题目

类型：回溯

解题思路

https://leetcode-cn.com/problems/subsets/solution/c-zong-jie-liao-hui-su-wen-ti-lei-xing-dai-ni-gao-/

代码

class Solution {
    public List<List<Integer>> subsets(int[] nums) {
        List<List<Integer>> res = new ArrayList<>();
        backtrack(0, nums, res, new ArrayList<Integer>());
        return res;
    }
    private void backtrack(int i, int[] nums, List<List<Integer>> res, ArrayList<Integer> tmp) {
        res.add(new ArrayList<>(tmp));
        for (int j = i; j < nums.length; j++) {
            tmp.add(nums[j]);
            backtrack(j + 1, nums, res, tmp);
            tmp.remove(tmp.size() - 1);
        }
    }
}