Haskell

9.hs

import Control.Monad
import Control.Applicative

replicateDo :: Int -> [b] -> [b]
replicateDo k xs = do
    x <- xs
    y <- replicate k x
    return y

desintegrateDo :: Int -> [(Int, Int)]
desintegrateDo x = do
    y <- [1..x]
    True <- return (x `mod` y == 0 && y * y <= x)
    return (y, x `div` y)

absNeighbors :: Num a => [a] -> [a]
absNeighbors xs = do
    (i, x) <- zip [1..] xs
    (j, y) <- zip [0..] xs
    True <- return (i == j)
    return $ abs (x - y)

-- Monad as Applicative
---- pure = return
---- (<*>) f x = do {f' <- f; x <- x'; return (f' x')} 

-- (>=>) f g x = join $ fmap g (f x) 
--
-- return >=> k == k
-- k >=> return == k
-- (u >=> v) >=> w == u >=> (v >=> w)