-- Game.hs -- -- NOTE: This is not an example of good Haskell code. Please do not emulate. -- module Game (State, nextStates, initialState, Player (PlayerA, PlayerB), gameValue, getPlayer, simulateGame, simulateAIGame, GameValue) where import Control.Exception import Data.Maybe data Player = PlayerA | PlayerB deriving Eq data PlayerState = PlayerState Player Int [Int] data State = State PlayerState PlayerState data GameValue = BWin | Dif Int | AWin deriving (Eq, Ord) instance Show Player where show PlayerA = "A" show PlayerB = "B" instance Show PlayerState where show (PlayerState player score pits) = (show player) ++ ": " ++ (show score) ++ "; " ++ (show pits) instance Show GameValue where show BWin = "-Inf" show (Dif a) = show a show AWin = "Inf" instance Show State where show s = "| A | " ++ showpits (reverse (getPits PlayerA s)) ++ "|" ++ threechars (' ':(show (getScore PlayerB s))) ++ "|\n" ++ "|" ++ threechars (' ':((show (getScore PlayerA s)))) ++ "| " ++ showpits (getPits PlayerB s) ++ "| B |" where showpits [] = "" showpits (p:ps) = (threechars (show p)) ++ (showpits ps) threechars s@(c1:c2:c3:cs) = s threechars s = threechars (s ++ " ") otherPlayer :: Player -> Player otherPlayer PlayerA = PlayerB otherPlayer PlayerB = PlayerA initialState :: Player -> State initialState p = State (PlayerState p 0 (replicate 6 4)) (PlayerState (otherPlayer p) 0 (replicate 6 4)) getScore :: Player -> State -> Int getScore p (State (PlayerState a sa _) (PlayerState b sb _)) = if p == a then sa else sb gameValue :: State -> GameValue gameValue s = case winnerOf s of Just PlayerA -> AWin Just PlayerB -> BWin Nothing -> Dif $ (getScore PlayerA s) - (getScore PlayerB s) getPits :: Player -> State -> [Int] getPits p (State (PlayerState a _ pa) (PlayerState b _ pb)) = if p == a then pa else pb getPlayer :: State -> Player getPlayer (State (PlayerState p _ _) _) = p incStones :: PlayerState -> PlayerState incStones p = distStones [1..6] p incStonesBy :: Int -> PlayerState -> PlayerState incStonesBy n p = (iterate incStones p) !! n incScore :: Int -> PlayerState -> PlayerState incScore i (PlayerState p s ps) = (PlayerState p (s + i) ps) distStones :: [Int] -> PlayerState -> PlayerState distStones is (PlayerState p s ps) = (PlayerState p s (map (\ (i, n) -> if (elem i is) then n + 1 else n) (zip [1..6] ps))) winnerOf :: State -> Maybe Player winnerOf s@(State (PlayerState pa a _) (PlayerState pb b _)) | a >= 24 || b >= 24 = Just $ if a > b then pa else pb | otherwise = Nothing isMoveValid :: Int -> Bool isMoveValid n = elem n [1..6] isMoveLegal :: State -> Int -> Bool isMoveLegal _ n | not (isMoveValid n) = False isMoveLegal s _ | (isJust (winnerOf s)) = False isMoveLegal s n = case s of (State (PlayerState a sa pa) _) -> not $ (pa !! (n - 1)) == 0 -- Given a game state and a cup, return the next state if the player chooses -- that cup. If choosing that cup is illegal, returns Nothing. applyMove :: State -> Int -> Maybe State applyMove s n | not (isMoveLegal s n) = Nothing applyMove s n = Just (applyMove' s' p') where (s', p') = case s of (State (PlayerState a sa pa) playerother) -> ((State (PlayerState a sa (killPit pa)) playerother), pa !! (n - 1)) killPit xs = (take (n - 1) xs) ++ [0] ++ (drop n xs) -- Given a state and a number of stones from the cup, distribute them. applyMove' (State a b) p = let (rounds, extras) = divMod p 13 sinc = rounds + (if (6 - n) < extras then 1 else 0) extras' = if n == 6 then extras - 1 else if null adist then 0 else extras - (last adist) + (head adist) - 2 extras'' = if null bdist then 0 else extras' - (last bdist) + (head bdist) - 1 adist = [(n + 1)..(min 6 (extras+n))] bdist = [1..(min extras' 6)] adist' = [1..(min extras'' 6)] currP = ((incScore sinc) . (distStones adist) . (distStones adist') . (incStonesBy rounds) $ a) otherP = ((distStones bdist) . (incStonesBy rounds) $ b) in case if extras == (6 - n + 1) then (State currP otherP) else (State otherP currP) of State psa@(PlayerState pa sa [0,0,0,0,0,0]) (PlayerState pb sb cb) -> State psa (PlayerState pb (sb + (sum cb)) [0,0,0,0,0,0]) State (PlayerState pa sa ca) psb@(PlayerState pb sb [0,0,0,0,0,0]) -> State (PlayerState pa (sa + (sum ca)) [0,0,0,0,0,0]) psb s -> s -- Returns each possible move (1 to 6) and the corresponding resulting state nextMoves :: State -> [(State, Int)] nextMoves s = [(s, i) | (i, (Just s)) <- zip [1..6] (map (applyMove s) [1..6])] nextStates = (map fst) . nextMoves getMove :: State -> IO Int getMove st@(State (PlayerState p _ _) _) = do print st putStr ((show p) ++ ": ") handleJust errorCalls (\_ -> do putStrLn "Invalid move" getMove st) (do ln <- getLine evaluate (read ln) :: IO Int) simulateGame :: IO () simulateGame = simulateGame' (Just (initialState PlayerA)) where simulateGame' Nothing = return () simulateGame' jst@(Just st@(State (PlayerState p s ps) b)) = do move <- getMove st s' <- return (applyMove (State (PlayerState p s ps) b) move) case s' of Nothing -> do putStrLn $ "Invalid move " ++ (show move) simulateGame' jst (Just a) -> case winnerOf a of Just winner -> print a >> putStr ((show winner) ++ " wins!\n") Nothing -> simulateGame' s' return () maxfst (t:ts) = maxfst' t ts where maxfst' m [] = m maxfst' m (t:ts) = if (fst m) < (fst t) then maxfst' t ts else maxfst' m ts simulateAIGame :: (Ord a, Show a) => (State -> a) -> IO () simulateAIGame chooseMove = simulateGame' (Just (initialState PlayerA)) where simulateGame' Nothing = return () simulateGame' jst@(Just st@(State (PlayerState p s ps) b)) = do move <- if p == PlayerB then getMove st else do print st putStr ((show p) ++ ": ") let (states, cups) = unzip $ nextMoves st let scores = map chooseMove states let moves = zip scores cups let mv = snd $ maxfst moves putStrLn (show mv) putStrLn (show moves) return mv s' <- return (applyMove (State (PlayerState p s ps) b) move) case s' of Nothing -> if p == PlayerA then putStr "AI ERROR\n" else do putStrLn $ "Invalid move " ++ (show move) simulateGame' jst (Just a) -> case winnerOf a of Just winner -> print a >> putStr ((show winner) ++ " wins!\n") Nothing -> simulateGame' s' return ()