On 09/03/2011 17:55, Bill Hart wrote: > There is the C function mpz_sizeinbase. If you do it in base 2 it will > extremely efficiently tell you the bit length. Your algorithm will > actually be O(n^2) time, whereas mpz_sizeinbase for base a power of 2 > is O(1).
Many thanks - mpx_sizeinbase() with mpz_class::get_mpz_t() looks a lot more sane as an implementation than my prototype... even when I correct the assert to be "BOOST_ASSERT(number>0);" - as I originally intended. I found mpz_class::get_prec() - though I could neither make sense of the returned values, nor find its documentation. While mpz_sizeinbase() is obviously far more efficient than my reference implementation - is it as efficient as possible - given that I only care about the degenerate binary case? -- You received this message because you are subscribed to the Google Groups "mpir-devel" group. To post to this group, send email to mpir-devel@googlegroups.com. To unsubscribe from this group, send email to mpir-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/mpir-devel?hl=en.
