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
   7 main :: IO ()
   8 main =
   9   do  dataFileName <- getDataFileName
  10       numStrs <- readFile dataFileName -- "data/advent01.txt"
  11       let calories = fmap (fmap (read @Int)) $ splitWhen null $ lines numStrs
  12       print $ part1 calories
  13       print $ part2 calories
  14
  15 getDataFileName :: IO String
  16 getDataFileName =
  17   do args <- getArgs
  18      progName <- getProgName
  19      let baseDataName =  if null args
  20                          then progName
  21                          else head args
  22      let dataFileName = "data/" ++ baseDataName ++ ".txt"
  23      return dataFileName
  24
  25 part1 :: [[Int]] -> Int
  26 part1 = maximum . fmap sum
  27
  28 part2 :: [[Int]] -> Int
  29 part2 = sum . take 3 . reverse . sort . fmap sum
  30