Day 22, with stack build system

[advent-of-code-16.git] / advent18.hs

diff --git a/advent18.hs b/advent18.hs
deleted file mode 100644 (file)
index e7c304f..0000000
--- a/advent18.hs
+++ /dev/null
@@ -1,40 +0,0 @@
-import Data.List (tails)
-
--- input = "..^^."
--- input = ".^^.^.^^^^"
-input = "^.^^^.^..^....^^....^^^^.^^.^...^^.^.^^.^^.^^..^.^...^.^..^.^^.^..^.....^^^.^.^^^..^^...^^^...^...^."
-
-main :: IO ()
-main = do 
-        part1 
-        part2
-
-part1 :: IO ()
--- part1 = putStrLn $ unlines $ map (showRow) $ take 10 $ iterate nextRow $ readRow input
-part1 = print $ length $ filter (not) $ concat $ take 40 $ iterate nextRow $ readRow input
-
-part2 :: IO ()
-part2 = print $ length $ filter (not) $ concat $ take 400000 $ iterate nextRow $ readRow input
-
-readRow :: String -> [Bool]
-readRow = map (=='^')
-
-showRow :: [Bool] -> String
-showRow = map (\c -> if c then '^' else '.')
-
-extended :: [Bool] -> [Bool]
-extended row = [False] ++ row ++ [False]
-
-nextRow :: [Bool] -> [Bool]
-nextRow = map (isTrap) . segments . extended
-
-segments :: [a] -> [[a]]
-segments = filter ((==3) . length) . map (take 3) . tails
-
-isTrap :: [Bool] -> Bool
-isTrap segment
-    | segment == [True, True, False] = True
-    | segment == [False, True, True] = True
-    | segment == [True, False, False] = True
-    | segment == [False, False, True] = True
-    | otherwise = False