Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target.
Note:
- Given target value is a floating point.
- You are guaranteed to have only one unique value in the BST that is closest to the target.
Example:
Input: root = [4,2,5,1,3], target = 3.714286
4
/ \
2 5
/ \
1 3
Output: 4
题目
给定一棵二叉搜索树和一个target，求出其节点中最接近该target的值。
思路
1. based on the BST's attribution ( left < root < right), we use binary search
代码
1 class Solution { 2 public int closestValue(TreeNode root, double target) { 3 int result = root.val; 4 while(root != null){ 5 //update result if the current value is closer to target 6 if(Math.abs(target - root.val) < Math.abs(target - result)){ 7 result = root.val; 8 } 9 //binary search 10 root = root.val > target? root.left: root.right; 11 } 12 return result; 13 } 14 }