Given a binary tree and a sum, find all root-to-leaf paths where each path‘s sum equals the given sum.

              5
             /             4   8
           /   /           11  13  4
         /  \    /         7    2  5   1

return

[
   [5,4,11,2],
   [5,8,4,5]
]

class Solution {
public:
    vector<vector<int> > sumpath;
    void getPath(TreeNode *root, int cursum, int sum, vector<int> &path) {
        if(root == NULL) return;
        path.push_back(root->val);
        cursum += root->val;
        if(cursum == sum && root->left == NULL && root->right == NULL) sumpath.push_back(path);
        getPath(root->left, cursum, sum, path);
        getPath(root->right, cursum, sum, path);
        cursum -= root->val;
        path.pop_back();
    }
    vector<vector<int> > pathSum(TreeNode *root, int sum) {
        vector<int> path;
        getPath(root, 0, sum, path);
        return sumpath;
    }
};

Path Sum II