Write height-balanced tree code with backpointers, based on the height-balanced tree code.
You should modify the code in such a way that there are no stacks used anymore for following the path upward during rebalancing; instead each non-root node should have an additional field up that points to the upper neighbor of the node.
These fields need to be set correctly especially in the rotations, and whenever performing an insertion or deletion at the leaf level.
The programming language is C or C++; test your code before submission using the gcc or g++ compiler.