C++ only Write an implementation of the set class, with associated iterators using a binary search tree. Add to each node a link to the next smallest...

C++ only

• Write an implementation of the set class, with associated iterators using a binary search tree.
• Add to each node a link to the next smallest and next largest node.

Note: To make your code simpler, add a header and tail node which are not part of the binary search tree but help make the linked list part of the code simpler.