Suggestions on C++ Inheritence

Question

I have been implementing the Red Black Trees in C++ using inheritence. I have 4 Classes, Node, Tree, RBNode, RBTree.

class Node
{
    protected:
        int data;
        Node *left;
        Node *right;
        Node *parent;
    public:
        Node();
        Node(int data);
        void print_node(ofstream &file);
        Node * find_node(int data);
        void insert_node(Tree *t);
        void left_rotate_node(Tree *t);
        void right_rotate_node(Tree *t);
        void delete_node(Tree *t);
}

class Tree
{
    protected:
        Node * root;
        list<int> treedata;
    public:
        Tree();
        virtual Node * get_root();
        virtual void set_root(Node *root_node);
        void insert_into_tree();
        void delete_from_tree();
        virtual void print_tree();
}

RBNode and RBTree inherit Node, Tree respectively. But I am not able to use the functions of the Node class. For example, the function void Tree::insert_node(Tree *t);

Even in the class RBNode, this function does the same work except that the funntion receives RBTree as the parameter. How can I make use of the same function without redeclaring it in RBNode. I thought of using casting inside function, but how will I know which classes object is calling the function.

Please give me some suggestions. I am new to C++.

Answer 1

Either the inheritance was not properly defined, or there is a confuson on insert_node(Tree *t) which is defined in the Node and not in the Tree.

Anyway, the following minimal code example compiles well:

class Tree; 
class Node
{
protected:
    int data;
    Node *left,*right, *parent;
public:
    Node(int data=0) : data(data), left(nullptr), right(nullptr), parent(nullptr) {}
    void insert_node(Tree *t) { cout << "Insert" << endl; }
};
class Tree
{
protected:
    Node * root;
    list<int> treedata;
public:
    Tree() : root(nullptr) {}
};
class RBSnode : public Node {};  // public inheritance 
class RBStree : public Tree {};  

...
RBSnode n; 
RBStree t; 
n.insert_node(&t); 

Note that in absence of the public inheritance specifier, private inheritance is assumed: within the class you have acces to all the protected and public members of the base class, but outside, the class, you don't see the inherited members. I guess it's what happenned to you.