diff --git a/haskell/Util/Poker.hs b/haskell/Util/Poker.hs new file mode 100644 index 0000000..7bd8981 --- /dev/null +++ b/haskell/Util/Poker.hs @@ -0,0 +1,106 @@ +module Util.Poker where + +import Data.Char (digitToInt) +import Data.List (sort, sortBy, group) +import Data.Ord (comparing) + +data Suit = Hearts | Diamonds | Clubs | Spades + deriving (Show, Eq, Ord) + +data Card = Card { cardValue :: Int + , cardSuit :: Suit + } + deriving (Show) + +instance Eq Card where + x == y = (cardValue x) == (cardValue y) + x /= y = (cardValue x) /= (cardValue y) + +instance Ord Card where + compare x y = compare (cardValue x) (cardValue y) + +parseCard :: String -> Card +parseCard s = parseCard' $ break (\x -> notElem x ('A':'K':'Q':'J':'T':['0'..'9'])) s + +parseCard' :: (String, String) -> Card +parseCard' (v, s) = Card v' s' + where v' = case v of + "T" -> 10 + "J" -> 11 + "Q" -> 12 + "K" -> 13 + "A" -> 14 + _ -> foldl (\x y -> x * 10 + y) 0 $ map (digitToInt) v + s' = case s of + "H" -> Hearts + "D" -> Diamonds + "C" -> Clubs + "S" -> Spades + _ -> error "Unknown card suit" + +type Hand = [Card] + +data HandRank = HighCard + | OnePair + | TwoPair + | ThreeOfAKind + | Straight + | Flush + | FullHouse + | FourOfAKind + | StraightFlush + | RoyalFlush + deriving(Show, Eq, Ord) + +type HandValue = (HandRank, [Int]) + +rankHand :: Hand -> HandValue +rankHand h + | biggestSet > 1 = rankSets grouped + | isFlush h && isStraight h = (StraightFlush, cardValues $ fixStraight h') + | isFlush h = (Flush, cardValues h') + | isStraight h = (Straight, cardValues $ fixStraight h') + | otherwise = (HighCard, cardValues h') + where h' = take 5 $ reverse $ sort h + grouped = sets $ take 5 h + biggestSet = length $ head grouped + +rankSets :: [[Card]] -> HandValue +rankSets (x:xs) = case (length x) of + 4 -> (FourOfAKind, values) + 1 -> (HighCard, cardValues $ concat (x:xs)) + _ -> case rest of + (OnePair, values') -> case l of 3 -> (FullHouse, (cardValue $ head x) : values') + 2 -> (TwoPair, (cardValue $ head x) : values') + _ -> (OnePair, values) + _ -> case l of 3 -> (ThreeOfAKind, values) + _ -> (OnePair, values) + where l = length x + rest = rankSets $ filter (\x' -> length x' <= l) xs + values = (cardValue $ head x) : (take 1 $ cardValues $ concat xs) +rankSets [] = (HighCard, []) + +cardValues :: [Card] -> [Int] +cardValues = map (cardValue) + +sets :: Hand -> [[Card]] +sets h = reverse $ sortBy (comparing (\x -> length x)) $ group $ sort h + +isFlush :: Hand -> Bool +isFlush h = suits == 5 + where groups = reverse $ sortBy (comparing (\x -> length x)) $ group $ sort $ map (cardSuit) h + suits = length $ head groups + +isStraight :: Hand -> Bool +isStraight h = isStraight' $ sort $ cardValues h + +isStraight' :: [Int] -> Bool +isStraight' [] = False +isStraight' (2:3:4:5:14:[]) = True +isStraight' xs = xs == [(head xs) .. (last xs)] + +fixStraight :: Hand -> Hand +fixStraight (x:xs) + | 2 `elem` values && 14 `elem` values = xs ++ [(Card 1 (cardSuit x))] + | otherwise = (x:xs) + where values = cardValues (x:xs) diff --git a/haskell/Util/TestPoker.hs b/haskell/Util/TestPoker.hs new file mode 100644 index 0000000..78fb411 --- /dev/null +++ b/haskell/Util/TestPoker.hs @@ -0,0 +1,21 @@ +import Test.HUnit +import Util.Poker + +testFour = [parseCard "9D", parseCard "2H", parseCard "2S", parseCard "2D", parseCard "2C"] +testThree = [parseCard "9D", parseCard "2H", parseCard "5S", parseCard "2D", parseCard "2C"] +testFull = [parseCard "9D", parseCard "2H", parseCard "9S", parseCard "2D", parseCard "2C"] +testTwo = [parseCard "9D", parseCard "2H", parseCard "9S", parseCard "2D", parseCard "5C"] +testFlush = [parseCard "9D", parseCard "2D", parseCard "KD", parseCard "JD", parseCard "5D"] +testStraight = [parseCard "9D", parseCard "TS", parseCard "JD", parseCard "QD", parseCard "KD"] +testWheel = [parseCard "2D", parseCard "3S", parseCard "4D", parseCard "5D", parseCard "AD"] + +tests = TestList [ "Rank 4 of a kind" ~: FourOfAKind ~=? (fst $ rankHand testFour) + , "Rank 3 of a kind" ~: ThreeOfAKind ~=? (fst $ rankHand testThree) + , "Rank a full house" ~: FullHouse ~=? (fst $ rankHand testFull) + , "Rank two pair" ~: TwoPair ~=? (fst $ rankHand testTwo) + , "Rank a flush" ~: Flush ~=? (fst $ rankHand testFlush) + , "Rank a straight" ~: Straight ~=? (fst $ rankHand testStraight) + , "Rank the wheel" ~: Straight ~=? (fst $ rankHand testWheel) + ] + +main = runTestTT tests