257\. Binary Tree Paths

Easy

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`