{"id":4760,"date":"2019-02-25T06:00:40","date_gmt":"2019-02-25T04:00:40","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=4760"},"modified":"2019-03-04T07:40:26","modified_gmt":"2019-03-04T05:40:26","slug":"inserciones-en-una-lista-de-listas","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/inserciones-en-una-lista-de-listas\/","title":{"rendered":"Inserciones en una lista de listas"},"content":{"rendered":"<p>Definir la funci\u00f3n<\/p>\n<pre lang=\"text\"> \n   inserta :: a -> [[a]] -> [[[a]]]\n<\/pre>\n<p>tal que (inserta x yss) es la lista obtenida insertando x en cada uno de los elementos de yss. Por ejemplo,<\/p>\n<pre lang=\"text\"> \n   \u03bb> inserta 1 [[2,3],[4],[5,6,7]]\n   [[[1,2,3],[4],[5,6,7]],[[2,3],[1,4],[5,6,7]],[[2,3],[4],[1,5,6,7]]]\n   \u03bb> inserta 'a' [\"hoy\",\"es\",\"lunes\"]\n   [[\"ahoy\",\"es\",\"lunes\"],[\"hoy\",\"aes\",\"lunes\"],[\"hoy\",\"es\",\"alunes\"]]\n<\/pre>\n<h4>Soluciones<\/h4>\n<pre lang=\"haskell\">\n-- 1\u00aa soluci\u00f3n\ninserta :: a -> [[a]] -> [[[a]]]\ninserta _ []       = []\ninserta x (ys:yss) = ((x:ys):yss) : [ys : zs | zs <- inserta x yss] \n\n-- 2\u00aa soluci\u00f3n\ninserta2 :: a -> [[a]] -> [[[a]]]\ninserta2 _ []       = []\ninserta2 x (ys:yss) = ((x:ys):yss) : map (ys:) (inserta2 x yss) \n<\/pre>\n<h4>Pensamiento<\/h4>\n<blockquote><p>\n&#8230; De la mar al percepto,<br \/>\ndel percepto al concepto,<br \/>\ndel concepto a la idea<br \/>\n&#8212; \u00a1oh, la linda tarea! &#8212;<br \/>\nde la idea a la mar.<br \/>\n\u00a1Y otra vez al empezar!<\/p>\n<p>Antonio Machado\n<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>Definir la funci\u00f3n inserta :: a -> [[a]] -> [[[a]]] tal que (inserta x yss) es la lista obtenida insertando x en cada uno de los elementos de yss. Por ejemplo, \u03bb> inserta 1 [[2,3],[4],[5,6,7]] [[[1,2,3],[4],[5,6,7]],[[2,3],[1,4],[5,6,7]],[[2,3],[4],[1,5,6,7]]] \u03bb> inserta &#8216;a&#8217; [\u00abhoy\u00bb,\u00bbes\u00bb,\u00bblunes\u00bb] [[\u00abahoy\u00bb,\u00bbes\u00bb,\u00bblunes\u00bb],[\u00abhoy\u00bb,\u00bbaes\u00bb,\u00bblunes\u00bb],[\u00abhoy\u00bb,\u00bbes\u00bb,\u00bbalunes\u00bb]] Soluciones &#8212; 1\u00aa soluci\u00f3n inserta :: a -> [[a]] -> [[[a]]] 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":[5],"tags":[8,11,6],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/4760"}],"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=4760"}],"version-history":[{"count":3,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/4760\/revisions"}],"predecessor-version":[{"id":4786,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/4760\/revisions\/4786"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=4760"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=4760"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=4760"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}