{"id":1213,"date":"2015-03-26T06:00:17","date_gmt":"2015-03-26T04:00:17","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=1213"},"modified":"2015-05-01T08:55:51","modified_gmt":"2015-05-01T06:55:51","slug":"pares-como-sumas-de-pares","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/pares-como-sumas-de-pares\/","title":{"rendered":"Pares como sumas de pares"},"content":{"rendered":"<p>Todo n\u00famero par se puede escribir como suma de n\u00fameros pares de varias formas. Por ejemplo,<\/p>\n<pre lang=\"text\">\n   8 = 8 \n     = 6 + 2\n     = 4 + 4\n     = 4 + 2 + 2\n     = 2 + 2 + 2 + 2\n<\/pre>\n<p>Definir la funci\u00f3n<\/p>\n<pre lang=\"text\">\n   descomposicionesDecrecientes:: Integer -> [[Integer]]\n<\/pre>\n<p>tal que (descomposicionesDecrecientes n) es la lista con las descomposiciones de n como suma de pares, en forma decreciente. Por ejemplo,<\/p>\n<pre lang=\"text\">\n   ghci> descomposicionesDecrecientes 8\n   [[8],[6,2],[4,4],[4,2,2],[2,2,2,2]]\n   ghci> descomposicionesDecrecientes 10\n   [[10],[8,2],[6,4],[6,2,2],[4,4,2],[4,2,2,2],[2,2,2,2,2]]\n   ghci> length (descomposicionesDecrecientes 100)\n   204226\n<\/pre>\n<h4>Soluciones<\/h4>\n<pre lang=\"haskell\">\ndescomposicionesDecrecientes:: Integer -> [[Integer]]\ndescomposicionesDecrecientes 0 = [[0]]\ndescomposicionesDecrecientes n = aux n [n,n-2..2]\n    where aux _ [] = []\n          aux n (x:xs) | x > n     = aux n xs\n                       | x == n    = [n] : aux n xs\n                       | otherwise = map (x:) (aux (n-x) (x:xs)) ++ aux n xs\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Todo n\u00famero par se puede escribir como suma de n\u00fameros pares de varias formas. Por ejemplo, 8 = 8 = 6 + 2 = 4 + 4 = 4 + 2 + 2 = 2 + 2 + 2 + 2 Definir la funci\u00f3n descomposicionesDecrecientes:: Integer -> [[Integer]] tal que (descomposicionesDecrecientes n) es la lista&#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":[7],"tags":[10,11,6],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/1213"}],"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=1213"}],"version-history":[{"count":4,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/1213\/revisions"}],"predecessor-version":[{"id":1283,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/1213\/revisions\/1283"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=1213"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=1213"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=1213"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}