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
