Part 2

Wasn’t nearly as bad as I thought

2023/day07/day07.hs

@@ -17,36 +17,40 @@ instance Ord Hand where
 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
+    [5] -> 7
+    [1, 4] -> 6 + signum j
+    [2, 3] -> 4 + 3 * signum j
+    [1, 1, 3] -> 3 + 3 * signum j
+    [1, 2, 2] -> 2 + 2 * j
+    [1, 1, 1, 2] -> 1 + 2 * signum j
+    _ -> 0 + signum j
   where
-    cList = sort $ map length $ group $ sort [x1, x2, x3, x4, x5]
+    cList = sort $ map length $ group sList
+    sList = sort [x1, x2, x3, x4, x5]
+    j = length (filter (==1) sList)
 
 main :: IO ()
 main = do
-  input <- parse <$> readFile "input"
-  print $ day07a input
+  input <- readFile "input"
+  print $ day07 (parse False input)
+  print $ day07 (parse True input)
 
 
-day07a :: [(Hand, Int)] -> Int
-day07a = sum . zipWith (*) [1..] . map snd . sort
+day07 :: [(Hand, Int)] -> Int
+day07 = sum . zipWith (*) [1..] . map snd . sort
 
-parse :: String -> [(Hand, Int)]
-parse = map (f . words) . lines
+parse :: Bool -> String -> [(Hand, Int)]
+parse p2 = map (f . words) . lines
     where f [x,y] = (parseHand x, read y)
           f x = error ("parse: Malformed input: " ++ show x)
-          parseHand = g . map digitToCard
+          parseHand = g . map (digitToCard p2)
           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
+digitToCard :: Bool -> Char -> Int
+digitToCard p2 x
   | isDigit x = digitToInt x
+  | x == 'J' && p2 = 1
   | x == 'T' = 10
   | x == 'J' = 11
   | x == 'Q' = 12