Given the root of a binary tree and an integer targetSum, return all root-to-leaf paths where the sum of the node values in the path equals targetSum.
Example 1:
Input: root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22 Output: [[5,4,11,2],[5,8,4,5]]
Example 2:
Input: root = [1,2,3], targetSum = 5 Output: []
Constraints:
[0, 5000].-1000 <= Node.val <= 1000-1000 <= targetSum <= 1000