Started on 5

aoc.cabal

@@ -62,6 +62,7 @@ executable 5
     -- other-extensions:
     build-depends:    base ^>=4.18.2.1
                     , split
+                    , containers
     hs-source-dirs:   app
     default-language: GHC2021
 executable 6

app/5.hs

@@ -2,14 +2,26 @@
 module Main where
 
 import Data.Functor
+import Data.List.Split
+import Data.Map (Map)
+import qualified Data.Map as Map
 
-parse = undefined
+parse :: String -> (Map Int [Int], [[Int]])
+parse s = let [a,b] = splitOn "\n\n" s in
+  ( foldr (\[x,y] m -> Map.insertWith (++) (read x) ([read y]) m) Map.empty . (splitOn "|" <$>) $ lines a
+  , ((read <$>) . splitOn "," <$>) $ lines b)
 
-solve1 = undefined
+fix1 :: Map Int [Int] -> [Int] -> [Int]
+fix1 _     [ ]  = [ ]
+fix1 _     [x]  = [x]
+fix1 r (x:y:es) = undefined --TODO
+
+solve1 :: Map Int [Int] -> [[Int]] -> Int
+solve1 r l = sum $ l <&> (\a -> let t = length a in a !! (t `div` 2)) . fix1 r
 
 solve2 = undefined
 
 main :: IO ()
-main = readFile "inputs/5" <&> parse >>= \i ->
-       print (solve1 i) >>
-       print (solve2 i)
+main = readFile "inputs/5.example" <&> parse >>= \i ->
+       print (uncurry solve1 i)
+       --print (solve2 i)