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