Given the root of a binary tree, collect a tree's nodes as if you were doing this:

• Collect all the leaf nodes.
• Remove all the leaf nodes.
• Repeat until the tree is empty.

 

Example 1:

Input: root = [1,2,3,4,5]
Output: [[4,5,3],[2],[1]]
Explanation:
[[3,5,4],[2],[1]] and [[3,4,5],[2],[1]] are also considered correct answers since per each level it does not matter the order on which elements are returned.

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