题目描述
给定一棵二叉搜索树,请找出其中的第k小的结点。例如, (5,3,7,2,4,6,8) 中,按结点数值大小顺序第三小结点的值为4。
说明:本题目包含复杂数据结构TreeNode,点此查看相关信息
# -*- coding:utf-8 -*-
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
# 返回对应节点TreeNode
def KthNode(self, pRoot, k):
# write code here
if not pRoot:
return None
ret = []
def inOrder(root):
if not root:
return None
inOrder(root.left)
ret.append(root)
inOrder(root.right)
return ret
result = inOrder(pRoot)
if 0<k<=len(result):
return result[k-1]
else:
return None