{-# LANGUAGE ScopedTypeVariables, LambdaCase, ViewPatterns, TupleSections #-} {-# LANGUAGE BangPatterns #-} import Control.Applicative import Control.Arrow import Control.Monad import Data.Array.Unboxed import Data.Function import Data.List import Data.Maybe import Data.Monoid import Data.IORef import Data.STRef import Debug.Trace import System.CPUTime import System.IO import System.IO.Unsafe import System.Random import System.Timeout import qualified Data.Array.ST as STA import qualified Data.Foldable as F import qualified Data.Traversable as T main :: IO () main = do hSetBuffering stdout NoBuffering -- DO NOT REMOVE opponentCount <- readLn forever $ do (gameRound :: Int) <- readLn [read -> (myX :: Int), read -> (myY :: Int), (/= 0) . read -> myBackInTimeLeft] <- words <$> getLine opponents <- replicateM opponentCount $ do [read -> (x :: Int), read -> (y :: Int), (/= 0) . read -> backInTimeLeft] <- words <$> getLine return ((x, y), backInTimeLeft) -- '.' for empty, '0' for me, otherwise ID of opponent grid <- fmap (array ((0,0),(34,19)) . concat) $ forM [0..19] $ \y -> zipWith (\x c -> ((x,y),c)) [0..] <$> getLine let claim c pt grid = if grid!pt == '.' then grid // [(pt,c)] else grid startTime <- getCPUTime gen <- newStdGen let (action, nPts) = findTarget (myX, myY) (claim 'X' (myX,myY) grid) opponents myBackInTimeLeft gen -- action: "x y" to move or "BACK rounds" to go back in time case action of Left n -> putStrLn $ "BACK " ++ show n Right (tx, ty) -> putStrLn $ unwords $ map show [tx, ty] stopTime <- getCPUTime let diff = stopTime - startTime hPutStrLn stderr $ show (diff `div` 1000000000) ++ " " ++ show nPts findTarget :: RandomGen g => (Int, Int) -> UArray (Int, Int) Char -> [((Int, Int), Bool)] -> Bool -> g -> (Either Int (Int, Int), Int) findTarget myPt@(myX,myY) grid opponents myBackInTimeLeft gen = (Right $ fromMaybe myPt $ fmap fst $ safeMaximumBy (compare `on` snd) scoredPts, length scoredPts) where scoredPts = unsafeTimeoutList 90000 . map (\pt -> let rt = bestRoute grid myPt pt in (head rt,) $! score rt) . map fst . sortBy (compare `on` snd) . map (\(r, (x,y)) -> ((x,y), r + dist myPt (x,y))) . zip (randomRs (0, 2.0::Double) gen) . filter (\p -> inRange (bounds grid) p && grid!p == '.') $ indices grid baseScore = scoreGrid' myPt grid score rt = (scoreGrid' (last rt) (updateGrid grid rt) - baseScore) / (fromIntegral (length rt) ** 2) scoreGrid' pt grid = scoreGrid grid + 3 * sum (map (sqrt . dist pt . fst) opponents) dist (x0,y0) (x1,y1) = fromIntegral (abs (x1-x0) + abs (y1-y0)) neighbours :: (Int,Int) -> Int -> [(Int,Int)] neighbours (x0,y0) n = [0..2*n-1] >>= \i -> [ (x0-n+i,y0-n) , (x0+n,y0-n+i) , (x0+n-i,y0+n) , (x0-n,y0+n-i) ] bestRoute :: UArray (Int,Int) Char -> (Int,Int) -> (Int,Int) -> [(Int,Int)] bestRoute grid from@(x0,y0) to@(x1,y1) = if freeCells rt1 < freeCells rt2 then rt2 else rt1 where freeCells = count (\p -> grid!p == '.') rt1 = map (,y0) (x0 `to` x1) ++ map (x1,) (y0 `to` y1) rt2 = map (x0,) (y0 `to` y1) ++ map (,y1) (x0 `to` x1) x `to` y | y >= x = [x+1..y] | otherwise = [x-1,x-2..y] updateGrid :: UArray (Int,Int) Char -> [(Int, Int)] -> UArray (Int,Int) Char updateGrid grid route = STA.runSTUArray $ do let valid = inRange (bounds grid) grid' <- STA.thaw grid forM_ route $ \p -> when (grid!p == '.') $ STA.writeArray grid' p '0' doWhileM_ . fmap getAny . flip foldMapA (indices grid) $ \p -> do g <- STA.readArray grid' p if g /= '.' then pure (Any False) else do gs <- mapM (\p' -> if valid p' then STA.readArray grid' p' else pure 'X') (neighbours p 1) if any (not . (`elem` ['.','0'])) gs then Any True <$ STA.writeArray grid' p 'M' else pure (Any False) forM_ (indices grid) $ \p -> do g <- STA.readArray grid' p if g == '.' then STA.writeArray grid' p '0' else when (g == 'M') $ STA.writeArray grid' p '.' return grid' filterA :: Applicative f => (a -> f Bool) -> [a] -> f [a] filterA f [] = pure [] filterA f (x:xs) = (\c xs' -> if c then x:xs' else xs') <$> f x <*> filterA f xs safeMaximumBy :: (a -> a -> Ordering) -> [a] -> Maybe a safeMaximumBy _ [] = Nothing safeMaximumBy f xs = Just $ maximumBy f xs safeMinimumBy :: (a -> a -> Ordering) -> [a] -> Maybe a safeMinimumBy _ [] = Nothing safeMinimumBy f xs = Just $ minimumBy f xs whileM_ :: Monad m => m Bool -> m a -> m () whileM_ mc m = mc >>= \c -> when c (m >> whileM_ mc m) doWhileM_ :: Monad m => m Bool -> m () doWhileM_ mc = mc >>= \c -> when c (doWhileM_ mc) count :: (a -> Bool) -> [a] -> Int count f xs = go xs 0 where go [] !n = n go (x:xs) !n = go xs $ if f x then n+1 else n -- Compute elements of the list to WHNF for `t` microseconds. -- After `t` microseconds, abandon the calculation and terminate -- the list. Note that this causes the length of the result to depend -- on timing and system load. Marked "unsafe" for a reason! unsafeTimeoutList :: Integer -> [a] -> [a] unsafeTimeoutList t xs = unsafePerformIO $ do start <- getCPUTime return $ evalUntil (start + (1000000 * t)) xs where evalUntil end xs = unsafePerformIO $ do now <- getCPUTime r <- timeout (fromIntegral $ max 0 (end - now) `div` 1000000) $ return $! case xs of [] -> [] (a:as) -> a `seq` (a:as) return $ case r of Nothing -> [] Just [] -> [] Just (a:as) -> (a : evalUntil end as) foldMapA :: (Applicative f, F.Foldable t, Monoid v) => (a -> f v) -> t a -> f v foldMapA f t = F.foldr (\x v -> mappend <$> v <*> f x) (pure mempty) t scoreGrid :: UArray (Int, Int) Char -> Double scoreGrid grid = sum $ map (sqrt . fromIntegral) $ elems $ scoreCells grid scoreCells :: UArray (Int, Int) Char -> UArray (Int, Int) Int scoreCells grid = STA.runSTUArray $ do scores <- STA.newArray (bounds grid) 80 doWhileM_ $ do fmap getAny $ flip foldMapA (assocs grid) $ \(p,g) -> do v <- STA.readArray scores p nv <- mapM (STA.readArray scores) (neighbours p) let outside = 8 - length (neighbours p) let free = count ((=='.') . (grid!)) $ neighbours p let mine = count ((=='0') . (grid!)) $ neighbours p let other = 8 - (outside + mine + free) let v' | g == '0' = 100 + 10*mine + 35*(min 1 $ outside + other) + 10*free | g /= '.' = 0 | isBorder p = 0 | otherwise = min v $ minimum nv + (max 0 $ 2*mine - other) + 1 when (v' /= v) $ STA.writeArray scores p v' return $ Any (v' /= v) return scores where isBorder (x,y) = x == xMin || x == xMax || y == yMin || y == yMax where ((xMin,yMin),(xMax,yMax)) = bounds grid neighbours (x,y) = filter (inRange $ bounds grid) $ diagonals (x,y) 1