# 0938. Range Sum of BST

https://leetcode.com/problems/range-sum-of-bst

## Description

Given the `root` node of a binary search tree and two integers `low` and `high`, return _the sum of values of all nodes with a value in the **inclusive** range_ `[low, high]`.

**Example 1:**

![](https://assets.leetcode.com/uploads/2020/11/05/bst1.jpg)

```
**Input:** root = [10,5,15,3,7,null,18], low = 7, high = 15
**Output:** 32
**Explanation:** Nodes 7, 10, and 15 are in the range [7, 15]. 7 + 10 + 15 = 32.
```

**Example 2:**

![](https://assets.leetcode.com/uploads/2020/11/05/bst2.jpg)

```
**Input:** root = [10,5,15,3,7,13,18,1,null,6], low = 6, high = 10
**Output:** 23
**Explanation:** Nodes 6, 7, and 10 are in the range [6, 10]. 6 + 7 + 10 = 23.
```

**Constraints:**

* The number of nodes in the tree is in the range `[1, 2 * 104]`.
* `1 <= Node.val <= 105`
* `1 <= low <= high <= 105`
* All `Node.val` are **unique**.

## ac

```java
```
