day 12

11/solution.hs

@@ -22,8 +22,8 @@ splitInput = map read . split [' '] . head . split ['\n']
 solve1 :: [Int] -> Int
 solve1 = length . foldl (.) id (take 25 $ repeat (concat . map stoneStep))
 
-solve2 :: [Int] -> Int
-solve2 xs = sum $ ((map ((memoize2 stoneCount) 75) xs) `using` parList rseq)
+solve2 :: [Int] -> Integer
+solve2 xs = sum $ map (memocount 40000) xs -- ((map ((memoize2 stoneCount) 40000) xs) `using` parList rseq)
 
 stoneStep :: Int -> [Int]
 stoneStep 0 = [1]
@@ -35,14 +35,21 @@ splitAtIndex :: Int -> [a] -> [[a]]
 splitAtIndex 0 xs = [[], xs]
 splitAtIndex a (x:xs) = addFirst (splitAtIndex (a-1) xs) x
 
-stoneCount :: Int -> Int -> Int
-stoneCount 0 = (\x -> 1)
-stoneCount n = sum . map (((memoize2 stoneCount)) (n-1)) . stoneStep
+stoneCount :: Int -> Int -> Integer
+stoneCount 0 _ = 1
+stoneCount n x 
+  | x == 0 = memocount (n-1) 1
+  | (floor $ logBase 10 $ fromIntegral x) `rem` 2 == 1 = let d = ((\x -> x `div` 2) $ (+1) $ floor $ logBase 10 $ fromIntegral x) in (memocount (n-1) (x `rem` 10^d)) + (memocount (n-1) (x `div` 10^d))
+  | otherwise = memocount (n-1) (x*2024)
+-- sum . map (((memoize2 stoneCount)) (n-1)) . stoneStep
+
+memocount = memoize2 stoneCount
 
 main :: IO()
 main = do
-       fileinp <- readFile "input.txt"
-       let parsed = splitInput fileinp
+       --fileinp <- readFile "input.txt"
+       --let parsed = splitInput fileinp
+       let parsed = [1]
        let solved1 = solve1 parsed
        let solved2 = solve2 parsed
        print solved1