enum{	Pass = -2,	White,	Empty,	Black,	Ko,	Marked = 10,	Maxgobansize = 19}; extern int sgoban;extern int turn;extern int npass;extern int nblackcaptured;extern int nwhitecaptured;extern int ko;extern int isgameover;extern int goban[Maxgobansize * Maxgobansize];extern int group[Maxgobansize * Maxgobansize]; /* group[coord] */extern int liberty[Maxgobansize * Maxgobansize]; /* liberties[group] */ void initgoban(int);int drawgoban(void);int px2move(Point);int playmove(int);int undomove(int);int capture(int);