vector<vector<int> > subsetsWithDup(vector<int>& nums) {

vector<vector<int> > ret;

vector<int> sub;

sort(nums.begin(), nums.end());

backtack(nums, sub, ret, 0);

return ret;

}

void backtack(vector<int> &nums, vector<int> &sub, vector<vector<int> > &ret, int index)

{

if (find(ret.begin(), ret.end(), sub) == ret.end())

{

ret.push_back(sub);

}

for (int i = index; i < nums.size(); i ++)

{

sub.push_back(nums[i]);

backtack(nums, sub, ret, i + 1);

sub.pop_back();

}

}

{

int arr[3] = {1, 2, 2};

vector<int> nums(arr + 0, arr + 3);

Solution s;

vector<vector<int> > ret = s.subsetsWithDup(nums);

for (int i = 0; i < ret.size(); i ++)

{

cout << "i=" << i<< endl;

for (int j = 0; j < ret[i].size(); j ++)

{

cout << ret[i][j] << endl;

}

cout << "end" << endl;

}