2023 day 12: star 1

2023/12/Main1.hs

@@ -0,0 +1,22 @@
+import Data.List.Split (splitOn)
+import Data.List (group)
+
+matchesConsecutive :: [Int] -> String -> Bool
+matchesConsecutive xs = (==) xs . map length . filter ((==) '#' . head) . group
+
+allSprings :: String -> [String]
+allSprings "" = [""]
+allSprings (x:xs) = allSprings xs >>= (\s -> map (:s) possibleChars)
+  where
+    possibleChars = if x == '?' then ['.', '#'] else [x]
+
+solve :: (String, [Int]) -> Int
+solve (springs, records) = length . filter (matchesConsecutive records) . allSprings $ springs
+
+parseLine :: String -> (String, [Int])
+parseLine l = (x, map read . splitOn "," $ y)
+  where
+    (x:y:_) = splitOn " " l
+
+main :: IO ()
+main = print . sum . map (solve . parseLine) . filter (not . null) . lines =<< readFile "data.txt"