Leetcode 90. Subsets II

Given a collection of integers that might contain duplicates, nums, return all possible subsets.

Note: The solution set must not contain duplicate subsets.

For example,
If nums = [1,2,2], a solution is:

[
  [2],
  [1],
  [1,2,2],
  [2,2],
  [1,2],
  []
]

class Solution {
public:
    vector<vector<int>> subsetsWithDup(vector<int>& nums) {
        sort(nums.begin(),nums.end());
        //无重复
        int tag = 0;
        int record = 0;
        vector<vector<int>> result;
        vector<int> line;
        result.push_back(line);
        line.push_back(nums[0]);
        result.push_back(line);
        for(int i = 1;i<nums.size();i++){
            if(nums[i]!=nums[i-1]){
                int n = result.size();
                for(int j = 0; j<n ; j++){
                     vector<int> temp = result[j];
                     temp.push_back(nums[i]);
                     result.push_back(temp);
                     tag = 0;
                }
                record = n;
            }
            if(nums[i]==nums[i-1]){
                int n = result.size();
                if(tag == 0){//上一个没有重复
                    for(int j = n/2;j<n;j++){
                     vector<int> temp = result[j];
                     temp.push_back(nums[i]);
                     result.push_back(temp);
                     tag = 1;
                    }
                    record = n/2;
                }
                else if(tag == 1){
                    for(int j = n-record;j<n;j++){
                        vector<int> temp = result[j];
                        temp.push_back(nums[i]);
                        result.push_back(temp);
                        tag = 1;
                    }
                    record = record;
                }
                
            }
        }
        return result;
    }
};