CASE 1:

5 1 2        1 2 3
6 3 *        4 5 6
4 7 8        7 8 *

initial      goal
state

----------

CASE 2:

5 2 *        1 2 3
6 1 3        4 5 6 
4 7 8        7 8 *

initial      goal
state

----------

CASE 3:

1 2 3        1 2 3
* 8 7        4 5 6
6 5 4        7 8 *

initial      goal
state