It is 92. I first solved the 8 queens problem in 1979 (when I was boy :-), and for a while I puzzled over the fact that the number of solutions is not a multiple of 8. Then I realized that some of the solutions were rotationally and/or reflectionally symmetric. (For most solutions you get 8 variants by rotation or reflections, but for others you get less than 8.)
----- Original Message ----- From: Devon McCormick <[EMAIL PROTECTED]> Date: Saturday, April 5, 2008 10:01 Subject: Re: [Jgeneral] How readable is J? To: General forum <[email protected]> > There's an essay on the J-wiki about this - > http://www.jsoftware.com/jwiki/Essays/N_Queens_Problem - > though I think it > may have a mistake: aren't there 96 solutions if one counts all the > rotations and reflections of the basic 12 (not 92 as stated in > the essay)? > > There's also a Dyalog solution: > http://www.dyalog.dk/dfnsdws/n_queens.htm. I've seen the > one-liner but don't recall in which issue of Vector. > > On 4/5/08, Dan Bron <[EMAIL PROTECTED]> wrote: > > > > > familiarity with the symbolism is crucial. > > > > > > Absolutely (this is our common response to the "cryptic!" > accusation).> > > > > > And I have a one line APL function for printing out all > > > solutions for n queens on a board. > > > > > > Send that along. I'd like to give a shot. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
