// Source : https://leetcode.com/problems/path-sum-ii/
// Author : Yijing Bai
// Date   : 2015-12-22

/********************************************************************************** 
 * 
 * Given a binary tree and a sum, find all root-to-leaf paths where each path's sum 
 * equals the given sum.
 * 
 * For example:
 * Given the below binary tree and sum = 22,
 * 
 *               5
 *              / \
 *             4   8
 *            /   / \
 *           11  13  4
 *          /  \    / \
 *         7    2  5   1
 * 
 * return
 * 
 * [
 *    [5,4,11,2],
 *    [5,8,4,5]
 * ]
 * 
 *               
 *               
 * 
 *               
 *               
 * 
 *               
 **********************************************************************************/



