advent05/src/advent05.hs

   1 -- import Debug.Trace
   2
   3 import Numeric
   4 import Data.List
   5
   6 main :: IO ()
   7 main =
   8   do  text <- readFile "data/advent05.txt"
   9       let passes = lines text
  10       print $ part1 passes
  11       print $ part2 passes
  12
  13 part1 = maximum . map convert
  14
  15 part2 passes = head $ expecteds \\ ns
  16   where ns = map convert passes
  17         highest = maximum ns
  18         lowest  = minimum ns
  19         expecteds = [lowest..highest]
  20
  21 directionToInt :: Char -> Int
  22 directionToInt dir = if dir `elem` "BR" then 1 else 0
  23
  24 convert :: String -> Int
  25 convert = fst . head . readInt 2 (`elem` "FBLR") directionToInt