Finding the first n largest elements in an array

Question

I have got an array containing unique elements. I need to find out the first n largest elements in the array in the least complexity possible. The solution that I could thin

Answer 1

Find the kth biggest element, using selection algorithm.
Next, iterate the array and find all elements which are larger/equal it.

complexity: O(n) for selection and O(n) for iterating, so the total is also O(n)