Refactoring

diff --git a/advent20/Main.hs b/advent20/Main.hs
index 91f94a66cff1a5d28bdf3b5fd069424bce269b6a..48ac9e83901b16f77385b4eb65ba73fd67957ccc 100644 (file)
--- a/advent20/Main.hs
+++ b/advent20/Main.hs
@@ -1,13 +1,13 @@
--- Writeup at https://work.njae.me.uk/2024/12/16/advent-of-code-2024-day-16/
+-- Writeup at https://work.njae.me.uk/2024/12/20/advent-of-code-2024-day-20/
 
 import AoC
 
 -- import Data.Char
-import Linear (V2(..), (^+^), perp)
+import Linear (V2(..), (^+^))
 import qualified Data.Set as S
 import qualified Data.Map.Strict as M
 import Data.Maybe
-import Data.List
+-- import Data.List
 
 type Position = V2 Int -- r, c
 
@@ -38,27 +38,28 @@ main =
       -- print $ findSavings 20 track costsFromStart costsFromGoal
       print $ part1 track costsFromStart costsFromGoal
       print $ part2 track costsFromStart costsFromGoal
-      -- let allTrails = allRoutesFrom maze
-      -- -- print allTrails
-      -- print $ part1 allTrails
-      -- print $ part2 allTrails
-
--- part1, part2 :: [Agendum] -> Int
--- part1 trails = cost $ head trails
-
-findSavings cheatLen track costsFromStart costsFromGoal = fmap (\g -> (length g, head g)) $ group $ sort savings
+    
+-- findSavings cheatLen track costsFromStart costsFromGoal = fmap (\g -> (length g, head g)) $ group $ sort savings
+--   where fullCost = costsFromStart M.! track.goal
+--         cheatCosts = allCheatedCosts cheatLen track costsFromStart costsFromGoal
+--         savings = filter (> 0) $ fmap (\c -> fullCost - c) cheatCosts
+
+part1, part2 :: Track -> TrackCost -> TrackCost -> Int
+part1 = bigSavings  2 100
+part2 = bigSavings 20 100
+--   where fullCost = costsFromStart M.! track.goal
+--         cheatCosts = allCheatedCosts 2 track costsFromStart costsFromGoal
+--         savings = filter (>= 100) $ fmap (\c -> fullCost - c) cheatCosts
+-- part2 track costsFromStart costsFromGoal = length savings       
+--   where fullCost = costsFromStart M.! track.goal
+--         cheatCosts = allCheatedCosts 20 track costsFromStart costsFromGoal
+--         savings = filter (>= 100) $ fmap (\c -> fullCost - c) cheatCosts
+
+bigSavings :: Int -> Int -> Track -> TrackCost -> TrackCost -> Int
+bigSavings cheatLen savingThreshold track costsFromStart costsFromGoal = length savings
   where fullCost = costsFromStart M.! track.goal
         cheatCosts = allCheatedCosts cheatLen track costsFromStart costsFromGoal
-        savings = filter (> 0) $ fmap (\c -> fullCost - c) cheatCosts
-
-part1 track costsFromStart costsFromGoal = length savings
-  where fullCost = costsFromStart M.! track.goal
-        cheatCosts = allCheatedCosts 2 track costsFromStart costsFromGoal
-        savings = filter (>= 100) $ fmap (\c -> fullCost - c) cheatCosts
-part2 track costsFromStart costsFromGoal = length savings       
-  where fullCost = costsFromStart M.! track.goal
-        cheatCosts = allCheatedCosts 20 track costsFromStart costsFromGoal
-        savings = filter (>= 100) $ fmap (\c -> fullCost - c) cheatCosts
+        savings = filter (>= savingThreshold) $ fmap (\c -> fullCost - c) cheatCosts
 
 
 mkTrack :: String -> Track
@@ -99,7 +100,7 @@ neighbours track here =
           [ here ^+^ V2 0 1, here ^+^ V2 0 (-1), 
             here ^+^ V2 1 0, here ^+^ V2 (-1) 0 ]
 
-
+allCheatedCosts :: Int -> Track -> TrackCost -> TrackCost -> [Int]
 allCheatedCosts cheatLen track costsFromStart costsFromGoal = 
   concat [ pathCostWithCheat cheatLen track costsFromStart costsFromGoal h 
             | h <- M.keys costsFromStart