import System.Random (randomRIO)

type Point = (Float, Float)

transformation1 :: Point -> Point
transformation1 (_, y) = (0, 0.16 * y)

transformation2 :: Point -> Point
transformation2 (x, y) = (0.85 * x + 0.04 * y, -0.04 * x + 0.85 * y + 1.6)

transformation3 :: Point -> Point
transformation3 (x, y) = (0.2 * x - 0.26 * y, 0.23 * x + 0.22 * y + 1.6)

transformation4 :: Point -> Point
transformation4 (x, y) = (-0.15 * x + 0.28 * y, 0.26 * x + 0.24 * y + 0.44)

applyTransformation :: Point -> Float -> Point
applyTransformation point random
  | random < 0.01 = transformation1 point
  | random < 0.86 = transformation2 point
  | random < 0.93 = transformation3 point
  | otherwise = transformation4 point

genNextPoint :: Point -> IO Point
genNextPoint point = do
  random <- randomRIO (0.0, 1.0 :: Float)
  return $ applyTransformation point random

barnsleyFern :: Point -> Int -> IO [Point]
barnsleyFern _ 0 = return []
barnsleyFern startPoint n = do
  x' <- genNextPoint startPoint
  xs <- barnsleyFern x' (n - 1)
  return (startPoint : xs)

main :: IO ()
main = do
  putStrLn "Укажите количество шагов рекурсии:"
  input <- getLine
  let n = read input :: Int
  fractal <- barnsleyFern (0, 0) n
  print fractal