Path Sum II

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]
]

class Solution {
public:
	vector<vector<int> > res;
	void judge(TreeNode* root, vector<int> vec, int last, int sum)
	{
		if (0 == root) return;
		if (root->left == 0 && 0 == root->right)
		{
			if (last + root->val == sum)
			{
				vec.push_back(root->val);
				res.push_back(vec);
			}
		}
		else
		{
			vec.push_back(root->val);
			judge(root->left, vec, last + root->val, sum);
			judge(root->right, vec, last + root->val, sum);
		}
	}
    vector<vector<int> > pathSum(TreeNode *root, int sum) 
	{
		res.clear();
		vector<int> tmp;
		judge(root, tmp, 0, sum);
		return res;
    }
};