public static long Sum(long leftKey, long rightKey, BinarySearchTreeNode root)
{
long results = 0;
var node = Find(leftKey, root);
while (node != null && node.Key <= rightKey)
{
if (node.Key >= leftKey)
{
results += node.Key;
}
node = BinarySearchTree.Next(node);
}
return(results);
}
private static BinarySearchTreeNode Delete(BinarySearchTreeNode node)
{
Splay(BinarySearchTree.Next(node));
Splay(node);
return(BinarySearchTree.Delete(node));
}