day11

src/Days/Day08.hs

@@ -0,0 +1,54 @@
+module Days.Day08 where
+
+import AOCUtil
+import Data.Char
+import Data.List
+import GHC.Utils.Misc
+
+runA :: IO ()
+runA = interactF "data/day08.txt" (solve)
+
+runB :: IO ()
+runB = interactF "data/day08.txt" (solveB)
+
+solve :: String -> String
+solve s = show . length . filter (isVisible for) $ [(x, y) | x <- [0 .. fwidth for - 1], y <- [0 .. fheight for - 1]]
+  where
+    for = map (map readChar) . lines $ s
+
+solveB :: String -> String
+solveB s = show . maximum . map (scenicScore for) $ [(x, y) | x <- [0 .. fwidth for - 1], y <- [0 .. fheight for - 1]]
+  where
+    for = map (map readChar) . lines $ s
+
+type Forrest = [[Int]]
+
+isVisible :: Forrest -> (Int, Int) -> Bool
+isVisible f (x, y) = isLookt h left || isLookt h (tail right2) || isLookt h top || isLookt h (tail bot2)
+  where
+    row = f !! y
+    col = transpose f !! x
+    h = f !! y !! x
+    (left, right2) = splitAt x row
+    (top, bot2) = splitAt y col
+
+scenicScore :: Forrest -> (Int, Int) -> Int
+scenicScore f (x, y) = viewDist h (reverse left) * viewDist h (tail right2) * viewDist h (reverse top) * viewDist h (tail bot2)
+  where
+    row = f !! y
+    col = transpose f !! x
+    h = f !! y !! x
+    (left, right2) = splitAt x row
+    (top, bot2) = splitAt y col
+
+viewDist :: Int -> [Int] -> Int
+viewDist i ls = min (length ls) . (+ 1) . length . takeWhile (< i) $ ls
+
+isLookt :: Int -> [Int] -> Bool
+isLookt m = all (< m)
+
+fwidth :: Forrest -> Int
+fwidth = length . head
+
+fheight :: Forrest -> Int
+fheight = length