X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=advent11%2FMain.hs;h=41b28f1f4a2ab73f1707bd8ad84dd69b6c503168;hb=47ab90651f43f37766dddc251a942142e2940653;hp=cfdbe0ea871162939205b963a3eb5f9c018ea9d2;hpb=d2427d370c43ca58800f203a6b7dcbd5a815c5a8;p=advent-of-code-23.git

diff --git a/advent11/Main.hs b/advent11/Main.hs
index cfdbe0e..41b28f1 100644
--- a/advent11/Main.hs
+++ b/advent11/Main.hs
@@ -2,8 +2,8 @@
 
 import AoC
 
-import Data.List
-import Data.Maybe
+-- import Data.List
+-- import Data.Maybe
 import Linear (V2(..), (^+^), (^-^))
 import qualified Data.Set as S
 
@@ -18,28 +18,30 @@ main =
       let galaxies = mkGalaxies text
       -- print galaxies
       -- print $ expandGalaxies galaxies 10
+
+      -- print $ allDist $ expandGalaxies 2 galaxies
+      -- print $ allDist $ expandGalaxies (10^6) galaxies
+
       print $ part1 galaxies
       print $ part2 galaxies
 
 part1, part2 :: Galaxies -> Int
-part1 galaxies = allDistances $ expandGalaxies galaxies 2
-
-part2 galaxies = allDistances $ expandGalaxies galaxies (10^6)
+part1 = allDistances . expandGalaxies 2
+part2 = allDistances . expandGalaxies 10e6
 
 allDistances :: Galaxies -> Int
-allDistances gs = case S.minView gs of
-  Nothing -> 0
-  Just (g, gs') -> (S.foldl' (
-    addDist g) 0 gs) + allDistances gs'
-  where addDist g1 acc g2 = acc + distance g1 g2
+allDistances gs = snd $ S.foldl' addGalaxy (S.empty, 0) gs
+  where addGalaxy (seen, d) new = 
+            (S.insert new seen, S.foldl' (addDist new) d seen)
+        addDist g1 d g2 = d + distance g1 g2
 
 distance :: Position -> Position -> Int
 distance g1 g2 = abs dr + abs dc
   where (V2 dr dc) = g1 ^-^ g2
 
 
-expandGalaxies :: Galaxies -> Int -> Galaxies
-expandGalaxies galaxies scale = galaxies''
+expandGalaxies :: Int -> Galaxies -> Galaxies
+expandGalaxies scale galaxies = galaxies''
   where er = emptyRows galaxies
         galaxies' = expandRows galaxies er scale
         ec = emptyCols galaxies'