1 class Solution {
 2 public:
 3     void reOrderArray(vector<int> &arr) {
 4         vector<int> odd;
 5         vector<int> even;
 6         for (auto &i: arr) {
 7             if (i & 1) {
 8                 odd.push_back(i);
 9             } else {
10                 even.push_back(i);
11             }
12         }
13         int i = 0;
14         while (i < odd.size()) {
15             arr[i] = odd[i];
16             i++;
17         }
18         while (i < arr.size()) {
19             arr[i] = even[i - odd.size()];
20             i++;
21         }
22     }
23 };