{"id":3405,"date":"2017-11-13T06:00:20","date_gmt":"2017-11-13T04:00:20","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=3405"},"modified":"2022-03-25T20:09:50","modified_gmt":"2022-03-25T18:09:50","slug":"numeros-oblongos","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/numeros-oblongos\/","title":{"rendered":"N\u00fameros oblongos"},"content":{"rendered":"<p>Un <a href=\"http:\/\/bit.ly\/2hnhMw6\">n\u00famero oblongo<\/a> es un n\u00famero que es el producto de dos n\u00fameros naturales consecutivos; es decir, n es un n\u00famero oblongo si existe un n\u00famero natural x tal que n = x(x+1). Por ejemplo, 42 es un n\u00famero oblongo porque 42 = 6 x 7.<\/p>\n<p>Definir las funciones<\/p>\n<pre lang=\"text\">\n   esOblongo :: Integer -> Bool\n   oblongos  :: [Integer]\n<\/pre>\n<p>tales que<\/p>\n<ul>\n<li>(esOblongo n) se verifica si n es oblongo. Por ejemplo,<\/li>\n<\/ul>\n<pre lang=\"text\">\n     esOblongo 42               ==  True\n     esOblongo 40               ==  False\n     esOblongo 100000010000000  ==  True\n<\/pre>\n<ul>\n<li>oblongos es la suceci\u00f3n de los n\u00fameros oblongos. Por ejemplo, <\/li>\n<\/ul>\n<pre lang=\"text\">\n     take 15 oblongos   == [0,2,6,12,20,30,42,56,72,90,110,132,156,182,210]\n     oblongos !! 50     == 2550\n     oblongos !! (10^7) == 100000010000000\n<\/pre>\n<h4>Soluciones<\/h4>\n<pre lang=\"haskell\">\n-- 1\u00aa definici\u00f3n de esOblongo\nesOblongo1 :: Integer -> Bool\nesOblongo1 n =\n  n == x * (x+1)\n  where x = round (sqrt (fromIntegral n))\n\n-- 2\u00aa definici\u00f3n de esOblongo\nesOblongo2 :: Integer -> Bool\nesOblongo2 n =\n  n `pertenece` oblongos3\n\npertenece :: Integer -> [Integer] -> Bool\npertenece x ys =\n  x == head (dropWhile (< x) ys)\n\n-- 1\u00aa definici\u00f3n de oblongos\noblongos1 :: [Integer]\noblongos1 = [n | n <- [0..]\n               , esOblongo1 n]\n\n-- 2\u00aa definici\u00f3n de oblongos\noblongos2 :: [Integer]\noblongos2 = filter esOblongo1 [0..]\n\n-- 3\u00aa definici\u00f3n de oblongos\noblongos3 :: [Integer]\noblongos3 = zipWith (*) [0..] [1..]\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Un n\u00famero oblongo es un n\u00famero que es el producto de dos n\u00fameros naturales consecutivos; es decir, n es un n\u00famero oblongo si existe un n\u00famero natural x tal que n = x(x+1). Por ejemplo, 42 es un n\u00famero oblongo porque 42 = 6 x 7. Definir las funciones esOblongo :: Integer -> Bool oblongos&#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":[5],"tags":[59,183,71,415,11,184,236,76],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/3405"}],"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=3405"}],"version-history":[{"count":3,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/3405\/revisions"}],"predecessor-version":[{"id":3442,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/3405\/revisions\/3442"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=3405"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=3405"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=3405"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}