public RedBlackLeaf(TKey key, TValue value, RedBlackLeaf <TKey, TValue> parent)
{
Parent = parent;
Key = key;
Value = value;
Color = LeafColor.RED;
Comparer = new Comparer(CultureInfo.InvariantCulture);
}
public override IRedBlackLeaf <TKey, TValue> Insert(IRedBlackLeaf <TKey, TValue> root,
IRedBlackLeaf <TKey, TValue> leaf)
{
if (Root.IsEmpty())
{
Root = leaf;
}
else
{
IRedBlackLeaf <TKey, TValue> g, t, p, q, head;
head = new RedBlackLeaf <TKey, TValue>(default(TKey), default(TValue), null);
g = t = q = p = null;
bool direction, last;
direction = last = false;
t = head;
q = t.Right = Root;
for ( ;;)
{
if (q.IsEmpty())
{
p[direction] = q = leaf;
if (q.IsEmpty())
{
return(Root);
}
}
else if (q.Left.IsRed() && q.Right.IsRed())
{
q.Color = LeafColor.RED;
q.Left.Color = LeafColor.BLACK;
q.Right.Color = LeafColor.BLACK;
}
if (q.IsRed() && p.IsRed())
{
var newDirection = t.Right.Key.Equals(g.Key);
var lastIteration = p[last];
var lastIterationKey = lastIteration == null ? default(TKey) : lastIteration.Key;
if (q.Key.Equals(lastIterationKey))
{
t[newDirection] = Rotate(g, !last);
}
else
{
t[newDirection] = DoubleRotate(g, !last);
}
}
if (q.Key.Equals(leaf.Key))
{
break;
}
last = direction;
direction = q.LessThan(leaf);
if (!g.IsEmpty())
{
t = g;
}
g = p;
p = q;
q = q[direction];
}
Root = head.Right;
}
Root.Color = LeafColor.BLACK;
return(Root);
}