思路:采用二叉树的深度优先遍历,如果是叶子节点更新最大值和最小值。
# Definition for a binary tree node.
# class TreeNode(object):
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution(object):
def maxDepth(self, root):
"""
:type root: TreeNode
:rtype: int
"""
if not root: return 0
self.max=0
self._dfs(root,0)
return self.max+1
def _dfs(self,node,level):
if not node: return
if node.left==None and node.right==None:
if level>self.max:
self.max=level
return
self._dfs(node.left,level+1)
self._dfs(node.right,level+1)
return