# 0257. Binary Tree Paths

<https://leetcode.com/problems/binary-tree-paths>

## Description

Given the `root` of a binary tree, return *all root-to-leaf paths in **any order***.

A **leaf** is a node with no children.

**Example 1:**

![](https://assets.leetcode.com/uploads/2021/03/12/paths-tree.jpg)

```
**Input:** root = [1,2,3,null,5]
**Output:** ["1->2->5","1->3"]
```

**Example 2:**

```
**Input:** root = [1]
**Output:** ["1"]
```

**Constraints:**

* The number of nodes in the tree is in the range `[1, 100]`.
* `-100 <= Node.val <= 100`

## ac

```java
```