/**
* Internal method to handle duplicates into a subtree.
*
* @param x the item to insert.
* @param t the node that roots the tree.
* @return the new root.
* @throws DuplicateItemException if x is already present.
*/
protected BinaryNode<AnyType> duplicate(AnyType x, BinaryNode<AnyType> t) {
if (t == null) {
t = new BinaryNode<AnyType>(x);
} else {
t.duplicate = duplicate(x, t.duplicate);
}
return t;
}
/**
* Internal method to insert into a subtree.
*
* @param x the item to insert.
* @param t the node that roots the tree.
* @return the new root.
* @throws DuplicateItemException if x is already present.
*/
protected BinaryNode<AnyType> insert(AnyType x, BinaryNode<AnyType> t) {
if (t == null) t = new BinaryNode<AnyType>(x);
else if (x.compareTo(t.element) < 0) t.left = insert(x, t.left);
else if (x.compareTo(t.element) > 0) t.right = insert(x, t.right);
else {
t.increaseDuplicateCount();
t.hasDuplicate = true;
t.duplicate = duplicate(x, t.duplicate);
}
return t;
}