1 class Solution { 2 public: 3     vector<vector<int> > permuteUnique(vector<int> &num)  4     { 5         vector<vector<int> > ans; 6         if (num.size() == 1) 7             {ans.push_back(num);return ans;} 8          9         vector<vector<int> > post;10         vector<int> tmp;11         vector<int> cur;12         sort(num.begin(), num.end()); // 排好序13         for (int i = 0; i < num.size(); ++i)14         {15             tmp = num;16             if (i - 1 >= 0 && tmp[i] == tmp[i - 1]) continue; //如果重复数字就跳过17             tmp.erase(tmp.begin() + i);18             post = permuteUnique(tmp);19             for (int j = 0; j < post.size(); ++j)20             {21                 cur = post[j];22                 cur.insert(cur.begin(), num[i]);23                 ans.push_back(cur);24             }25         }26         return ans;   27     }28 };