// Source : https://oj.leetcode.com/problems/path-sum-ii/
// Author : Hao Chen
// Date : 2014-07-01
/**********************************************************************************
*
* 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]
* ]
*
*
**********************************************************************************/
/**
* 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