22 lines
583 B
Haskell
22 lines
583 B
Haskell
#!/usr/bin/env stack
|
|
-- stack --resolver lts-12.5 script
|
|
|
|
module Day5A where
|
|
import Data.Bits (xor)
|
|
import Data.Char
|
|
import qualified Data.Foldable as F
|
|
|
|
invertCase :: Char -> Char
|
|
invertCase = chr . xor 0x20 . ord
|
|
|
|
calcLength :: String -> String -> Int
|
|
calcLength ys (x:y:xs)
|
|
| x == invertCase y = if null ys
|
|
then calcLength ys xs
|
|
else calcLength (tail ys) (head ys:xs)
|
|
| otherwise = calcLength (x:ys) (y:xs)
|
|
calcLength ys [x] = calcLength (x:ys) []
|
|
calcLength ys [] = length ys
|
|
|
|
main :: IO ()
|
|
main = interact $ show . calcLength "" . filter (/= '\n')
|