Re: [boost] big_integer numeric error

From: Richard Peters (r.a.peters_at_[hidden])
Date: 2004-05-15 08:18:51

I have found the error, it's in the addition algorithm, line 93,
default_impl.hpp. Swap these two lines:
    std::size_t n = std::min(u.size(), v.size());
    w.resize(m, 0);
so that it reads
    w.resize(m, 0);
    std::size_t n = std::min(u.size(), v.size());
then it all works correctly again (for now :) )

I'll try to come up with faster multiplication and division algorithms in
the upcoming week, I'll upload a version of the library with the above error
corrected when the faster versions of the algorithms are implemented.

The division algorithm didn't contain the bugs of Knuth, I had already found
them and gave a correct implementation. (well, at least with respect to
_those_ bugs).

best regards,

Richard Peters

From: "Joel Young" <jdy_at_[hidden]>
> > I believe there is a numeric error in big_integer_0.3.  I am working
> > to isolate it to a single operation.
>
> Ok.  I have it isolated to a piece of test code: