package LeetCode;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;

public class Subsets {

private List<List<Integer>> res=new ArrayList<>();

public List<List<Integer>> subsets(int[] nums) {

helper(nums,new ArrayList<>(),0);

HashSet h=new HashSet(res);

res.clear();

res.addAll(h);

return res;

}

public void helper(int[]nums,List<Integer>list,int start){

res.add(new ArrayList<Integer>(list));

for (int i = start; i < nums.length; i++) {

// if (list.contains(nums[i])) {

// continue;

// }

list.add(nums[i]);

helper(nums, list,i+1);

list.remove(list.size() - 1);

}

}

public static void main(String[]args){

int nums[]={1,2,2};

Subsets s=new Subsets();

List<List<Integer>> result=new ArrayList<>();

result=s.subsets(nums);

System.out.println(result);

}

}