You have a square 5 x 5 board with four rooks in the corners:
|
Note: for reference, assume the rooks are labeled A, B, C, D as follows:
A B
C D
|
You can move the rooks horizontally or vertically. The only problem is that when you move a rook, it will keep going in the same direction until it hits another rook or the edge of the board.
You want to move a rook into the darkened square on the board.
How can this be done in no more than 10 moves?
INITIAL POSITION:
A...B
.....
.....
.....
C...D
1:
A...B
C....
.....
.....
....D
2:
A....
C....
.....
....B
....D
3:
....A
C....
.....
....B
....D
4:
.....
C....
....A
....B
....D
5:
.....
C....
....A
B....
....D
6:
.....
C....
....A
B....
D....
7:
.....
C....
B...A
.....
D....
8:
.....
C....
...BA
.....
D....
9:
.....
C....
D..BA
.....
.....
10
.....
C....
..DBA
.....
.....
solution (spoiler()
