二叉树中和为某一值的路径

{
      vector<vector<int>> pathSum(TreeNode* root, int sum) {
        vector<vector<int>> paths;
        vector<int> path;
        DFS (root, sum, path, paths);
        return paths;
        
        
    }
    void  (TreeNode* root, int sum, vector<int>& path, vector<vector<int>>& paths) {
        if (root == nullptr) {
            return ;
        }
        path.push_back(root->val);
        if (root->left == nullptr && root->right == nullptr && root->val == sum) {
            paths.push_back(path);
        }
        DFS (root->left, sum - root->val, path, paths);
        DFS (root->right, sum - root->val, path, paths);
        path.pop_back();
    }
}