Ha, caught me being lazy. For loops like repeat with i = 1 to fld 1
there is (almost) no difference -- the field gets referenced one time at the start and that's it. But since I was lazy about how a loop with "step 2" in it would exit, I was slower. Thanks! gc On Wed, Nov 11, 2015 at 7:34 AM, Peter M. Brigham <pmb...@gmail.com> wrote: > There may be other factors more important for speed, but one thing is to > avoid having to access the contents of a field 1.5 billion times, by > putting fld 1 into a variable, say "maxNbr", and then doing > > repeat until i > maxNbr… > > -- Peter > > Peter M. Brigham > pmb...@gmail.com > http://home.comcast.net/~pmbrig > > > On Nov 11, 2015, at 2:45 AM, Geoff Canyon wrote: > > > I'm playing with a challenge to calculate the sum of the primes less than > > 3,000,000,000 > > > > So far I have this, which gets the job done for the primes up to about a > > billion, but then dies (the whole app) without even a dialog. It's also > not > > very fast. It would probably take an hour or two to finish. > > > > Any suggestions for efficiency or non-crashed-ness? > > > > function bAdd x,y > > -- adds two positive numbers of arbitrary length > > put 0 into c > > repeat with i = 14 to max(length(x),length(y)) > > add char -i to 13 - i of x + char -i to 13 - i of y to c > > put char -14 to -1 of c before r > > delete char -14 to -1 of c > > end repeat > > return c & r > > end bAdd > > > > on mouseUp > > put 2 into T > > put 0 into S > > put 3 into i > > repeat until i > fld 1 -- fld 1 contains 3000000000 > > if P[i] is empty then > > put bAdd(i,T) into T > > put i & comma after P[i*3] > > else > > repeat for each item x in P[i] > > put x & comma after P[i + x + x] > > end repeat > > delete P[i] > > end if > > if the seconds > S then > > put the seconds into S > > put i && T into fld 2 > > unlock screen > > lock screen > > end if > > add 2 to i > > end repeat > > put i && T into fld 2 > > end mouseUp > > _______________________________________________ > > use-livecode mailing list > > use-livecode@lists.runrev.com > > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > > http://lists.runrev.com/mailman/listinfo/use-livecode > > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode > _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
