#### Approach #1 Sort and verify neighbors [Accepted]

**Intuition**

Sort the given array elements and check every element with it's adjacent element

to verify whether they are same or not. If yes add them to duplicates.

**Algorithm**

Suppose we have a function `findDuplicates`

....

**C++**

```
vector<int> findDuplicates(vector<int>& nums) {
std :: sort(nums.begin(),nums.end());
vector<int> Duplicates;
int length = nums.size();
for(int i=0;i<=length-1;i++)
{
if(nums[i]==nums[i+1])
{
Duplicates.push_back(nums[i]);
}
}
return Duplicates;
}
```

**Complexity Analysis**

- Time complexity : $$O(nlogn)$$.

std::sort have average case (n log n) time complexity