Find Free Cells

To define a uniform interface between the free cells of a board and the different players the function freeCells() is used. Every cell which is free is listed in a list with its Y and X coordinates,

 
-->W4
 W4  =
 
!_  O  _  !
!         !
!X  X  _  !
!         !
!_  _  _  !

 
-->show=0,[CLst]=freeCells(W4,show)

 CLst  =
 
    1.    1.  
    1.    3.  
    2.    3.  
    3.    1.  
    3.    2.  
    3.    3.