# Problem Definition

## Description

Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target.

**Note:**

* Given target value is a floating point.
* You may assume k is always valid, that is: k ≤ total nodes.
* You are guaranteed to have only one unique set of k values in the BST that are closest to the target.

**Example:**

```plaintext
Input: root = [4,2,5,1,3], target = 3.714286, and k = 2

    4
   / \
  2   5
 / \
1   3

Output: [4,3]
```

**Follow up :**
Assume that the BST is balanced, could you solve it in less than O(n) runtime (where n = total nodes)?

## Notes