{"id":7903,"date":"2023-02-20T06:00:38","date_gmt":"2023-02-20T04:00:38","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=7903"},"modified":"2023-01-27T11:30:00","modified_gmt":"2023-01-27T09:30:00","slug":"20-feb-23","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/20-feb-23\/","title":{"rendered":"TAD de las colas: Pertenencia a una cola"},"content":{"rendered":"<p>Utilizando el <a href=\"https:\/\/bit.ly\/3QWTsRL\">tipo abstracto de datos de las colas<\/a>, definir la funci\u00f3n<\/p>\n<pre lang=\"text\">\n   perteneceCola :: Eq a => a -> Cola a -> Bool\n<\/pre>\n<p>tal que <code>perteneceCola x c<\/code> se verifica si <code>x<\/code> es un elemento de la cola <code>c<\/code>. Por ejemplo,<\/p>\n<pre lang=\"text\">\n   perteneceCola 2 (inserta 5 (inserta 2 (inserta 3 vacia))) == True\n   perteneceCola 4 (inserta 5 (inserta 2 (inserta 3 vacia))) == False\n<\/pre>\n<p><b>Soluciones<\/b><\/p>\n<p>A continuaci\u00f3n se muestran las <a href=\"#haskell\">soluciones en Haskell<\/a> y las <a href=\"#python\">soluciones en Python<\/a>.<\/p>\n<p><a name=\"haskell\"><\/a><br \/>\n<b>Soluciones en Haskell<\/b><\/p>\n<pre lang=\"haskell\">\nimport TAD.Cola (Cola, vacia, inserta, primero, resto, esVacia)\nimport Transformaciones_colas_listas colaAlista\nimport Test.QuickCheck\n\n-- 1\u00aa soluci\u00f3n\n-- ===========\n\nperteneceCola :: Eq a => a -> Cola a -> Bool\nperteneceCola x c\n  | esVacia c = False\n  | otherwise = x == primero(c) || perteneceCola x (resto c)\n\n-- 2\u00aa soluci\u00f3n\n-- ===========\n\nperteneceCola2 :: Eq a => a -> Cola a -> Bool\nperteneceCola2 x c =\n  x `elem` colaAlista c\n\n-- La funci\u00f3n colaAlista est\u00e1 definida en el ejercicio\n-- \"Transformaciones entre colas y listas\" que se encuentra en\n-- https:\/\/bit.ly\/3Xv0oIt\n\n-- Comprobaci\u00f3n de equivalencia\n-- ============================\n\n-- La propiedad es\nprop_perteneceCola :: Int -> Cola Int -> Bool\nprop_perteneceCola x p =\n  perteneceCola x p == perteneceCola2 x p\n\n-- La comprobaci\u00f3n es\n--    \u03bb> quickCheck prop_perteneceCola\n--    +++ OK, passed 100 tests.\n<\/pre>\n<p><a name=\"python\"><\/a><br \/>\n<b>Soluciones en Python<\/b><\/p>\n<pre lang=\"python\">\nfrom copy import deepcopy\nfrom typing import TypeVar\n\nfrom hypothesis import given\nfrom hypothesis import strategies as st\n\nfrom src.TAD.cola import (Cola, vacia, inserta, primero, resto, esVacia,\n                          colaAleatoria)\nfrom src.transformaciones_colas_listas import colaAlista\n\nA = TypeVar('A')\n\n# 1\u00aa soluci\u00f3n\n# ===========\n\ndef perteneceCola(x: A, c: Cola[A]) -> bool:\n    if esVacia(c):\n        return False\n    return x == primero(c) or perteneceCola(x, resto(c))\n\n# 2\u00aa soluci\u00f3n\n# ===========\n\ndef perteneceCola2(x: A, c: Cola[A]) -> bool:\n    return x in colaAlista(c)\n\n# Las funci\u00f3n colaAlista est\u00e1 definida en el ejercicio\n# \"Transformaciones entre colas y listas\" que se encuentra en\n# https:\/\/bit.ly\/3Xv0oIt\n\n# 3\u00aa soluci\u00f3n\n# ===========\n\ndef perteneceCola3Aux(x: A, c: Cola[A]) -> bool:\n    if c.esVacia():\n        return False\n    pc = c.primero()\n    c.resto()\n    return x == pc or perteneceCola3Aux(x, c)\n\ndef perteneceCola3(x: A, c: Cola[A]) -> bool:\n    c1 = deepcopy(c)\n    return perteneceCola3Aux(x, c1)\n\n# 4\u00aa soluci\u00f3n\n# ===========\n\ndef perteneceCola4Aux(x: A, c: Cola[A]) -> bool:\n    while not c.esVacia():\n        pc = c.primero()\n        c.resto()\n        if x == pc:\n            return True\n    return False\n\ndef perteneceCola4(x: A, c: Cola[A]) -> bool:\n    c1 = deepcopy(c)\n    return perteneceCola4Aux(x, c1)\n\n# Comprobaci\u00f3n de equivalencia de las definiciones\n# ================================================\n\n# La propiedad es\n@given(x=st.integers(), c=colaAleatoria())\ndef test_perteneceCola(x: int, c: Cola[int]) -> None:\n    r = perteneceCola(x, c)\n    assert perteneceCola2(x, c) == r\n    assert perteneceCola3(x, c) == r\n    assert perteneceCola4(x, c) == r\n\n# La comprobaci\u00f3n es\n#    src> poetry run pytest -q perteneceCola.py\n#    1 passed in 0.25s\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Utilizando el tipo abstracto de datos de las colas, definir la funci\u00f3n perteneceCola :: Eq a => a -> Cola a -> Bool tal que perteneceCola x c se verifica si x es un elemento de la cola c. Por ejemplo, perteneceCola 2 (inserta 5 (inserta 2 (inserta 3 vacia))) == True perteneceCola 4 (inserta&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"footnotes":"","_jetpack_memberships_contains_paid_content":false},"categories":[581],"tags":[515,585],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/7903"}],"collection":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/comments?post=7903"}],"version-history":[{"count":2,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/7903\/revisions"}],"predecessor-version":[{"id":7905,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/7903\/revisions\/7905"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=7903"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=7903"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=7903"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}