day07 part 1

part 2 might mess things up a little

2023/day07/day07.hs

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+import Data.Function (on)
+import Data.List
+import Data.Char
+
+data Hand =
+  C Int Int Int Int Int
+  deriving (Eq, Show)
+
+instance Ord Hand where
+  compare x y =
+    let r = (compare `on` handType) x y
+        f (C x1 x2 x3 x4 x5) = (x1, x2, x3, x4, x5)
+     in case r of
+          EQ -> (compare `on` f) x y
+          _ -> r
+
+handType :: Hand -> Int
+handType (C x1 x2 x3 x4 x5) =
+  case cList of
+    [5] -> 6
+    [1, 4] -> 5
+    [2, 3] -> 4
+    [1, 1, 3] -> 3
+    [1, 2, 2] -> 2
+    [1, 1, 1, 2] -> 1
+    _ -> 0
+  where
+    cList = sort $ map length $ group $ sort [x1, x2, x3, x4, x5]
+
+main :: IO ()
+main = do
+  input <- parse <$> readFile "input"
+  print $ day07a input
+
+
+day07a :: [(Hand, Int)] -> Int
+day07a = sum . zipWith (*) [1..] . map snd . sort
+
+parse :: String -> [(Hand, Int)]
+parse = map (f . words) . lines
+    where f [x,y] = (parseHand x, read y)
+          f x = error ("parse: Malformed input: " ++ show x)
+          parseHand = g . map digitToCard
+          g [x1, x2, x3, x4, x5] = C x1 x2 x3 x4 x5
+          g x = error ("parseHand: Malformed input: " ++ show x)
+
+digitToCard :: Char -> Int
+digitToCard x
+  | isDigit x = digitToInt x
+  | x == 'T' = 10
+  | x == 'J' = 11
+  | x == 'Q' = 12
+  | x == 'K' = 13
+  | x == 'A' = 14
+  | otherwise = error ("digitToCard: Malformed input: " ++ show x)

2023/day07/testinput

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+32T3K 765
+T55J5 684
+KK677 28
+KTJJT 220
+QQQJA 483