题解 | #在二叉树中找到两个节点的最近公共祖先#

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
#
# 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
#
#
# @param root TreeNode类
# @param o1 int整型
# @param o2 int整型
# @return int整型
#
class Solution:
    def lowestCommonAncestor(self, root: TreeNode, o1: int, o2: int) -> int:
        # write code here
        if not root:
            return -1

        elif root.val == o1 or root.val == o2:
            return root.val

        
        left = self.lowestCommonAncestor(root.left, o1, o2)
        right = self.lowestCommonAncestor(root.right, o1, o2)

        if left==-1:
            return right

        if right==-1:
            return left

        else:
            return root.val