Subsets II

class Solution {
    Set<List<Integer>> rep = new HashSet<>();
    List<List<Integer>> res = new ArrayList<>();
    public List<List<Integer>> subsetsWithDup(int[] nums) {
        add(nums, new ArrayList<>(), 0);
        return res;
    }
    public void add(int[] nums, List<Integer> store, int index){
        if(index == nums.length){
            List<Integer> temp = new ArrayList<>(store);
            Collections.sort(temp);
            if(rep.add(new ArrayList<>(temp))) res.add(new ArrayList<>(store));
            return ;
        }
        store.add(nums[index]);
        add(nums, store, index+1);
        store.remove(store.size()-1);
        add(nums, store, index+1);
    }    
}