How to get Priority of C# PriorityQueue element

Question

I am initializing a priority queue that stores XY coordinates, prioritized by their euclidian distance from origin. I created a custom Comparer that makes this operate as a max heap:

PriorityQueue<int[], double> maxHeap = new PriorityQueue<int[], double>(Comparer<double>.Create((x, y) => x.CompareTo(y)));

This works great, except sometimes I want to be able to look at the top of the heap using Peek(). I can get the value of the element, the point which has type int[], but I can't get the priority. I don't see anything that would allow me to access TPriority. Take this use case for example, which is a common usage of heaps to get the top/bottom K elements in a collection:

for (int i = k; i < points.Length; i++)
{
    double euclidianDistance = EuclidianDistance(points[i]);
    if (euclidianDistance < EuclidianDistance(maxHeap.Peek()))
    {
        maxHeap.Dequeue();
        maxHeap.Enqueue(points[i], euclidianDistance);
    }
}

You will see that I have to compute the euclidian distance again for the element at the top of the heap. Visual Studio shows me this, although I cannot seem to access that second property of type double which refers to the priority.

Answer 1

I figured out that this requires usage of a try/get:

for (int i = k; i < points.Length; i++)
{
    double euclidianDistance = EuclidianDistance(points[i]);
    if (maxHeap.TryPeek(out int[] topPoint, out double priority) && euclidianDistance < priority)
    {
        maxHeap.Dequeue();
        maxHeap.Enqueue(points[i], euclidianDistance);
    }
}