On Mon, 25 Feb 2008, Carlo Hamalainen wrote:
On Mon, Feb 25, 2008 at 6:20 AM, [EMAIL PROTECTED] wrote:
Dirty, William. I can't believe you blame this on me -- that was all
Robert's fault. Anyway. I've co-opted Ajanki's framework, and have
rewritten the core of the search algorithm to
On Feb 25, 11:07 am, [EMAIL PROTECTED] wrote:
On Mon, 25 Feb 2008, Carlo Hamalainen wrote:
On Mon, Feb 25, 2008 at 6:20 AM, [EMAIL PROTECTED] wrote:
Dirty, William. I can't believe you blame this on me -- that was all
Robert's fault. Anyway. I've co-opted Ajanki's framework, and
I would also suggest to go that way since we can then merge the ticket
dependent on it. Once we have the correctly, but not blazingly fast
version in Sage we can always switch to the C++ version as it is
convenient for the integrators.
+1 -- all those lovely doctests will not go to waste :)
On Sat, 23 Feb 2008, William Stein wrote:
On Sat, Feb 23, 2008 at 12:46 PM, [EMAIL PROTECTED] wrote:
On Sat, 23 Feb 2008, Carlo Hamalainen wrote:
On Fri, Feb 22, 2008 at 8:55 PM, [EMAIL PROTECTED] wrote:
Arguments for including Ajanki's code:
1) It's the only Python
;
Subjectnbsp;nbsp; Re: [sage-devel] Re: exact cover problem
William Stein [EMAIL PROTECTED]
02/22/2008 12:49 PM PST
font size=-1/font
On Fri, Feb 22, 2008 at 12:04 PM, Jason Grout
[EMAIL PROTECTED] wrote
On Fri, Feb 22, 2008 at 8:55 PM, [EMAIL PROTECTED] wrote:
Arguments for including Ajanki's code:
1) It's the only Python implementation of DLX I've seen.
2) I emailed the author, who happily added the or later bit after the
GPL2
3) With my Sage Matrix - DLXMatrix code (plus
On Sat, 23 Feb 2008, Carlo Hamalainen wrote:
On Fri, Feb 22, 2008 at 8:55 PM, [EMAIL PROTECTED] wrote:
Arguments for including Ajanki's code:
1) It's the only Python implementation of DLX I've seen.
2) I emailed the author, who happily added the or later bit after the
GPL2
On Sat, Feb 23, 2008 at 12:46 PM, [EMAIL PROTECTED] wrote:
On Sat, 23 Feb 2008, Carlo Hamalainen wrote:
On Fri, Feb 22, 2008 at 8:55 PM, [EMAIL PROTECTED] wrote:
Arguments for including Ajanki's code:
1) It's the only Python implementation of DLX I've seen.
2) I
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 this context I think that binary means all the entries are 1s and zeros.
But when you look for a set of rows that add up to [1,1,1,...], you don't
consider 1+1=0. This makes sense when you want only one 1 to appear in each
column, which is a natural requirement, and makes the problem much
On Fri, Feb 22, 2008 at 12:50 PM, David Harvey
[EMAIL PROTECTED] wrote:
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,
Just a technical note: Mod 2 matrices are not the natural way to think
about adjacency matrices (I learned this the hard way) - the entry is
actually better thought of as the number of paths of length one from
one vertex to another. That way taking nth powers of the matrices
counts the number of
If it is an NP-complete problem, presumably it asks whether such a set
of rows exists, not that you find one.
Bill.
On 22 Feb, 21:32, Robert Miller [EMAIL PROTECTED] wrote:
Just a technical note: Mod 2 matrices are not the natural way to think
about adjacency matrices (I learned this the hard
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