/// <inheritdoc />
public bool TryPop(out HeapPair <T, TPriority> value)
{
value = default;
if (IsEmpty)
{
return(false);
}
// Swap then remove.
var root = _binaryHeap[0];
Swap(0, Count - 1);
_binaryHeap.RemoveAt(Count - 1);
// Assign item and remove it from mapping.
value = HeapPair.Create(root.Value, root.Priority);
_lookup.Remove(root.Value);
HeapNodePool.Return(root);
// If there aren't any elements left, no sifting is needed.
if (1 < Count)
{
SiftDown(0);
}
return(true);
}
/// <inheritdoc />
public bool TryPeek(out HeapPair <T, TPriority> value)
{
value = default;
if (!_binaryHeap.Any())
{
return(false);
}
var element = _binaryHeap[0];
value = HeapPair.Create(element.Value, element.Priority);
return(true);
}
/// <inheritdoc />
public bool TryReplace(T newValue, TPriority priority, out HeapPair <T, TPriority> oldValue)
{
oldValue = default;
if (IsEmpty)
{
return(false);
}
var node = _binaryHeap[0];
oldValue = HeapPair.Create(node.Value, node.Priority);
_lookup.Remove(node.Value);
_lookup.Add(newValue, node);
node.Value = newValue;
node.Priority = priority;
SiftDown(node.Index);
return(true);
}
/// <inheritdoc /> IEnumerator <HeapPair <T, TPriority> > IEnumerable <HeapPair <T, TPriority> > .GetEnumerator() => _binaryHeap.Select(n => HeapPair.Create(n.Value, n.Priority)).GetEnumerator();