LeetCode – Refresh – Permutations II

 1 class Solution {
 2 public:
 3     void getP(vector<vector<int> > &result, vector<int> &num, vector<int> current, vector<bool> rec) {
 4         if (num.size() == current.size()) {
 5             result.push_back(current);
 6             return;
 7         }
 8         for (int i = 0; i < num.size(); i++) {
 9             if (rec[i] || (i > 0 && num[i] == num[i-1] && rec[i-1])) continue;
10             rec[i] = true;
11             current.push_back(num[i]);
12             getP(result, num, current, rec);
13             rec[i] = false;
14             current.pop_back();
15         }
16     }
17     vector<vector<int> > permuteUnique(vector<int> &num) {
18         vector<vector<int> > result;
19         sort(num.begin(), num.end());
20         getP(result, num, vector<int> (), vector<bool> (num.size(), false));
21         return result;
22     }
23 };