class Solution(object):
def lowestCommonAncestor(self
, root
, p
, q
):
"""
:type root: TreeNode
:type p: TreeNode
:type q: TreeNode
:rtype: TreeNode
"""
if not root
:
return None
aim
=root
pp
=p
.val
qq
=q
.val
if pp
<qq
:
while aim
.val
!=pp
and aim
.val
!=qq
:
a
=aim
.val
if a
>qq
:
aim
=aim
.left
if a
<pp
:
aim
=aim
.right
if a
>pp
and a
<qq
:
return aim
else:
while aim
.val
!=pp
and aim
.val
!=qq
:
a
=aim
.val
if a
>pp
:
aim
=aim
.left
if a
<qq
:
aim
=aim
.right
if a
>qq
and a
<pp
:
return aim
return aim
二叉搜索树的定义一定要搞明白，明白了以后就是比大小
