Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target.
Note:
Example:
Input: root = [4,2,5,1,3], target = 3.714286
4
/ 2 5
/ 1 3
Output: 4
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public int closestValue(TreeNode root, double target) { if (root == null) { return -1; } int res = root.val; while (root != null) { if (Math.abs(root.val - target) < Math.abs(res - target)) { res = root.val; } if (root.val > target) { root = root.left; } else { root = root.right; } } return res; } }
[LC] 270. Closest Binary Search Tree Value
原文：https://www.cnblogs.com/xuanlu/p/12242321.html