advent01/Main.hs

   1 import Data.List
   2
   3 main :: IO ()
   4 main =
   5   do  numStrs <- readFile "data/advent01.txt"
   6       let nums = map (read @Int) $ lines numStrs
   7       print $ part1 nums
   8       print $ part2 nums
   9
  10 part1 :: [Int] -> Int
  11 part1 = countIncreasing
  12
  13 part2 :: [Int] -> Int
  14 part2 nums = countIncreasing $ map sum windows
  15   where windows = filter (\w -> length w == 3) $ map (take 3) $ tails nums
  16
  17 countIncreasing :: [Int] -> Int
  18 countIncreasing nums = length $ filter (> 0) $ zipWith (-) (tail nums) nums