mass rename

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

day05.hs

@@ -0,0 +1,44 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ViewPatterns #-}
+
+import Data.List (foldl')
+import Data.Map (Map)
+import qualified Data.Map as M
+import Data.Text (Text)
+import qualified Data.Text as T
+import Lib (readFile')
+
+main :: IO ()
+main = do
+  input <- break (== T.empty) . T.lines <$> readFile' "day5.in"
+  let (crates, cmds) = parse input
+  putStr "Q1: "
+  print $ moveCrates T.reverse crates cmds
+  putStr "Q2: "
+  print $ moveCrates id crates cmds
+
+moveCrates :: (Text -> Text) -> [Text] -> [(Int, Int, Int)] -> Text
+moveCrates f crates' cmds = head . T.transpose . M.elems $ foldl' move crates cmds
+  where
+    crates :: Map Int Text
+    crates = M.fromList $ zip [0 ..] crates'
+    move :: Map Int Text -> (Int, Int, Int) -> Map Int Text
+    move c (n, x, y) =
+      let (h, t) = T.splitAt n $ c M.! x
+       in M.update (Just . (<>) (f h)) y $ M.insert x t c
+
+-- ugly code vs line length <= 90 🤔
+parse :: ([Text], [Text]) -> ([Text], [(Int, Int, Int)])
+parse (crates, cmds) =
+  ( [ T.filter (/= ' ') x
+      | (i, x) <- zip [0 ..] (T.transpose $ init crates),
+        i `mod` 4 == 1
+    ],
+    map
+      ( ( \["move", T.unpack -> n, "from", T.unpack -> x, "to", T.unpack -> y] ->
+            (read n, read x - 1, read y - 1)
+        )
+          . T.words
+      )
+      $ tail cmds
+  )