Tidying

diff --git a/advent17.hs b/advent17.hs
index d255a09bf594b6c8d8dca64daa2f103778dd6ec5..c99b8da2aabdac93d5b5344110d0a3209510fece 100644 (file)
--- a/advent17.hs
+++ b/advent17.hs
@@ -1,11 +1,8 @@
-import Data.List (subsequences, (\\), sort, sortBy)
-import Data.Ord (comparing)
 import Data.ByteString.Char8 (pack)
-import Crypto.Hash (hash, Digest, MD5)
-
+import qualified Crypto.Hash as C
 
 type Position = (Int, Int)
-data Agendum = Agendum {position :: Position, path :: String, hsh :: String} deriving (Show, Eq)
+data Agendum = Agendum {position :: Position, path :: String, hash :: String} deriving (Show, Eq)
 type Agenda = [Agendum]
 
 -- input = "hijkl"
@@ -13,46 +10,39 @@ type Agenda = [Agendum]
 
 input = "qljzarfv" -- my input
 
-
-
 main :: IO ()
 main = do 
     part1 
     part2 
 
-initialAgenda = [Agendum {position=(1, 1), path="", hsh=(getHash "")}]
-
-
 part1 :: IO ()
 part1 = print $ path $ extractJust $ bfs initialAgenda
 
 part2 :: IO ()
 part2 = print $ bfs2 initialAgenda 0
 
+initialAgenda :: Agenda
+initialAgenda = [Agendum {position=(1, 1), path="", hash=(getHash "")}]
 
 getHash :: String -> String
-getHash path = show (hash $ pack (input ++ path) :: Digest MD5)
-
+getHash path = show (C.hash $ pack (input ++ path) :: C.Digest C.MD5)
 
 extractJust :: Maybe Agendum -> Agendum
 extractJust Nothing = head initialAgenda
 extractJust (Just x) = x
 
-
 bfs :: Agenda -> Maybe Agendum
 bfs [] = Nothing
 bfs (current:agenda) = 
     if isGoal current then Just current
     else bfs (agenda ++ (successors current))
 
-
 bfs2 :: Agenda -> Int -> Int
 bfs2 [] l = l
 bfs2 (current:agenda) l = 
     if isGoal current then bfs2 agenda (length $ path $ current)
     else bfs2 (agenda ++ (successors current)) l
 
-
 isGoal :: Agendum -> Bool
 isGoal agendum = (position agendum) == (4, 4)
 
@@ -62,25 +52,23 @@ isLegalPos p = fst p >= 1 && fst p <= 4 && snd p >= 1 && snd p <= 4
 successors :: Agendum -> Agenda
 successors state = [Agendum {position = step p0 ld, 
                              path = path0 ++ [ld],
-                             hsh = getHash (path0 ++ [ld])} | ld <- legalDoors ]
+                             hash = getHash (path0 ++ [ld])} | ld <- legalDoors ]
     where 
         p0 = position state
         path0 = path state
-        h0 = hsh state
+        h0 = hash state
         doors = openDoors h0
         legalDoors = filter (isLegalPos . (step p0)) doors
 
-openDoors hash = (u hash) ++ (d hash) ++ (l hash) ++ (r hash)
+openDoors :: String -> String
+openDoors h = (u h) ++ (d h) ++ (l h) ++ (r h)
 
-u hash = if hash!!0 `elem` "bcdef" then "U" else ""
-d hash = if hash!!1 `elem` "bcdef" then "D" else ""
-l hash = if hash!!2 `elem` "bcdef" then "L" else ""
-r hash = if hash!!3 `elem` "bcdef" then "R" else ""
+u h = if h!!0 `elem` "bcdef" then "U" else ""
+d h = if h!!1 `elem` "bcdef" then "D" else ""
+l h = if h!!2 `elem` "bcdef" then "L" else ""
+r h = if h!!3 `elem` "bcdef" then "R" else ""
 
 step (r, c) 'U' = (r-1, c)
 step (r, c) 'D' = (r+1, c)
 step (r, c) 'L' = (r, c-1)
 step (r, c) 'R' = (r, c+1)
-
-
-