Listas duplicadas

4 Comentarios

1. Haskell

   duplica :: Eq a => [a] -> [a] duplica xs = auxD xs 0 where auxD [] _ = [] auxD [x] a | odd a = [x] | otherwise = [x,x] auxD (x:y:xs) a | x == y = x:auxD (y:xs) (a + 1) | x /= y && odd a = x:auxD (y:xs) 0 | otherwise = x:x:auxD (y:xs) 0 esDuplicada :: Eq a => [a] -> Bool esDuplicada xs = xs == duplica xs prop_duplicada :: [Int] -> Bool prop_duplicada xs = esDuplicada (duplica xs) -- λ> quickCheck prop_duplicada -- +++ OK, passed 100 tests.

   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

   duplica :: Eq a => [a] -> [a] duplica xs = auxD xs 0   where auxD [] _ = []         auxD [x] a | odd a     = [x]                    | otherwise = [x,x]         auxD (x:y:xs) a | x == y = x:auxD (y:xs) (a + 1)                         | x /= y && odd a = x:auxD (y:xs) 0                         | otherwise = x:x:auxD (y:xs) 0   esDuplicada :: Eq a => [a] -> Bool esDuplicada xs = xs == duplica xs   prop_duplicada :: [Int] -> Bool prop_duplicada xs = esDuplicada (duplica xs)   -- λ> quickCheck prop_duplicada -- +++ OK, passed 100 tests.

   Responder

2. Haskell

   import Data.List esDuplicada :: Eq a => [a] -> Bool esDuplicada xs = all even (mcdgrupos xs) where mcdgrupos xs = map (gcd 2) (longitud xs) where longitud xs = map (length) (group xs)

   1 2 3 4 5 6

   import Data.List   esDuplicada :: Eq a => [a] -> Bool esDuplicada xs = all even (mcdgrupos xs)   where mcdgrupos xs = map (gcd 2) (longitud xs)           where longitud xs = map (length) (group xs)

   Responder

3. Haskell

   import Data.List import Test.QuickCheck esDuplicada :: Eq a => [a] -> Bool esDuplicada = all (even.length) . group duplica :: Eq a => [a] -> [a] duplica xs = concatMap dupl (group xs) where dupl ys@(y:_) | (even.length) ys = ys | otherwise = y : ys prop_duplica :: Eq a => [a] -> Bool prop_duplica = esDuplicada . duplica

   1 2 3 4 5 6 7 8 9 10 11 12 13 14

   import Data.List import Test.QuickCheck   esDuplicada :: Eq a => [a] -> Bool esDuplicada = all (even.length) . group     duplica :: Eq a => [a] -> [a] duplica xs = concatMap dupl (group xs)   where dupl ys@(y:_) | (even.length) ys = ys                       | otherwise        = y : ys   prop_duplica :: Eq a => [a] -> Bool prop_duplica = esDuplicada . duplica

   Responder

4. Haskell

   import Data.List import Test.QuickCheck esDuplicada :: Eq a => [a] -> Bool esDuplicada [] = True esDuplicada xs = (even (length (head (group xs)))) && esDuplicada (concat zs) where zs = tail (group xs) duplica :: Eq a => [a] -> [a] duplica [] = [] duplica xs = concatMap doblar (group xs) doblar :: Eq a => [a] -> [a] doblar xs@(x:_) | even (length xs) = xs | otherwise = x : xs prop_duplica :: Eq a => [a] -> Bool prop_duplica xs = esDuplicada (duplica xs)

   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

   import Data.List import Test.QuickCheck   esDuplicada :: Eq a => [a] -> Bool esDuplicada [] = True esDuplicada xs =   (even (length (head (group xs)))) && esDuplicada (concat zs)   where zs = tail (group xs)   duplica :: Eq a => [a] -> [a] duplica [] = [] duplica xs = concatMap doblar (group xs)   doblar :: Eq a => [a] -> [a] doblar xs@(x:_) | even (length xs) = xs                 | otherwise        = x : xs   prop_duplica :: Eq a => [a] -> Bool prop_duplica xs = esDuplicada (duplica xs)

   Responder