day2

2021/day02/day02.hs

@@ -0,0 +1,13 @@
+import Control.Arrow
+
+main :: IO ()
+main = do
+  input <- map (head . words &&& read . flip (:) [] . last) <$> lines <$> readFile "input"
+  print $ (\(x,y,z,d2) -> (x*y,x*d2)) $ day2 input (0,0,0,0)
+
+day2 :: [(String,Int)] -> (Int,Int,Int,Int) -> (Int,Int,Int,Int)
+day2 ((d,l):xs) (x,y,z,d2)
+  | d=="forward" = day2 xs (x+l,y,z,d2+l*z)
+  | d=="up" = day2 xs (x,y-l,z-l,d2)
+  | d=="down" = day2 xs (x,y+l,z+l,d2)
+day2 [] x = x