internal static BSTNodeBase <T> FindMax <T>(this BSTNodeBase <T> node) where T : IComparable
{
if (node == null)
{
return(null);
}
while (true)
{
if (node.Right == null)
{
return(node);
}
node = node.Right;
}
}
internal static void UpdateCounts <T>(this BSTNodeBase <T> node, bool spiralUp = false) where T : IComparable
{
while (node != null)
{
var leftCount = node.Left?.Count ?? 0;
var rightCount = node.Right?.Count ?? 0;
node.Count = leftCount + rightCount + 1;
node = node.Parent;
if (!spiralUp)
{
break;
}
}
}
internal static BSTNodeBase <T> NextHigher <T>(this BSTNodeBase <T> node) where T : IComparable
{
if (node.Parent == null || node.IsLeftChild)
{
if (node.Right != null)
{
node = node.Right;
while (node.Left != null)
{
node = node.Left;
}
return(node);
}
return(node.Parent);
}
if (node.Right != null)
{
node = node.Right;
while (node.Left != null)
{
node = node.Left;
}
return(node);
}
while (node.Parent != null && node.IsRightChild)
{
node = node.Parent;
}
return(node?.Parent);
}
public bool MoveNext()
{
if (root == null)
{
return(false);
}
if (current == null)
{
current = asc ? root.FindMin() : root.FindMax();
return(true);
}
var next = asc ? current.NextHigher() : current.NextLower();
if (next != null)
{
current = next;
return(true);
}
return(false);
}
internal static int Position <T>(this BSTNodeBase <T> node, T item) where T : IComparable
{
if (node == null)
{
return(-1);
}
var leftCount = node.Left?.Count ?? 0;
if (node.Value.CompareTo(item) == 0)
{
return(leftCount);
}
if (item.CompareTo(node.Value) < 0)
{
return(Position(node.Left, item));
}
var position = Position(node.Right, item);
return(position < 0 ? position : position + leftCount + 1);
}
public void Dispose()
{
current = null;
}
public void Reset()
{
current = root;
}
internal BSTEnumerator(BSTNodeBase <T> root, bool asc = true)
{
this.root = root;
this.asc = asc;
}
