import           Data.List (scanl', tails, transpose)
import           Data.Function (on)
import           Data.Bool (bool)

expandEmpty :: Int
expandEmpty = 1000000

sumDistances :: (Int, Int) -> [(Int, Int)] -> Int
sumDistances (n, d) = sum . map sumDistance
  where
    sumDistance (n', d') = n' * n * (d' - d)

genDistances :: [Int] -> [Int]
genDistances = scanl' (flip $ (+) . bool 1 expandEmpty . (== 0)) 0

solveDirection :: [String] -> Int
solveDirection = sum
  . (zipWith sumDistances <*> tail . tails)
  . (zip <*> genDistances)
  . map countHashes
  where
    countHashes = length . filter (== '#')

solveAll :: [String] -> Int
solveAll = ((+) `on` solveDirection) <*> transpose

main :: IO ()
main = print . solveAll . lines =<< readFile "data.txt"