key _) -> False
+    (Lock _, Lock _) -> False
+    (Lock x, Key y) -> all (<=7) $ zipWith (+) x y
+    (Key x, Lock y) -> all (<=7) $ zipWith (+) x y
+
+solve1 :: [Schematic] -> Int
+solve1 xs = (`div` 2) $ sum $ map sum $ map (\x -> map (\y -> if matchKeys x y then 1 else 0) xs) xs
+
+main :: IO()
+main = do
+       fileinp <- readFile "input.txt"
+       let parsed = splitInput $ S.splitOn "\n\n" fileinp
+       print parsed
+       let solved1 = solve1 parsed
+--       let solved2 = solve2 parsed
+       print solved1
+--       print solved2