{"id":811,"date":"2014-12-16T06:00:58","date_gmt":"2014-12-16T04:00:58","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=811"},"modified":"2014-12-27T21:03:14","modified_gmt":"2014-12-27T19:03:14","slug":"representaciones-de-matrices","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/representaciones-de-matrices\/","title":{"rendered":"Representaciones de matrices"},"content":{"rendered":"<h4>Enunciado<\/h4>\n<pre lang=\"text\">\n-- Las matrices se pueden representar de distintas formas. Por ejemplo,\n-- la matriz\n--    |7 5 6|\n--    |1 9 4|\n-- se puede representar como la terna\n--    ([7,5,6,1,9,4],2,3)\n-- (donde la primera componente es la lista de los elementos de la\n-- matriz, la segunda es su n\u00famero de filas y la tercera es su n\u00famero de\n-- columnas) y tambi\u00e9n se puede representar como una lista de listas\n--    [[[7,5,6],[1,9,4]]\n-- (donde cada elemento es una de las filas de la matriz).\n-- \n-- Definir las funciones\n--    ternaAlistas :: ([a],Int,Int) -> [[a]]\n--    listasAterna :: [[a]] -> ([a],Int,Int) \n-- tales que ternaAlistas pase de la primera representaci\u00f3n a la\n-- segunda y listasAterna pase de la segunda a la primera. Por ejemplo, \n--    ternaAlistas ([7,5,6,1,9,4],2,3)  ==  [[7,5,6],[1,9,4]]\n--    listasAterna [[7,5,6],[1,9,4]]    ==  ([7,5,6,1,9,4],2,3)\n--    ternaAlistas ([7,5,6,1,9,4],3,2)  ==  [[7,5],[6,1],[9,4]]\n--    listasAterna [[7,5],[6,1],[9,4]]  ==  ([7,5,6,1,9,4],3,2)\n<\/pre>\n<h4>Soluciones<\/h4>\n<pre lang=\"haskell\">\nternaAlistas :: ([a],Int,Int) -> [[a]]\nternaAlistas (xs,n,m) = aux xs\n    where aux [] = []\n          aux xs = take m xs : aux (drop m xs)\n\nlistasAterna :: [[a]] -> ([a],Int,Int) \nlistasAterna xss = (concat xss, length xss, length (head xss))\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Enunciado &#8212; Las matrices se pueden representar de distintas formas. Por ejemplo, &#8212; la matriz &#8212; |7 5 6| &#8212; |1 9 4| &#8212; se puede representar como la terna &#8212; ([7,5,6,1,9,4],2,3) &#8212; (donde la primera componente es la lista de los elementos de la &#8212; matriz, la segunda es su n\u00famero de filas y&#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":[12,46,71,28,6,47],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/811"}],"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=811"}],"version-history":[{"count":3,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/811\/revisions"}],"predecessor-version":[{"id":880,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/811\/revisions\/880"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=811"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=811"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=811"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}