{"id":8171,"date":"2023-05-31T06:00:58","date_gmt":"2023-05-31T04:00:58","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=8171"},"modified":"2023-06-03T18:14:16","modified_gmt":"2023-06-03T16:14:16","slug":"31-may-23","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/31-may-23\/","title":{"rendered":"TAD de los grafos: Lazos de un grafo"},"content":{"rendered":"<p>Usando el <a href=\"https:\/\/bit.ly\/45cQ3Fo\">tipo abstracto de datos de los grafos<\/a>, definir las funciones,<\/p>\n<pre lang=\"text\">\n   lazos  :: (Ix v,Num p) => Grafo v p -> [(v,v)]\n   nLazos :: (Ix v,Num p) => Grafo v p -> Int\n<\/pre>\n<p>tales que<\/p>\n<ul>\n<li><code>lazos g<\/code> es el conjunto de los lazos (es decir, aristas cuyos extremos son iguales) del grafo <code>g<\/code>. Por ejemplo,<\/li>\n<\/ul>\n<pre lang=\"text\">\n     \u03bb> ej1 = creaGrafo' D (1,3) [(1,1),(2,3),(3,2),(3,3)]\n     \u03bb> ej2 = creaGrafo' ND (1,3) [(2,3),(3,1)]\n     \u03bb> lazos ej1\n     [(1,1),(3,3)]\n     \u03bb> lazos ej2\n     []\n<\/pre>\n<ul>\n<li><code>nLazos g<\/code> es el n\u00famero de lazos del grafo <code>g<\/code>. Por ejemplo,<\/li>\n<\/ul>\n<pre lang=\"text\">\n     \u03bb> nLazos ej1\n     2\n     \u03bb> nLazos ej2\n     0\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\">\nmodule Grafo_Lazos_de_un_grafo where\n\nimport TAD.Grafo (Grafo, Orientacion (D, ND), nodos, aristaEn, creaGrafo')\nimport Data.Ix (Ix)\nimport Test.Hspec (Spec, hspec, it, shouldBe)\n\nlazos :: (Ix v,Num p) => Grafo v p -> [(v,v)]\nlazos g = [(x,x) | x <- nodos g, aristaEn g (x,x)]\n\nnLazos :: (Ix v,Num p) => Grafo v p ->  Int\nnLazos = length . lazos\n\n-- Verificaci\u00f3n\n-- ============\n\nverifica :: IO ()\nverifica = hspec spec\n\nspec :: Spec\nspec = do\n  it \"e1\" $\n    lazos ej1 `shouldBe` [(1,1),(3,3)]\n  it \"e2\" $\n    lazos ej2 `shouldBe` []\n  it \"e3\" $\n    nLazos ej1 `shouldBe` 2\n  it \"e4\" $\n    nLazos ej2 `shouldBe` 0\n  where\n    ej1, ej2 :: Grafo Int Int\n    ej1 = creaGrafo' D (1,3) [(1,1),(2,3),(3,2),(3,3)]\n    ej2 = creaGrafo' ND (1,3) [(2,3),(3,1)]\n\n-- La verificaci\u00f3n es\n--      \u03bb> verifica\n--\n--      e1\n--      e2\n--      e3\n--      e4\n--\n--      Finished in 0.0005 seconds\n--      4 examples, 0 failures\n<\/pre>\n<p><a name=\"python\"><\/a><br \/>\n<b>Soluciones en Python<\/b><\/p>\n<pre lang=\"python\">\nfrom src.TAD.Grafo import (Grafo, Orientacion, Vertice, aristaEn, creaGrafo_,\n                           nodos)\n\n\ndef lazos(g: Grafo) -> list[tuple[Vertice, Vertice]]:\n    return [(x, x) for x in nodos(g) if aristaEn(g, (x, x))]\n\ndef nLazos(g: Grafo) -> int:\n    return len(lazos(g))\n\n# Verificaci\u00f3n\n# ============\n\ndef test_lazos() -> None:\n    ej1 = creaGrafo_(Orientacion.D, (1,3), [(1,1),(2,3),(3,2),(3,3)])\n    ej2 = creaGrafo_(Orientacion.ND, (1,3), [(2,3),(3,1)])\n    assert lazos(ej1) == [(1,1),(3,3)]\n    assert lazos(ej2) == []\n    assert nLazos(ej1) == 2\n    assert nLazos(ej2) == 0\n    print(\"Verificado\")\n\n# La verificaci\u00f3n es\n#    >>> test_lazos()\n#    Verificado\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Usando el tipo abstracto de datos de los grafos, definir las funciones, lazos :: (Ix v,Num p) => Grafo v p -> [(v,v)] nLazos :: (Ix v,Num p) => Grafo v p -> Int tales que lazos g es el conjunto de los lazos (es decir, aristas cuyos extremos son iguales) del grafo g. Por&#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":[453],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/8171"}],"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=8171"}],"version-history":[{"count":2,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/8171\/revisions"}],"predecessor-version":[{"id":8199,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/8171\/revisions\/8199"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=8171"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=8171"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=8171"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}