advent01/Main.hs

   1 -- Writeup at https://work.njae.me.uk/2022/12/01/advent-of-code-2022-day-1/
   2
   3 import System.Environment
   4 import Data.List
   5 import Data.List.Split
   6 import Data.Ord
   7
   8 main :: IO ()
   9 main =
  10   do  dataFileName <- getDataFileName
  11       numStrs <- readFile dataFileName
  12       let calories = fmap (fmap (read @Int)) $ splitWhen null $ lines numStrs
  13       print $ part1 calories
  14       print $ part2 calories
  15
  16 getDataFileName :: IO String
  17 getDataFileName =
  18   do args <- getArgs
  19      progName <- getProgName
  20      let baseDataName =  if null args
  21                          then progName
  22                          else head args
  23      let dataFileName = "data/" ++ baseDataName ++ ".txt"
  24      return dataFileName
  25
  26 part1 :: [[Int]] -> Int
  27 part1 = maximum . fmap sum
  28
  29 part2 :: [[Int]] -> Int
  30 -- part2 = sum . take 3 . reverse . sort . fmap sum
  31 part2 = sum . take 3 . sortOn Down . fmap sum
  32