C++  //Precondition: root_ptr points to a binary tree with at least one node //Postcondition: Height of the tree is returned recursively, recall that a tree  // with one node is height of 0 and an empty tree has a height of -1 long bst_height(const binary_tree_node* root_ptr) const; //Precondition: Tree has at least one node, ie height >= 0 //Precondition: Inserts newDataItem into the binary search tree in the correct spot. void bst_insert( const Item& ,binary_tree_node*);