# 1676. Lowest Common Ancestor of a Binary Tree IV

https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree-iv

## Description

Given the `root` of a binary tree and an array of `TreeNode` objects `nodes`, return _the lowest common ancestor (LCA) of **all the nodes** in_ `nodes`. All the nodes will exist in the tree, and all values of the tree's nodes are **unique**.

Extending the [**definition of LCA on Wikipedia**](https://en.wikipedia.org/wiki/Lowest_common_ancestor): "The lowest common ancestor of `n` nodes `p1`, `p2`, ..., `pn` in a binary tree `T` is the lowest node that has every `pi` as a **descendant** (where we allow **a node to be a descendant of itself**) for every valid `i`". A **descendant** of a node `x` is a node `y` that is on the path from node `x` to some leaf node.

**Example 1:**

![](https://assets.leetcode.com/uploads/2018/12/14/binarytree.png)

```
**Input:** root = [3,5,1,6,2,0,8,null,null,7,4], nodes = [4,7]
**Output:** 2
**Explanation:** The lowest common ancestor of nodes 4 and 7 is node 2.
```

**Example 2:**

![](https://assets.leetcode.com/uploads/2018/12/14/binarytree.png)

```
**Input:** root = [3,5,1,6,2,0,8,null,null,7,4], nodes = [1]
**Output:** 1
**Explanation:** The lowest common ancestor of a single node is the node itself.
```

**Example 3:**

![](https://assets.leetcode.com/uploads/2018/12/14/binarytree.png)

```
**Input:** root = [3,5,1,6,2,0,8,null,null,7,4], nodes = [7,6,2,4]
**Output:** 5
**Explanation:** The lowest common ancestor of the nodes 7, 6, 2, and 4 is node 5.
```

**Example 4:**

![](https://assets.leetcode.com/uploads/2018/12/14/binarytree.png)

```
**Input:** root = [3,5,1,6,2,0,8,null,null,7,4], nodes = [0,1,2,3,4,5,6,7,8]
**Output:** 3
**Explanation:** The lowest common ancestor of all the nodes is the root node.
```

**Constraints:**

* The number of nodes in the tree is in the range `[1, 104]`.
* `-109 <= Node.val <= 109`
* All `Node.val` are **unique**.
* All `nodes[i]` will exist in the tree.
* All `nodes[i]` are distinct.

## ac

```java
```
