Find duplicates in the given array

find_duplicates.h

#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

template <typename T>
vector<T> *findDuplicates(T *elements, unsigned int length) {
    sort(elements, elements + length);

    vector<T> *duplicates = new vector<T>();

    for(unsigned int i = 1; i < length; i++) {
        if(elements[i] == elements[i-1] && find(duplicates->begin(), duplicates->end(), elements[i]) == duplicates->end()) {
            duplicates->push_back(elements[i]);
        }
    }

    return duplicates;
}