Write an application that calculates and shows a possible solution
for placing 8 chess queens on a chessboard in a way that no queen
threatens another.
A chessboard has 8x8 squares, and a chess queen threatens
every other piece that sits in a square in a straigth line
north, northeast, east, southeast,south, southwest, west or
northwest of her.
What is tested: graph searching, path finding, backtracking, non-trivial algorithms.
Contributed by Nils M Holm , nmh at despammed.com