def run(self):
if self.mct == None:
# if new tree then initialize that it came from the opposite player
self.mct = Tree(switch_turns(self.turn))
else:
# if the tree exists look for the node if it contains that
children = self.mct.get_root().get_children()
if len(children) != 0:
contained = False
node = children[0]
for n in children:
if n.get_move() == self._cloned_board.get_previous_move():
contained = True
node = n
if contained:
self.mct.set_root(node)
else:
# otherwise initialize new tree
self.mct = Tree(switch_turns(self.turn))
else:
# otherwise initialize new tree
self.mct = Tree(switch_turns(self.turn))
start_time = current_milli_time()
while current_milli_time() - start_time < self.timeout - self.before:
self._cloned_board = clone(
UltimateTicTacToe(board=self.board, last_turn=self.last_turn))
self.roll_out(self.expansion(self.selection(self.mct.get_root())))
return self.choose_best_next_move()
def roll_out(self, node):
# first approach, random sample to see
current_simulation_turn = switch_turns(node.get_turn())
while not self._cloned_board.is_game_done():
moves = self._cloned_board.get_free_moves()
move = choice(moves)
self.play_cloned_board(move, current_simulation_turn)
current_simulation_turn = switch_turns(current_simulation_turn)
if self._cloned_board.get_winner() == None:
self.backpropogate(GameState.DRAW, node)
else:
self.backpropogate(
GameState.LOSE if node.get_turn() == current_simulation_turn
else GameState.WIN, node)
def add_child(self, move):
child = Node(move=move, parent=self, turn=switch_turns(self._turn))
self._children.append(child)
return child