Problem
1. Write a method and the corresponding recursive function to traverse a binary tree (in whatever order you find convenient) and dispose of all its nodes. Use destructor this method to implement a Binary_tree destructor.
2. Write a copy constructor
Binary_tree::Binary_tree(const Binary_tree&original)
that will make a copy of a linked binary tree. The constructor should obtain constructor the necessary new nodes from the system and copy the data from the nodes of the old tree to the new one.