/**

 * Definition for binary tree

 * struct TreeNode {

 *     int val;

 *     TreeNode *left;

 *     TreeNode *right;

 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}

 * };

 */

class Solution {

public:

        vector<vector<int> > levelOrderBottom(TreeNode *root) {

        vector<vector<int> > ans;

        if(root == NULL)

            return ans;

        int num = ,num2 = ,nullNum = ,nullNumAcc = ;

        queue<TreeNode *> myQueue;

        myQueue.push(root);

        TreeNode *nodeFront;

        vector<int> onePiece;

        while(!myQueue.empty())

        {

            nodeFront = myQueue.front();

            myQueue.pop();

            num--;

            onePiece.push_back(nodeFront->val);

            if(nodeFront->left)

                myQueue.push(nodeFront->left);

            else

                nullNum++;

            if(nodeFront->right)

                myQueue.push(nodeFront->right);

            else

                nullNum++;

            if(num == )

            {

                if(onePiece.empty())

                    break;

                ans.push_back(onePiece);

                onePiece.clear();

                num2 = num2*;

                nullNumAcc = nullNumAcc* + nullNum;

                num = num2 - nullNumAcc;

                nullNum = ;

            }

        }

        reverse(ans.begin(),ans.end());

        return ans;

    }

};