/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
public List> levelOrderBottom(TreeNode root) {
List
> result = new ArrayList
>();
if (root == null) return result;
Queue
> reversed_result = new ArrayList
>();
for (int i = result.size() - 1; i >= 0; i--) {
reversed_result.add(result.get(i));
}
return reversed_result;
}
}