public class SuperFather {

    public static void main(String[] args) {
        int[] nums = {1, 2, 2, 3, 4, 6, 7, 5};
        int target = 6;
        Arrays.sort(nums);
        System.out.println(sum(target, nums, 0));
    }

    private static Set<List<Integer>> sum(int target, int[] nums, int index) {
        Set<List<Integer>> result = new HashSet<>();
        int currentNum = nums[index];

        if (currentNum == target) {
            List<Integer> lastList = new LinkedList<>();
            lastList.add(currentNum);
            result.add(lastList);
        } else if (currentNum < target && index < nums.length - 1) {
            result.addAll(sum(target, nums, index + 1));

            Set<List<Integer>> leftList = sum(target - currentNum, nums, index + 1);
            leftList.forEach(p -> p.add(currentNum));
            result.addAll(leftList);
        }

        return result;
    }
}