public class Solution
extends Object
1302 - Deepest Leaves Sum\.
Medium
Given the `root` of a binary tree, return _the sum of values of its deepest leaves_.
**Example 1:**
**Input:** root = [1,2,3,4,5,null,6,7,null,null,null,null,8]
**Output:** 15
**Example 2:**
**Input:** root = [6,7,8,2,7,1,3,9,null,1,4,null,null,null,5]
**Output:** 19
**Constraints:**
* The number of nodes in the tree is in the range [1, 104].
* `1 <= Node.val <= 100`