如何对树表中每个节点的所有子孙值求和

# 定义树节点类
class TreeNode:
    def __init__(self, value):
        self.value = value
        self.children = []

# 递归计算每个节点的所有子孙值之和
def sum_of_descendants(node):
    # 如果节点没有子节点，直接返回节点的值
    if not node.children:
        return node.value
    
    # 递归计算子节点的值之和
    descendants_sum = sum(sum_of_descendants(child) for child in node.children)
    
    # 返回节点值和子节点值之和
    return node.value + descendants_sum

# 创建树结构
root = TreeNode(1)
node2 = TreeNode(2)
node3 = TreeNode(3)
node4 = TreeNode(4)
node5 = TreeNode(5)
node6 = TreeNode(6)

root.children = [node2, node3]
node2.children = [node4, node5]
node3.children = [node6]

# 求解树表中每个节点的所有子孙值之和
result = sum_of_descendants(root)
print(result)  # 输出：21