在树的节点上添加一个属性来表示该节点的父节点，然后利用递归函数遍历整棵树，将所有节点和其关联的父节点储存在字典中。最后根据某个节点找到它的后代节点列表。

代码示例：

class Node: def init(self, value, parent=None): self.value = value self.parent = parent self.children = []

def add_child(self, node):
    self.children.append(node)
    node.parent = self

def traverse_tree(self):
    # dictionary to store nodes and their corresponding parents
    visited = {self: None}

    # recursive function to traverse tree
    def recursion(node):
        for child in node.children:
            visited[child] = node
            recursion(child)

    recursion(self)

    # get descendants of a node
    def get_descendants(node):
        descendants = []
        for child in node.children:
            if child in visited:
                descendants.append(child)
                descendants.extend(get_descendants(child))
        return descendants

    return visited, get_descendants

create a sample tree

root = Node(1) node2 = Node(2) node3 = Node(3) node4 = Node(4) node5 = Node(5) node6 = Node(6)

root.add_child(node2) root.add_child(node3) node2.add_child(node4) node2.add_child(node5) node4.add_child(node6)

traverse the tree and get descendants

visited, get_descendants = root.traverse_tree()

print all nodes and their corresponding parents

for node, parent in visited.items(): print(node.value, parent.value if parent else None)

get descendants of node 2

print([node.value for node in get_descendants(node2)]) # [4, 5, 6]