Given a 5x5 chess board, place the fewest number of queens possible on the board such that no queens are under attack but every other space is under attack.

I am going to say 5... This is how they are arranged:
o means an empty square, x means a queen

o x o o o
o o o x o
x o o o o
o o x o o
o o o o x

No queens can be captured, but all squares are covered.
There is more than one way to arrange them on the board (for instance, rotate the board 90, 180, or 270 degrees), but I do believe that the number is 5.

Posted by Matt on 2004-12-08 02:31:02