public object Dequeue()
{
heapSize = heapSize - 1;
object max = heap [0].obj;
PriorityObject newElement = heap [heapSize];
FixHeap(newElement, 0);
return(max);
}
private void AppendToArray(PriorityObject el)
{
int cap = heap.GetLength(0);
if (heapSize + 1 >= cap)
{
PriorityObject[] newHeap = new PriorityObject[cap * 2];
for (int i = 0; i < heapSize; i++)
{
newHeap [i] = heap [i];
}
heap = newHeap;
}
heap [heapSize] = el;
heapSize = heapSize + 1;
}
public void Enqueue(object el, float priority)
{
PriorityObject obj = new PriorityObject(el, priority);
AppendToArray(obj);
// Percolate-up
int currentIndex = heapSize - 1;
int parentIndex = (currentIndex - 1) / 2;
while (parentIndex >= 0 && heap [parentIndex] < heap [currentIndex])
{
var temp = heap [parentIndex];
heap [parentIndex] = heap [currentIndex];
heap [currentIndex] = temp;
currentIndex = parentIndex;
parentIndex = (currentIndex - 1) / 2;
}
}
private void FixHeap(PriorityObject obj, int index)
{
PriorityObject maxChild;
int maxIndex;
if (index * 2 + 1 < heapSize)
{
maxChild = heap [index * 2 + 1];
maxIndex = index * 2 + 1;
if (index * 2 + 2 < heapSize)
{
var child = heap [index * 2 + 2];
if (child > maxChild)
{
maxChild = child;
maxIndex = index * 2 + 2;
}
}
if (maxChild > obj)
{
heap [index] = maxChild;
FixHeap(obj, maxIndex);
}
else
{
heap [index] = obj;
}
}
else
{
// else stop! no children to check; we're a leaf now
heap [index] = obj;
}
}
