题目描述
输入一棵二叉树，求该树的深度。从根结点到叶结点依次经过的结点（含根、叶结点）形成树的一条路径，最长路径的长度为树的深度。
class TreeNode:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
class Solution:
def TreeDepth(self, pRoot):
# write code here
if not pRoot: return 0
queue = [pRoot]
deep = 0
while queue:
n = len(queue)
for _ in range(n):
node = queue.pop(0)
if node.left: queue.append(node.left)
if node.right: queue.append(node.right)
deep += 1
return deep