import Data.Bool (bool)
import Data.List (inits, intercalate, transpose)

------------------------ REP-CYCLES ----------------------

repCycles :: String -> [String]
repCycles cs =
  filter
    ((cs ==) . take n . cycle)
    ((tail . inits) $ take (quot n 2) cs)
  where
    n = length cs

--------------------------- TEST -------------------------
main :: IO ()
main =
  putStrLn $
    fTable
      "Longest cycles:\n"
      id
      ((flip bool "n/a" . last) <*> null)
      repCycles
      [ "1001110011",
        "1110111011",
        "0010010010",
        "1010101010",
        "1111111111",
        "0100101101",
        "0100100",
        "101",
        "11",
        "00",
        "1"
      ]

------------------------- GENERIC ------------------------
fTable ::
  String ->
  (a -> String) ->
  (b -> String) ->
  (a -> b) ->
  [a] ->
  String
fTable s xShow fxShow f xs =
  let rjust n c = drop . length <*> (replicate n c <>)
      w = maximum (length . xShow <$> xs)
   in unlines $
        s :
        fmap
          ( ((<>) . rjust w ' ' . xShow)
              <*> ((" -> " <>) . fxShow . f)
          )
          xs