90. Subsets II

 public List<List<Integer>> subsetsWithDup(int[] nums) {
        List<List<Integer>> list = new ArrayList<>();
        list.add(new ArrayList<>());
        for(int i = 1; i <= nums.length; i++) {
            Set<List<Integer>> tlist = recurSub(nums, 0, i);
            for(List<Integer> tmp: tlist) {
                list.add(tmp);
            }
        }
        return list;    
    }

    public Set<List<Integer>> recurSub(int[] nums, int start,int len) {
        Set<List<Integer>> list = new HashSet<>();
        for(int i = start; i < nums.length; i++) {
            if(len > 1) {
                for(List<Integer> tList : recurSub(nums, i+1, len-1)) {
                    tList.add(nums[i]);
                    Collections.sort(tList);
                    list.add(tList);
                }
            }else if(len == 1) {
                 list.add(new LinkedList<Integer>(Arrays.asList(nums[i])));
            }
        }
        return list;
    }