tag:blogger.com,1999:blog-9182705499898252496.post6997241069329976275..comments2011-12-15T17:04:32.023-05:00Bill the Lizardhttp://www.blogger.com/profile/09810099093752485841noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-9182705499898252496.post-75904473687427023652011-12-15T17:04:32.023-05:002011-12-15T17:04:32.023-05:00My solution is even simpler:<br /><br />(define (* a b)<br /> (cond ((= b 0) 0)<br /> ((even? b) (* (double a) (halve b)))<br /> (else (+ a (* a (- b 1))))))mgrhttp://www.blogger.com/profile/01484444354209264861noreply@blogger.comtag:blogger.com,1999:blog-9182705499898252496.post-23690008103854130842011-10-31T00:37:12.552-04:002011-10-31T00:37:12.552-04:00one could even go as far as checking which of the two numbers is smaller and use that as the iterator. it&#39;s a nice optimization.alinrusnoreply@blogger.comtag:blogger.com,1999:blog-9182705499898252496.post-2750600487742363042011-09-05T16:01:41.271-04:002011-09-05T16:01:41.271-04:00hmmnnn...the fast-multiply is just like having a code of x*y in short...Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9182705499898252496.post-89398176827100068842010-01-14T00:59:06.128-05:002010-01-14T00:59:06.128-05:00Ahh :P ..my bad then. Not that much of an expert in English. Portuguese here :) Yeah, halving surely exists. Just automatically wanted that to be a misspelled word as an internet blog (flame) reader :P<br /><br />Keep up the good work.mwmhttp://www.blogger.com/profile/05612318619217836452noreply@blogger.comtag:blogger.com,1999:blog-9182705499898252496.post-30106766987774960342010-01-14T00:44:00.660-05:002010-01-14T00:44:00.660-05:00mwm,<br />Those are great warm-up exercises. I love problems that make you re-implement familiar operations in ways you might not have thought about before (at least not for some time). They&#39;re great for students because the problem is well understood, so they can focus on the solution.<br /><br />I&#39;m pretty sure &quot;halving&quot; is the right spelling for the word meaning &quot;to divide in half.&quot; It&#39;s not getting picked up by my spell checker, at least. Anyway, at least it got you to comment. :)Bill the Lizardhttp://www.blogger.com/profile/09810099093752485841noreply@blogger.comtag:blogger.com,1999:blog-9182705499898252496.post-90151787809056066422010-01-13T22:44:52.970-05:002010-01-13T22:44:52.970-05:00Btw, &quot;halving&quot; on 1st paragraph. Misspelling already for the blog hits? :Pmwmhttp://www.blogger.com/profile/05612318619217836452noreply@blogger.comtag:blogger.com,1999:blog-9182705499898252496.post-47772219516759549062010-01-13T22:43:16.561-05:002010-01-13T22:43:16.561-05:00I challenge you to make procedures only with &quot;+1&quot;, &quot;-1&quot; and &quot;zero?&quot; procedures already made, that adds 1, subs 1 and checks if it&#39;s zero to any number, respectively.<br /><br />Make &quot;sum&quot;, &quot;sub&quot; &quot;mult&quot; and &quot;div&quot;.<br />That was my &quot;Programming Fundamentals&quot; course first exercises on Scheme :Pmwmhttp://www.blogger.com/profile/05612318619217836452noreply@blogger.com