On Wed, 19 May 2010 21:58:04 +0200, superpollo <ute...@esempio.net> wrote: > ... how many positive integers less than n have digits that sum up to m:
If it's important for the function to execute quickly for large n, you might get a useful speedup by testing only every ninth integer, since any two integers whose digits add up to m differ by a multiple of 9. A simple application of this observation would be to test range( m % 9, n, 9 ) rather than testing range( 1, n ). I suspect that further applications of number theory would provide additional, substantial speedups, but this wanders away from the subject of Python. -- To email me, substitute nowhere->spamcop, invalid->net. -- http://mail.python.org/mailman/listinfo/python-list
