On Feb 22, 2008, at 3:49 PM, William Stein wrote:
> > On Fri, Feb 22, 2008 at 12:04 PM, Jason Grout > <[EMAIL PROTECTED]> wrote: >> >> [EMAIL PROTECTED] wrote: >>> I've found a nice implementation of the DLX algorithm, which >>> "quickly" solves the NP-Complete exact cover problem. For those >>> who aren't in Seattle and haven't heard me blathering on and on >>> and on and on about how awesome DLX is... >>> >>> Let M be a binary matrix. An exact cover is a subset of the rows >>> of the matrix who sum (exactly) to the vector 1,1,...,1. >>> > > Isn't that exactly the same thing as solving > > M*x = [1,...,1], > > over GF(2)? I think it's probably not mod 2. david --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
