All Subtrees With a Given Sum

  private static List<List<Tree<Integer>>> getTreesWithSum(Tree<Integer> current,
                                                             int currentSum, int targetSum,
                                                             List<List<Tree<Integer>>> result) {
        currentSum += current.value;

        for (Tree<Integer> child : current.children) {
            currentSum += child.value;

            getTreesWithSum(child, 0, targetSum, result);
        }

        if (currentSum == targetSum) {
            List<Tree<Integer>> subtree = new ArrayList<>();

            subtree.add(current);

            subtree.addAll(current.children);

            result.add(subtree);
        }

        return result;
    }