Problem 270: Closest Binary Search Tree Value
https://leetcode.com/problems/closest-binary-search-tree-value/#/description

思路
这道题在 Google 面试的时候遇到了,当时竟然懵逼了。主要是当时没有注意是 Binary Search Tree,也就是隐含了一个信息是:
所有的元素是从左到右排列好的。
用个一个元素标记最接近的值,然后遇到更接近的就更新。
root 走的方向通过最接近的路径走。
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public int closestValue(TreeNode root, double target) {
int closest = root.val;
while (root != null) {
if (Math.abs(root.val - target) < Math.abs(closest - target)) closest = root.val;
root = (root.val > target ? root.left : root.right);
}
return closest;
}
}
Last updated
Was this helpful?