python二叉树如何查找一个节点的父节点的代码

你好呀！很高兴为您服务~

Regarding your question, here's the Python code to find the parent node of a node in a binary tree:

class TreeNode:
    def __init__(self, val):
        self.val = val
        self.left = None
        self.right = None
        self.parent = None # assume parent node is also stored in tree node

def find_parent(root, node):
    if root is None:
        return None
    if root.left == node or root.right == node:
        return root
    left_result = find_parent(root.left, node)
    if left_result:
        return left_result
    right_result = find_parent(root.right, node)
    if right_result:
        return right_result

# example usage:
root = TreeNode(1)
root.left = TreeNode(2)
root.left.parent = root
root.right = TreeNode(3)
root.right.parent = root
node = root.right
print(find_parent(root, node).val) # output: 1

Hope this helps! Let me know if you have any other questions.