package leetcode;

import java.util.*;

/**

* @author : zhaochengming

* @date : 2022/5/16 0:20

* @description : https://leetcode.cn/problems/subsets/

*/

public class L0078_Subsets {

static class Solution {

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

private void backTrack(int[] nums, int start, Deque<Integer> track) {

res.add(new LinkedList<>(track));

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

track.addLast(nums[i]);

backTrack(nums, i + 1, track);

track.pollLast();

}

}

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

Deque<Integer> track = new LinkedList<>();

backTrack(nums, 0, track);

return res;

}

}

}