package leetcode;
import java.util.*;
public class Subsets {
	public List<List<Integer>> subsets(int[] nums) {
	    List<List<Integer>> list = new ArrayList<>();
	    Arrays.sort(nums);
	    backtrack(list, new ArrayList<>(), nums, 0);
	    return list;
	}

	private void backtrack(List<List<Integer>> list , List<Integer> tempList, int [] nums, int start){
	    list.add(new ArrayList<>(tempList));
	    for(int i = start; i < nums.length; i++){
	        tempList.add(nums[i]);
	        backtrack(list, tempList, nums, i + 1);
	        tempList.remove(tempList.size() - 1);
	    }
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
    	int nums[]= {1,2,3};
    	new Subsets().subsets(nums);
	}
}