{"id":6803,"date":"2022-03-21T06:00:41","date_gmt":"2022-03-21T04:00:41","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=6803"},"modified":"2022-03-28T07:47:05","modified_gmt":"2022-03-28T05:47:05","slug":"emparejamiento-binario","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/emparejamiento-binario\/","title":{"rendered":"Emparejamiento binario"},"content":{"rendered":"

Definir la funci\u00f3n<\/p>\n

\n   zipBinario :: [a -> b -> c] -> [a] -> [b] -> [c]\n<\/pre>\n
tal que (zipBinario fs xs ys) es la lista obtenida aplicando cada una de las operaciones binarias de fs a los correspondientes elementos de xs e ys. Por ejemplo,<\/p>\n
\n   zipBinario [(+), (*), (*)] [2,2,2] [4,4,4]    == [6,8,8]\n   zipBinario [(+)] [2,2,2] [4,4,4]              == [6]\n   zipBinario [(<), (==), (==)] \"coloca\" \"lobo\"  == [True,True,False]\n<\/pre>\n
Soluciones<\/h4>\n
\nimport Test.QuickCheck\nimport Test.QuickCheck.HigherOrder\nimport Test.Hspec\n\n-- 1\u00aa soluci\u00f3n\nzipBinario1 :: [a -> b -> c] -> [a] -> [b] -> [c]\nzipBinario1 (f:fs) (x:xs) (y:ys) = f x y : zipBinario1 fs xs ys\nzipBinario1 _ _ _                = []\n\n-- 2\u00aa soluci\u00f3n\nzipBinario2 :: [a -> b -> c] -> [a] -> [b] -> [c]\nzipBinario2 fs xs ys = [f x y | (f,(x,y)) <- zip fs (zip xs ys)]\n\n-- 3\u00aa soluci\u00f3n\nzipBinario3 :: [a -> b -> c] -> [a] -> [b] -> [c]\nzipBinario3 fs xs ys = [f x y | (f,x,y) <- zip3 fs xs ys]\n\n-- 4\u00aa soluci\u00f3n\nzipBinario4 :: [a -> b -> c] -> [a] -> [b] -> [c]\nzipBinario4 = zipWith3 id\n\n-- Verificaci\u00f3n\n-- ============\n\nespecificacion :: ([Int -> Int -> Int] -> [Int] -> [Int] -> [Int]) -> Spec\nespecificacion zipBinario = do\n  it \"e1\" $ zipBinario [(+), (*), (*)] [2,2,2] [4,4,4]    `shouldBe` [6,8,8]\n  it \"e2\" $ zipBinario [(+)] [2,2,2] [4,4,4]              `shouldBe` [6]\n\nverifica :: IO ()\nverifica = hspec $ do\n  describe \"zipBinario1\" $ especificacion zipBinario1\n  describe \"zipBinario2\" $ especificacion zipBinario2\n  describe \"zipBinario3\" $ especificacion zipBinario3\n  describe \"zipBinario4\" $ especificacion zipBinario4\n\n-- La verificaci\u00f3n es\n--    \u03bb> verifica\n--\n--    zipBinario1\n--      e1\n--      e2\n--    zipBinario2\n--      e1\n--      e2\n--    zipBinario3\n--      e1\n--      e2\n--    zipBinario4\n--      e1\n--      e2\n--\n--    Finished in 0.0016 seconds\n--    8 examples, 0 failures\n\n-- Comprobaci\u00f3n de equivalencia\n-- ============================\n\n\n-- La propiedad es\nprop_zipBinario :: [Bool -> Bool -> Bool] -> [Bool] -> [Bool] -> Bool\nprop_zipBinario fs xs ys =\n  all (== zipBinario1 fs xs ys)\n      [g fs xs ys | g <- [zipBinario2,\n                          zipBinario3,\n                          zipBinario4]]\n\n-- La comprobaci\u00f3n es\n--    \u03bb> quickCheck' prop_zipBinario\n--    +++ OK, passed 100 tests.\n\n-- Comparaci\u00f3n de eficiencia\n-- =========================\n\n-- La comparaci\u00f3n es\n--    \u03bb> maximum (zipBinario1 (cycle [(+), (*)]) [1..] [1..2*10^6])\n--    4000000000000\n--    (2.13 secs, 965,392,072 bytes)\n--    \u03bb> maximum (zipBinario2 (cycle [(+), (*)]) [1..] [1..2*10^6])\n--    4000000000000\n--    (1.86 secs, 1,109,392,176 bytes)\n--    \u03bb> maximum (zipBinario3 (cycle [(+), (*)]) [1..] [1..2*10^6])\n--    4000000000000\n--    (1.93 secs, 981,392,128 bytes)\n--    \u03bb> maximum (zipBinario4 (cycle [(+), (*)]) [1..] [1..2*10^6])\n--    4000000000000\n--    (1.07 secs, 773,392,040 bytes)\n<\/pre>\n
El c\u00f3digo se encuentra en GitHub<\/a>.<\/p>\n
La elaboraci\u00f3n de las soluciones se describe en el siguiente v\u00eddeo<\/p>\n