90. 子集 II

 1 //套模板
 2 class Solution 
 3 {
 4     vector<vector<int>> res;
 5     void helper(vector<int>& nums, int start, vector<int>& out)
 6     {
 7         res.push_back(out);
 8         for (int i = start; i < nums.size(); ++i)
 9         {
10             out.push_back(nums[i]);
11             helper(nums, i + 1, out);
12             out.pop_back();
13         }
14     }
15 public:
16     vector<vector<int>> subsetsWithDup(vector<int>& nums) 
17     {
18         vector<int> out;
19         sort(nums.begin(),nums.end());//排序
20         helper(nums,0,out);
21         //去重
22         sort(res.begin(),res.end());
23         auto it = unique(res.begin(),res.end());
24         res.erase(it,res.end());
25 
26         return res;
27     }
28 };