题目：

题解：

class Solution {
public:vector<int> t;vector<vector<int>> ans;void dfs(int cur, vector<int>& nums) {if (cur == nums.size()) {ans.push_back(t);return;}t.push_back(nums[cur]);dfs(cur + 1, nums);t.pop_back();dfs(cur + 1, nums);}vector<vector<int>> subsets(vector<int>& nums) {dfs(0, nums);return ans;}
};