Programming challenge: find top values in unsorted array

Recently, I was given a programming problem for a pre-interview job screen.

Implementation

• Create a class which implements either the C# or Java interface
• Implement the two methods defined in the interface. FindMaxValue should return the single highest integer. FindTopNValues should return a list of the highest 'n' values in the source list
• Any assumptions or design choices made during the implementation should be documented.

C# interface

namespace Test
{
   public interface IFindTopValues
   {
      int FindMaxValue(int[] values);
      int[] FindTopNValue(int[] values, int count);
   }

Test cases

• Describe the test cases which you would implement for this class.

Here's the solution I produced. It uses a C# generic PriorityQueue class. Have a look -- it's useful, reusable code.

Update (2008-05-15): I noticed that Julian Bucknall had a change to his priority queue that ordered entries by priority and time of entry. I decided to update my code to provide the same ability.