代码
class Solution {
public:
vector<vector<int>> subsets(vector<int>& nums) {
vector<vector<int>> ans;
int n = nums.size();
for (int i = 0; i < 1 << n; ++i) {
vector<int> path;
for (int j = 0; j < n; ++j) {
if (i >> j & 1) path.push_back(nums[j]);
}
ans.push_back(path);
}
return ans;
}
};