I was not attentive reading this problem's situations, so I did not pay enough attention to the fact, that EXACTLY three queens should be rearranged. My first solution did count situations, when only two queens were moved... It produced a WA (-:

Well, i think that you can simulate the 2 movements rearrangement, with exactly 3 queens, i think this problem statement should be clarified in that sense.
If you have a queen "a" in position 0 0, another "b" in position 1 1 and a last "c" in position 2 2... in a N=3 chessboard, you can put a in position 1 2, b in position 0 0 and c in position 2 1. Its like a 2 queens movement, but i moved 3 queens.

This test is incorrect because queen "a" attacks "b"

Edited by author 15.03.2010 20:52

This hint has helped me to AC.thx