码迷,mamicode.com
首页 > 其他好文 > 详细

[Leetcode] Binary tree--653. Two Sum IV - Input is a BST

时间:2017-08-26 12:38:35      阅读:148      评论:0      收藏:0      [点我收藏+]

标签:etc   get   bin   tput   ret   store   binary   put   target   

Given a Binary Search Tree and a target number, return true if there exist two elements in the BST such that their sum is equal to the given target.

Example 1:

Input: 
    5
   /   3   6
 / \   2   4   7

Target = 9

Output: True

 

Example 2:

Input: 
    5
   /   3   6
 / \   2   4   7

Target = 28

Output: False

 Solution:

 

        #traverse the tree and using‘s hash to store visited node
        dic = {}
        def helperRecursive(root):
            if root is None:
                return False
            if (k - root.val) in dic:
                return True
            if root.val not in dic:
                dic[root.val] = 1
            return helperRecursive(root.left) or helperRecursive(root.right)

        return helperRecursive(root)

  

 

 

[Leetcode] Binary tree--653. Two Sum IV - Input is a BST

标签:etc   get   bin   tput   ret   store   binary   put   target   

原文地址:http://www.cnblogs.com/anxin6699/p/7434863.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!