The goal is to place eight queens on a chess board in manner
that no queen is threaten by the others.
According to the chess rules ,a queen controls the row, column
and diagonals that pass through its square.
The application offers you different sizes of board from 6 x 6
up to 9 x 9 .The default is 8 x 8.
For playing then drag a queen on the board and drop it on a free square.
You can play with a timer for that click the "on" button of the timer and set the wanted time.
For checking the solutions then click the "solution" button and after the message click any square
then the application will display with animation the solution.