This is a bit off-topic (though it is about N-queens) but I've long wanted to ask people if an idea I had once is a well-known one. It once occurred to me that solutions to N-rooks can be viewed as linear transformations that correspond to permutations of a vector. So, then I wondered to what sort of transformations solutions to N-queens correspond. I'll leave a gap in case anyone wants to think about it...
Okay, N-queens solutions correspond to transformations in which no two entries in the permuted vector are the same distance apart as they were before. This leads to a simple algorithm for finding solutions. Fill a vector with the digits 1 to veclen, generate permutations, and see if the difference between any two element indices is the same as the difference between their contents. You can then easily reverse engineer the board. Is this well known? Thanks, --Jerry Jackson -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
