X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=advent15%2FMain.hs;h=40a152a188969791c03f5dbc986ccc495b8b984f;hb=e2b15781f674220586e860fb9a85b6ad0f278fad;hp=227f16018acb46da0daf10746c6e642ed180a122;hpb=513138024a69ef9f5ade5031cd945567b6510689;p=advent-of-code-21.git

diff --git a/advent15/Main.hs b/advent15/Main.hs
index 227f160..40a152a 100644
--- a/advent15/Main.hs
+++ b/advent15/Main.hs
@@ -1,12 +1,9 @@
--- Writeup at https://work.njae.me.uk/2021/12/13/advent-of-code-2021-day-13/
-
+-- Writeup at https://work.njae.me.uk/2021/12/16/advent-of-code-2021-day-15/
 
 import Debug.Trace
 
 -- import qualified Data.Text.IO as TIO
 
--- import qualified Data.Map.Strict as M
--- import Data.Map.Strict ((!))
 import qualified Data.PQueue.Prio.Min as P
 import qualified Data.Set as S
 import qualified Data.Sequence as Q
@@ -18,8 +15,6 @@ import Control.Lens hiding ((<|), (|>), (:>), (:<))
 import Data.Maybe (fromMaybe)
 import Linear (V2(..), (^+^), (^-^), (*^), (^*))
 import Data.Array.IArray
--- import Data.List
-
 
 pattern Empty   <- (Q.viewl -> Q.EmptyL)  where Empty = Q.empty
 pattern x :< xs <- (Q.viewl -> x Q.:< xs) where (:<)  = (Q.<|) 
@@ -40,7 +35,6 @@ makeLenses ''Cave
 
 type CaveContext = Reader Cave
 
-
 data Agendum s = 
     Agendum { _current :: s
             , _trail :: Q.Seq s
@@ -55,9 +49,9 @@ type ExploredStates s = S.Set s
 
 class (Eq s, Ord s, Show s) => SearchState s where
     unwrapPos :: s -> BasePosition
+    emptySearchState :: s
     successors :: s -> CaveContext (Q.Seq s)
     estimateCost :: s -> CaveContext Int
-    emptySearchState :: s
     isGoal :: s -> CaveContext Bool
     entryCost :: s -> CaveContext Int
 
@@ -69,37 +63,37 @@ instance SearchState Position where
   emptySearchState = Position (V2 0 0)
 
   -- successors :: Position -> CaveContext (Q.Seq Position)
-  successors here = 
+  successors (Position here) = 
     do grid <- asks _grid
        let neighbours = 
             filter (inRange (bounds grid))  
-              [ (unwrapPos here) ^+^ delta
+              [ here ^+^ delta
               | delta <- [V2 -1 0, V2 1 0, V2 0 -1, V2 0 1]
               ]
        let succs = Q.fromList $ map Position neighbours
        return succs
 
   -- estimateCost :: Position -> CaveContext Int
-  estimateCost here = 
+  estimateCost (Position here) = 
     do goal <- asks _goal
-       let (V2 dr dc) = (unwrapPos here) ^-^ goal
+       let (V2 dr dc) = here ^-^ goal
        return $ (abs dr) + (abs dc)
 
   -- isGoal :: here -> CaveContext Bool
-  isGoal here = 
+  isGoal (Position here) = 
     do goal <- asks _goal
-       return $ (unwrapPos here) == goal
+       return $ here == goal
 
-  entryCost here = 
+  entryCost (Position here) = 
     do grid <- asks _grid
-       return $ grid ! (unwrapPos here)
+       return $ grid ! here
 
 instance SearchState TiledPosition where
 
-  emptySearchState = TiledPosition (V2 0 0)
-
   unwrapPos (TiledPosition p) = p
 
+  emptySearchState = TiledPosition (V2 0 0)
+
   -- successors :: Position -> CaveContext (Q.Seq Position)
   successors (TiledPosition here) = 
     do grid <- asks _grid