gistfile1.hs

type Nodo = ((Int,Integer),(Int,Integer))

nivelGiros :: [(Int,Integer)] -> [(Int,Integer)]
nivelGiros xs = concatMap g xs where
    g :: (Int,Integer) -> [(Int,Integer)]
    g (n,x) = [(n,izq),(n+1,der)] where
        izq = if even x then par else rimpar
        der = if even x then rpar else impar
        par = quot x 2
        impar = quot (3*x + 1) 2
        rpar = quot (3*x + 3^(n+1) + 1) 2
        rimpar = quot (x + 3^n) 2

--

nivelArbolBilista :: [Nodo] -> [Nodo]
nivelArbolBilista xs = concatMap g xs where
    g :: Nodo -> [Nodo]
    g (a@(ni,xi),b@(nd,xd)) = [izq,der] where
        izq = ((ni,fizq b),(nd,fizq a))
        der = ((ni+1, fder b),(nd+1,fder a))
        fizq (n,x) = if even x then quot x 2 else quot (x + 3^n) 2
        fder (n,x) = if odd x
            then quot (3*x + 1) 2
            else quot (3*x + 3^(n+1) + 1) 2

{-

let z = zip (giros !! 6) (giros !! 7)
let bilista = iterate nivelArbolBilista [((2,2),(2,8))]
mapM_ print $ take 40 $ tail $ map (z !!) [0..]
mapM_ print $ take 40 $ concatMap (bilista !!) [0..]

-}


listas :: (String,String)
listas = ('0':pares,'1':impares) where
    g (_,x) = if odd x then '1' else '0'
    pares = map g p
    impares = map g i
    (p,i) = unzip $ concat $ iterate nivelArbolBilista [((2,2),(2,8))]

--

construye n = map ((\k->if k then '1' else '0').odd.snd) $
    (iterate nivelGiros [(1,2)]) !! n
pares' = construye 16
impares' = construye 17

testpares = all id $ zipWith (==) pares' (fst listas)
testimpares = all id $ zipWith (==) impares' (snd listas)