题解 | #二叉搜索树的最近公共祖先#

# 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 p int整型 
# @param q int整型 
# @return int整型
#
class Solution:
    def lowestCommonAncestor(self , root: TreeNode, p: int, q: int) -> int:
        # write code here
        if not root:
            return -1
        p,q = min(p,q),max(p,q)
        if root.val>= p and root.val <= q:
            return root.val
        if root.val > q:
            return self.lowestCommonAncestor(root.left,p,q)
        if root.val < p:
            return self.lowestCommonAncestor(root.right,p,q)
        return -1