module Main
import Data.SortedMap

test : List Int -> IO ()
test xs = do let lst = Data.SortedMap.toList mp
             putStrLn (show lst)

--              if length lst /= n 
--                 then putStrLn $ "wrong length for " ++ show xs
--                 else do let res = map (\x => lookup x mp) xs
--                         let found = mapMaybe id res
--                         if length found /= n 
--                            then putStrLn $ "some lost in " ++ show xs ++ ": res=" ++ show res 
--                                             ++ " toList=" ++ show lst
--                            else return ()

  where  
    mp : SortedMap Int ()
    mp = foldr (\x => \m => insert x () m) empty xs
--     n : Nat
--     n = length xs

main : IO ()
main = do test [4,1,3,2]
          test [4,3,2,1]
          test [1,2,3,4]