366. Find Leaves of Binary Tree

Given a binary tree, collect a tree's nodes as if you were doing this: Collect and remove all leaves, repeat until the tree is empty.

Example:

Input: [1,2,3,4,5]
 
          1
         / \
        2   3
       / \
      4   5

Output: [[4,5,3],[2],[1]]

Explanation:

1. Removing the leaves [4,5,3] would result in this tree:

          1
         /
        2

2. Now removing the leaf [2] would result in this tree:

          1

3. Now removing the leaf [1] would result in the empty tree:

          []