{"id":2655,"date":"2016-12-06T06:00:12","date_gmt":"2016-12-06T04:00:12","guid":{"rendered":"http:\/\/www.glc.us.es\/~jalonso\/exercitium\/?p=2655"},"modified":"2016-12-13T07:34:49","modified_gmt":"2016-12-13T05:34:49","slug":"sin-ceros-finales","status":"publish","type":"post","link":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/sin-ceros-finales\/","title":{"rendered":"Sin ceros finales"},"content":{"rendered":"<p>Definir la funci\u00f3n<\/p>\n<pre lang=\"text\">\n   sinCerosFinales :: Int -> Int\n<\/pre>\n<p>tal que (sinCerosFinales n) es el n\u00famero obtenido eliminando los ceros finales de n. Por ejemplo,<\/p>\n<pre lang=\"text\">\n   sinCerosFinales 104050     == 10405\n   sinCerosFinales 960000     == 96\n   sinCerosFinales 100050     == 10005\n   sinCerosFinales (-10050)   == -1005\n   sinCerosFinales 12         == 12\n   sinCerosFinales 0          == 0\n<\/pre>\n<p>Comprobar con QuickCheck que, para cualquier n\u00famero entero n,<\/p>\n<pre lang=\"text\">\n   sinCerosFinales (sinCerosFinales n) == sinCerosFinales n\n<\/pre>\n<h4>Soluciones<\/h4>\n<pre lang=\"haskell\">\nimport Test.QuickCheck\n\n-- 1\u00aa soluci\u00f3n\nsinCerosFinales :: Int -> Int\nsinCerosFinales 0 = 0\nsinCerosFinales n\n  | r \/= 0    = n\n  | otherwise = sinCerosFinales q  \n  where (q,r) = quotRem n 10\n\n-- 2\u00aa soluci\u00f3n\nsinCerosFinales2 :: Int -> Int\nsinCerosFinales2 0 = 0\nsinCerosFinales2 n =\n  read (reverse (dropWhile (=='0') (reverse (show n))))\n\n-- 3\u00aa soluci\u00f3n\nsinCerosFinales3 :: Int -> Int\nsinCerosFinales3 0 = 0\nsinCerosFinales3 n =\n  (read . reverse . dropWhile (== '0') . reverse . show) n\n\n-- 4\u00aa soluci\u00f3n\nsinCerosFinales4 :: Int -> Int\nsinCerosFinales4 0 = 0\nsinCerosFinales4 n =\n  read . reverse . dropWhile (== '0') . reverse . show $ n\n\n-- La propiedad es\nprop_sinCerosFinales :: Int -> Bool\nprop_sinCerosFinales n =\n  sinCerosFinales (sinCerosFinales n) == sinCerosFinales n\n\n-- 5\u00aa soluci\u00f3n\nsinCerosFinales5 :: Int -> Int\nsinCerosFinales5 0 = 0\nsinCerosFinales5 n = until (\\x -> mod x 10 \/= 0) (`div` 10) n\n\n-- La comprobaci\u00f3n es\n--    \u03bb> quickCheck prop_sinCerosFinales\n--    +++ OK, passed 100 tests.\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Definir la funci\u00f3n sinCerosFinales :: Int -> Int tal que (sinCerosFinales n) es el n\u00famero obtenido eliminando los ceros finales de n. Por ejemplo, sinCerosFinales 104050 == 10405 sinCerosFinales 960000 == 96 sinCerosFinales 100050 == 10005 sinCerosFinales (-10050) == -1005 sinCerosFinales 12 == 12 sinCerosFinales 0 == 0 Comprobar con QuickCheck que, para cualquier n\u00famero&#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":[4],"tags":[59,11,254,95,6,32,33,146],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/2655"}],"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=2655"}],"version-history":[{"count":5,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/2655\/revisions"}],"predecessor-version":[{"id":2689,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/posts\/2655\/revisions\/2689"}],"wp:attachment":[{"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/media?parent=2655"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/categories?post=2655"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.glc.us.es\/~jalonso\/exercitium\/wp-json\/wp\/v2\/tags?post=2655"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}