gistfile1.hs

lcs acc (x:xs) (y:ys)
    | x == y = lcs (x:acc) xs ys
    | otherwise = (reverse acc, x:xs, y:ys)
lcs acc "" y = (reverse acc, "", y)
lcs acc x "" = (reverse acc, x, "")

s l
    | length l == 0 = (show 0)
    | otherwise = (show $ length l) ++ " " ++ l
main :: IO ()
main = do
    x <- getLine :: IO String
    y <- getLine :: IO String
    let (a, b, c) = lcs "" x y
    putStrLn $ s a
    putStrLn $ s b
    putStrLn $ s c