题解 | #在二叉树中找到两个节点的最近公共祖先#

牛客这里题目经常不明确，节点和节点值应当明显区分一下
给的输入例子，也有时候明明是字符串型'1'，输入中显示给的却是 1

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

#
# 
# @param root TreeNode类 
# @param o1 int整型 
# @param o2 int整型 
# @return int整型
#
class Solution:
    def lowestCommonAncestor(self , root , o1 , o2 ):
        # write code here
        def haschild(root, o1, o2):
            if root is None or self.ancestor is not None:
                return False
            ans = root.val == o1 or root.val == o2
            lson = haschild(root.left, o1, o2)
            rson = haschild(root.right, o1, o2)
            if (lson and rson) or (ans and (lson or rson)):
                self.ancestor = root.val
                return 
            return ans or lson or rson
        self.ancestor = None
        haschild(root, o1, o2)
        return self.ancestor