2021/day1/day1_p2.hs

   1 import Data.List
   2
   3 main :: IO ()
   4 main = do
   5     input <- readFile "input.txt"
   6     print . count . average . map read $ words input
   7
   8 average :: [Int] -> [Int]
   9 average (x:y:[]) = []
  10 average (x:y:z:xs) = x+y+z:average (y:z:xs)
  11
  12 count :: [Int] -> Int
  13 count (x:xs) = count_f x xs
  14
  15 count_f :: Int -> [Int] -> Int
  16 count_f _ [] = 0
  17 count_f nb (x:xs)
  18      | x > nb = 1 + count_f x xs
  19      | otherwise = count_f x xs
  20