/// <summary>
/// Initializes a new instance of the <see cref="FibonacciHeap{TPriority,TValue}"/> class.
/// </summary>
/// <param name="direction">Heap direction.</param>
/// <param name="priorityComparison">Priority comparer.</param>
/// <exception cref="T:System.ArgumentNullException"><paramref name="priorityComparison"/> is <see langword="null"/>.</exception>
public FibonacciHeap(HeapDirection direction, [NotNull] Comparison <TPriority> priorityComparison)
{
_cells = new FibonacciHeapLinkedList <TPriority, TValue>();
_degreeToCell = new Dictionary <int, FibonacciHeapCell <TPriority, TValue> >();
_directionMultiplier = (short)(direction == HeapDirection.Increasing ? 1 : -1);
Direction = direction;
PriorityComparison = priorityComparison ?? throw new ArgumentNullException(nameof(priorityComparison));
Count = 0;
}
/// <summary>
/// Merges the given <paramref name="cells"/> at the end of this cells list.
/// </summary>
/// <param name="cells">Cells to merge.</param>
internal void MergeLists([NotNull] FibonacciHeapLinkedList <TPriority, TValue> cells)
{
Debug.Assert(cells != null);
if (cells.First is null)
{
return;
}
if (_last != null)
{
_last.Next = cells.First;
}
cells.First.Previous = _last;
_last = cells._last;
if (First is null)
{
First = cells.First;
}
}