Tidying

[advent-of-code-16.git] / advent11.hs

diff --git a/advent11.hs b/advent11.hs
index 5fd4e40b784658a12580906efbbb2cb5774d336f..33bfe3c7cc2e788c03cfdc65bc46984179a0494c 100644 (file)
--- a/advent11.hs
+++ b/advent11.hs
@@ -50,6 +50,7 @@ main = do
 part1 :: IO ()
 -- part1 = print $ length $ init $ extractJust $ hillClimb [[buildingTest]] []
 part1 = print $ length $ init $ extractJust $ hillClimb [[building1]] []
+-- part1 = print $ length $ init $ extractJust $ aStar [[building1]] []
 
 part2 :: IO ()
 part2 = print $ length $ init $ extractJust $ hillClimb [[building2]] []
@@ -68,6 +69,17 @@ hillClimb (currentTrail:trails) closed =
             sortBy (\t1 t2 -> (head t1) `compare` (head t2)) $ 
             trails ++ (candidates currentTrail closed)
 
+aStar :: [[Building]] -> [Building] -> Maybe [Building]
+aStar [] _ = Nothing
+aStar (currentTrail:trails) closed = 
+    if isGoal (head currentTrail) then Just currentTrail
+    else aStar newAgenda ((head currentTrail): closed) 
+    where newAgenda = 
+            sortBy (\t1 t2 -> (trailCost t1) `compare` (trailCost t2)) $ 
+            trails ++ (candidates currentTrail closed)
+          trailCost t = estimateCost (head t) + length t - 1
+
+
 candidates :: [Building] -> [Building] -> [[Building]]
 candidates currentTrail closed = newCandidates
     where