day 15: extra naive solution

too slow ┐(￣ー￣)┌

2022/day15/day15.hs

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+import Data.List.Split
+import qualified Data.Map as M
+import Control.Lens
+import Data.List
+import Linear.V2
+
+type Sensor = (V2 Int, V2 Int)
+type Cave = M.Map (V2 Int) Char
+
+main :: IO ()
+main = do
+  input <- map (splitOneOf "=,:") . lines <$> readFile "input"
+  let p = map parse input
+  let c = M.fromList $ fillCave p
+  putStrLn $ intercalate "\n" $ print2D 50 $ map fst $ M.toList c
+  let f = fillCave2 p
+  print $ M.filterWithKey (\(V2 _ a) b -> a == 10) f
+  print $ length $ M.filterWithKey (\(V2 _ a) b -> a == 10 && b == '#') $ M.union f c
+
+parse :: [String] -> Sensor
+parse [_, a, _, b, _, c, _, d] = (V2 (read a) (read b), V2 (read c) (read d))
+
+dist :: Sensor -> Int
+dist (a, b) = sum $ abs $ a - b
+
+fillCave :: [Sensor] -> [(V2 Int, Char)]
+fillCave (x:xs) = sensor ++ fillCave xs
+    where d = dist x
+          pRel = [V2 x y | x<-[(-d)..(d)],y<-[(-d)..(d)], abs x + abs y <= d]
+          sensor = zip (map (+fst x) pRel) (repeat '#')
+fillCave [] = []
+
+fillCave2 :: [Sensor] -> Cave
+fillCave2 (x:xs) = newC `M.union` fillCave2 xs
+    where newC = M.insert (snd x) 'B' $ M.insert (fst x) 'S' (M.empty)
+fillCave2 [] = M.empty
+
+
+
+
+
+
+
+
+
+
+
+p :: Int -> [Int] -> String
+p n (x:xs) =
+  if n == x
+    then '#' : p (n + 1) xs
+    else '.' : p (n + 1) (x : xs)
+p _ [] = []
+
+print2D :: Int -> [V2 Int] -> [String]
+print2D n coords
+  | n == pred minY = []
+  | otherwise = p minX line : print2D (n - 1) coords
+  where
+    line = nub $ sort $ map (^. _x) (filter (\(V2 _ a) -> a == n) coords)
+    minY = minimum $ map (^. _y) coords
+    minX = minimum $ map (^. _x) coords

2022/day15/testinput

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+Sensor at x=2, y=18: closest beacon is at x=-2, y=15
+Sensor at x=9, y=16: closest beacon is at x=10, y=16
+Sensor at x=13, y=2: closest beacon is at x=15, y=3
+Sensor at x=12, y=14: closest beacon is at x=10, y=16
+Sensor at x=10, y=20: closest beacon is at x=10, y=16
+Sensor at x=14, y=17: closest beacon is at x=10, y=16
+Sensor at x=8, y=7: closest beacon is at x=2, y=10
+Sensor at x=2, y=0: closest beacon is at x=2, y=10
+Sensor at x=0, y=11: closest beacon is at x=2, y=10
+Sensor at x=20, y=14: closest beacon is at x=25, y=17
+Sensor at x=17, y=20: closest beacon is at x=21, y=22
+Sensor at x=16, y=7: closest beacon is at x=15, y=3
+Sensor at x=14, y=3: closest beacon is at x=15, y=3
+Sensor at x=20, y=1: closest beacon is at x=15, y=3