Binary Tree Paths
Difficulty: Easy
Category: DSA
Topics: String, Backtracking, Tree, Depth-First Search, Binary Tree
Asked at: Facebook, Google, Apple, Bloomberg
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:**
**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`