On Fri, Nov 11, 2011 at 1:23 AM, Walter Prins <wpr...@gmail.com> wrote: > Hi, > > On 10 November 2011 16:23, lina <lina.lastn...@gmail.com> wrote: >> >> def LongestCommonSubstring(S1, S2): >> M = [[0]*(1+len(S2)) for i in range(1+len(S1))] >> longest, x_longest = 0, 0 >> for x in range(1,1+len(S1)): >> for y in range(1,1+len(S2)): >> M[x][y] = M[x-1][y-1]+1 >> if M[x][y] > longest: >> longest = M[x][y] >> x_longest = x >> else: >> M[x][y] = 0 >> return S1[x_longest-longest:x_longest] > > This is not the same as the implementation given on wikibooks.... Have you > tried reverting your changes and using the coe that was given on the site > exactly as is? (I assume not, and if so, why not?) I used python3, it showed me NameError: name 'xrange' is not defined so I made a little changes, before I even worried I might forget to import some modules to make the xrange work. > > (Specifically, I notice most the likely culprit is a missing if statement > just below the "for y in range..." line that's been deleted....) Thanks for that. adding this missing line, works. I am still lack of understanding how the code works, so made above mistake. > >> >> The results isn't right. > > Yes. You appear to have introduced a bug by not using the same code as what > was given on the wiki page. (Why did you modify the code and then when the > modified code didn't work assume the original solution was broken instead of > checking first and/or suspecting that your changes may have broken it?) Sorry. I did not assume the original code was broken, might a little unconsciously worry it might be out of date at that time. I checked by eyes, bad, and did not check carefully.
Thanks with best regards, > > Walte > > > _______________________________________________ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor > > _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
