days 20-24 (day 24 excluded for input confidentiality)

22/solution.hs

@@ -0,0 +1,74 @@
+import Data.List
+import Data.Bits
+import Data.Maybe
+import Data.Function.Memoize
+import Debug.Trace
+import Control.Parallel.Strategies
+
+traceOut :: Show a => a -> a
+traceOut x = (traceShow x x)
+
+addFirst :: [[a]] -> a -> [[a]]
+addFirst [] x = [[x]]
+addFirst (y:ys) x = ([x] ++ y) : ys
+
+split :: [Char] -> String -> [String]
+split _ [] = []
+split delims (x:xs)
+  | elem x delims = [[]] ++ split delims xs
+  | otherwise     = addFirst (split delims xs) x
+
+splitInput :: String -> [Integer]
+splitInput = map read . split "\n"
+
+evolve :: Integer -> Integer
+evolve x = c 
+    where a = ((x*64) `xor` x) `mod` 16777216 
+          b = ((a `div` 32) `xor` a) `mod` 16777216
+          c = ((b*2048) `xor` b) `mod` 16777216
+
+memoEvolve = memoize evolve
+
+firstNumbers :: Int -> Integer -> [Integer]
+firstNumbers 0 _ = []
+firstNumbers n x = x : (firstNumbers (n-1) (memoEvolve x))
+
+prices :: Integer -> [Integer]
+prices = map (`mod` 10) . firstNumbers 2000
+
+patterns :: Num a => [a] -> [(a, (a, a, a, a))]
+patterns (a:b:c:d:e:xs) = (e, (b-a, c-b, d-c, e-d)) : (patterns (b:c:d:e:xs))
+patterns _ = []
+
+sellPrice :: Eq a => (a, a, a, a) -> [(b, (a, a, a, a))] -> Maybe b
+sellPrice _ [] = Nothing
+sellPrice pattern ((a, x):xs)
+  | pattern == x = Just a
+  | otherwise    = sellPrice pattern xs
+
+solve1 :: [Integer] -> Integer
+solve1 = sum . withStrategy (parListChunk 64 rdeepseq) . map (last . firstNumbers 2000)
+
+mapPar :: NFData b => Int -> (a -> b) -> [a] -> [b]
+mapPar n f xs = (map f xs) `using` parListChunk n rdeepseq
+
+solve2 :: [Integer] -> Integer
+solve2 inits = foldl (\a b -> if a > b then a else b) 0 $ mapPar 64 (\p -> sum $ mapPar 128 (\h -> case (sellPrice p h) of
+        Nothing -> 0
+        Just x -> x
+    ) hists) ps
+    where hists = map (patterns . prices) inits
+
+test = \x -> (x <= 9) && (-9 <= x)
+
+ps = [(a, b, c, d) | a <- xs, b <- xs, c <- xs, d <- xs, test (a+b), test (b+c), test (c+d), test (a+d), test (a+b+c), test (b+c+d), test (a+b+c+d)]
+    where xs = [-9..9]
+
+main :: IO()
+main = do
+       fileinp <- readFile "input.txt"
+       let parsed = splitInput fileinp
+       let solved1 = solve1 parsed
+       let solved2 = solve2 parsed
+       print solved1
+       print solved2