递归获取树的所有孩子

class TreeNode:
    def __init__(self, value):
        self.value = value
        self.children = []

def get_all_children(node):
    if not node:
        return []
    
    result = [node.value]
    for child in node.children:
        result.extend(get_all_children(child))
    
    return result

# 示例树结构
root = TreeNode('A')
node_b = TreeNode('B')
node_c = TreeNode('C')
node_d = TreeNode('D')
node_e = TreeNode('E')

root.children.append(node_b)
root.children.append(node_c)
node_b.children.append(node_d)
node_b.children.append(node_e)

# 获取所有孩子
all_children = get_all_children(root)
print(all_children)  # 输出: ['A', 'B', 'D', 'E', 'C']