leetcode

0 class Solution {

1 public:

2 vector<int> findDuplicates(vector<int> &nums) {

3 vector<int> res;

4 for (int i = 0; i < nums.size(); i++) {

5 int idx = abs(nums[i]) - 1;

6 if (nums[idx] < 0)

7 res.push_back(idx + 1);

8 else

9 nums[idx] = -nums[idx];

10 }

11

12 return res;

13 }

14 };