Refactor code

src/Day14.hs

@@ -0,0 +1,84 @@
+{-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
+
+module Day14
+  ( day14_1,
+    day14_2,
+  )
+where
+
+import Data.Char (isDigit)
+import Data.List (nub)
+import Data.List.Split (splitOn)
+
+type Position = (Int, Int)
+
+type Velocity = (Int, Int)
+
+type Robot = (Position, Velocity)
+
+readRobot :: String -> Robot
+readRobot s =
+  let [ps, vs] = splitOn " " s
+      [px, py] = map read . splitOn "," $ filter (\x -> isDigit x || x == ',' || x == '-') ps
+      [vx, vy] = map read . splitOn "," $ filter (\x -> isDigit x || x == ',' || x == '-') vs
+   in ((px, py), (vx, vy))
+
+moveRobot :: Int -> Robot -> Robot
+moveRobot 0 r = r
+moveRobot n r =
+  let (px, py) = fst r
+      (vx, vy) = snd r
+   in moveRobot (n - 1) (((px + vx) `mod` 101, (py + vy) `mod` 103), (vx, vy))
+
+moveRobot' :: Robot -> Robot
+moveRobot' r =
+  let (px, py) = fst r
+      (vx, vy) = snd r
+   in (((px + vx) `mod` 101, (py + vy) `mod` 103), (vx, vy))
+
+quadrant :: Robot -> Int
+quadrant r
+  | fst p `elem` [0 .. 49]
+      && snd p `elem` [0 .. 50] =
+      0
+  | fst p `elem` [51 .. 100]
+      && snd p `elem` [0 .. 50] =
+      1
+  | fst p `elem` [0 .. 49]
+      && snd p `elem` [52 .. 102] =
+      2
+  | fst p `elem` [51 .. 100]
+      && snd p `elem` [52 .. 102] =
+      3
+  | otherwise = -1
+  where
+    p = fst r
+
+findChristmasTree :: Int -> [Robot] -> Int
+findChristmasTree n rs =
+  let rs' = map moveRobot' rs
+      positions = map fst rs'
+   in if positions == nub positions
+        then n
+        else findChristmasTree (n + 1) rs'
+
+day14_1 :: IO ()
+day14_1 = do
+  contents <- lines <$> readFile "input/day14.txt"
+  let robots = map readRobot contents
+      robots' = map (moveRobot 100) robots
+      firstQ = length $ filter (\r -> quadrant r == 0) robots'
+      secondQ = length $ filter (\r -> quadrant r == 1) robots'
+      thirdQ = length $ filter (\r -> quadrant r == 2) robots'
+      fourthQ = length $ filter (\r -> quadrant r == 3) robots'
+  putStrLn $
+    "Day 14, Puzzle 1 solution: "
+      ++ show (firstQ * secondQ * thirdQ * fourthQ)
+
+day14_2 :: IO ()
+day14_2 = do
+  contents <- lines <$> readFile "input/day14.txt"
+  let robots = map readRobot contents
+  putStrLn $
+    "Day 14, Puzzle 2 solution: "
+      ++ show (findChristmasTree 1 robots)