{"id":4425,"date":"2018-12-17T06:00:37","date_gmt":"2018-12-17T04:00:37","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=4425"},"modified":"2018-12-24T07:18:38","modified_gmt":"2018-12-24T05:18:38","slug":"intercambio-de-la-primera-y-ultima-columna-de-una-matriz","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/intercambio-de-la-primera-y-ultima-columna-de-una-matriz\/","title":{"rendered":"Intercambio de la primera y \u00faltima columna de una matriz"},"content":{"rendered":"<p>Las matrices se pueden representar mediante listas de listas. Por ejemplo, la matriz<\/p>\n<pre lang=\"text\">\n   8 9 7 6\n   4 7 6 5\n   3 2 1 8\n<\/pre>\n<p>se puede representar por la lista<\/p>\n<pre lang=\"text\">\n   [[8,9,7,6],[4,7,6,5],[3,2,1,8]]\n<\/pre>\n<p>Definir la funci\u00f3n<\/p>\n<pre lang=\"text\">\n   intercambia :: [[a]] -> [[a]]\n<\/pre>\n<p>tal que (intercambia xss) es la matriz obtenida intercambiando la primera y la \u00faltima columna de xss. Por ejemplo,<\/p>\n<pre lang=\"text\">\n   \u03bb> intercambia [[8,9,7,6],[4,7,6,5],[3,2,1,8]]\n   [[6,9,7,8],[5,7,6,4],[8,2,1,3]]\n<\/pre>\n<h4>Soluciones<\/h4>\n<pre lang=\"haskell\">\nintercambia :: [[a]] -> [[a]]\nintercambia = map intercambiaL\n\n-- (intercambiaL xs) es la lista obtenida intercambiando el primero y el\n-- \u00faltimo elemento de xs. Por ejemplo,\n--    intercambiaL [8,9,7,6]  ==  [6,9,7,8]\nintercambiaL :: [a] -> [a]\nintercambiaL xs =\n  last xs : tail (init xs) ++ [head xs]\n<\/pre>\n<h4>Pensamiento<\/h4>\n<blockquote><p>\n\u00ab\u00a1Que dif\u00edcil es,<br \/>\ncuando todo baja<br \/>\nno bajar tambi\u00e9n!\u00bb <\/p>\n<p>Antonio Machado\n<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>Las matrices se pueden representar mediante listas de listas. Por ejemplo, la matriz 8 9 7 6 4 7 6 5 3 2 1 8 se puede representar por la lista [[8,9,7,6],[4,7,6,5],[3,2,1,8]] Definir la funci\u00f3n intercambia :: [[a]] -> [[a]] tal que (intercambia xss) es la matriz obtenida intercambiando la primera y la \u00faltima columna&#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":[71,285,134,10,11,45],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/4425"}],"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=4425"}],"version-history":[{"count":7,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/4425\/revisions"}],"predecessor-version":[{"id":4462,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/4425\/revisions\/4462"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=4425"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=4425"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=4425"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}