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
# 思路：如果当前节点在pq之间，返回当前节点，如果大于pq，则去右节点，小于去左
        max_num = max(p,q)
        min_num = min(p,q)
        while root:
            tmp = root.val
            if tmp >= min_num and tmp <= max_num:
                return root.val
            if tmp > max_num:
                root = root.left
            else:
                root = root.right
        return 0