import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

public class subsets {

public static void main(String[] args) {

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

System.out.println(susbsetDuplicate(arr));

}

private static List<List<Integer>> susbsetDuplicate(int[] arr) {

Arrays.sort(arr);

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

outer.add(new ArrayList<>());

int start = 0,end = 0;

for (int i = 0; i < arr.length; i++) {

start = 0;

if(i>0 && arr[i] == arr[i-1])

start = end + 1;

end = outer.size() -1;

int n = outer.size();

for (int j = start; j < n; j++) {

List<Integer> internal = new ArrayList<>(outer.get(j));

internal.add(arr[i]);

outer.add(internal);

}

}

return outer;

}

}