can_turn
static boolean can_turn(short, short);
if ((dir != 'h') && can_turn(crow, ccol + 1)) {
if ((dir != 'l') && can_turn(crow, ccol - 1)) {
if ((dir != 'k') && can_turn(crow + 1, ccol)) {
if ((dir != 'j') && can_turn(crow - 1, ccol)) {