Method selection

mcts_math/agents/mcts.py:67–77

(self)

            self.expansion_evaluation_backpropagation(node)

    def selection(self) -> Optional[Type[MCTSNode]]:
        node = self.root
        # while node.has_children() or node.is_terminal:     # for some purpose, but i forget it.
        while node.has_children() and not node.is_terminal:  # for mcts, it should be like this
            next_node = self.select_child(node)     # To encourage exploration, select from non-terminal children
            if next_node is None:                   # if None，it mean all children are terminal
                node.is_terminal = True
                break
            node = next_node
    
        return None if node.is_terminal else node

    def select_child(self, node: Type[MCTSNode]) -> Optional[Type[MCTSNode]]:
        # TODO: implement multi-strategy