Find largest and second largest element in a range

Question

How do I find the above without removing the largest element and searching again? Is there a more efficient way to do this? It does not matter if the these elements are dupl

Answer 1

You can scan the list in one pass and save the 1st and 2nd values, that has a O(n) efficiency while sorting is O(n log n).

EDIT:
I think that partial sort is O(n log k)