KeyValuePair <TKey, TValue>?ISortedDictionary <TKey, TValue> .Higher(TKey key)
{
RBTree.Node highParent = null;
RBTree.Node current = tree.root;
while (current != null)
{
int cmp = hlp.Compare(key, current);
if (cmp < 0)
{
highParent = current;
current = current.left;
}
else if (cmp > 0)
{
current = current.right;
}
else
{
break;
}
}
// we finished walk on a node with key equal to ours
if (current != null && current.right != null)
{
return(((Node)current.right.FirstNode()).AsKV());
}
if (highParent == null)
{
return(null);
}
else
{
return(((Node)highParent).AsKV());
}
}