C++ BST addnote changes - c++

Question

I have this simple question.
In the main function I do: bsearch_tree bs1; I announce on BST tree. Then I add nodes to that tree.
Then I announce on another BST tree: bsearch_tree bs2; and I add nodes(different) to it once again.
What it does, is adding to both tress bs1 and bs2 the same nodes.
For, when I print both trees I see that they are the same but they shouldn't be. It's wrong.
I tried to debug and found that when I add nodes it adds them to the same tree.
I somehow need to make the trees distinct.
I guess I have to make new instance of the class bsearch_tree but I can't change the Main function (limitation).
Here is the Header file:
#include<iostream>
using namespace std;
class tnode
{
private:
double data;
tnode *left;
tnode *right;
public:
tnode(double key);
friend class bsearch_tree;
friend void assist(tnode *tmp);
friend ostream& operator<<(ostream& stream,tnode const *root);
};
class bsearch_tree
{
tnode *root;
public:
bsearch_tree();
bsearch_tree(int);
void duplicate_tree(tnode *root,tnode **new_root);
void free_tree(tnode *node);
void add_value(double v);
tnode copy(tnode *root);
bsearch_tree operator + (const bsearch_tree & t);
bsearch_tree & operator=(const bsearch_tree & v);
friend void print(bsearch_tree tree);
friend ostream& operator<<(ostream& stream,bsearch_tree const root);
private:
void AddNode(double key,tnode *leaf);
void SumTree(tnode *tree);
};
And here is the Code file:
#include<iostream>
#include "head.h"
using namespace std;
tnode::tnode(double key)
{
this->data = key;
this->left = NULL;
this->right = NULL;
}
bsearch_tree::bsearch_tree()
{
bsearch_tree *root = new bsearch_tree(NULL);
//root = NULL;
}
bsearch_tree::bsearch_tree(int)
{
//bsearch_tree *root = new bsearch_tree(NULL);
root = NULL;
}
void bsearch_tree::duplicate_tree(tnode *root,tnode **new_root)
{
if(root == NULL)
return;
(**new_root) = copy(root);
}
tnode bsearch_tree::copy(tnode *root)
{
tnode* node = new tnode(root->data);
if(root == NULL)
return *node;
copy(root->left);
copy(root->right);
return *node;
}
void bsearch_tree::free_tree(tnode *node)
{
if(node == NULL)
return;
free_tree(node->left);
free_tree(node->right);
free(node);
}
void bsearch_tree::add_value(double v)
{
tnode *tmp;
if(root == NULL)
{
tmp = new tnode(v);
root = tmp;
}
else
AddNode(v,root);
}
void bsearch_tree::AddNode(double key,tnode *leaf)
{
if(key >= leaf->data)
{
if(leaf->right != NULL)
AddNode(key,leaf->right);
else
{
tnode * n = new tnode(key);
leaf->right = n;
}
}
else
{
if(leaf->left != NULL)
AddNode(key,leaf->left);
else
{
tnode * n = new tnode(key);
leaf->left = n;
}
}
}
void print(bsearch_tree tree)
{
assist(tree.root);
}
void assist(tnode *tmp)
{
if(tmp)
{
assist(tmp->left);
cout << tmp->data << endl;
assist(tmp->right);
}
}
ostream & operator << (ostream & stream,bsearch_tree const root)
{
print(root);
return stream;
}
bsearch_tree bsearch_tree::operator + (const bsearch_tree & t)
{
bsearch_tree bs;
SumTree(t.root);
return *this;
}
void bsearch_tree::SumTree(tnode *tree)
{
if(tree)
{
AddNode(tree->data,root);
SumTree(tree->left);
SumTree(tree->right);
}
}
bsearch_tree & bsearch_tree::operator = (const bsearch_tree & v)
{
if(this == &v)
return *this;
root = v.root;
return *this;
}
int main()
{
bsearch_tree bs1;
bs1.add_value(16.0);
bs1.add_value(14.0);
bs1.add_value(6.0);
bs1.add_value(18.0);
bs1.add_value(17.0);
bs1.add_value(4.0);
bs1.add_value(5.0);
bs1.add_value(1.0);
bs1.add_value(26.0);
bs1.add_value(22.0);
cout << "bs1:" << endl;
print(bs1);
bsearch_tree bs2;
bs1 = bs1 = bs1;
bs2 = bs1;
bs2.add_value(40.0);
bs2.add_value(20.0);
bs2.add_value(60.0);
cout << "cout << bs2" << endl;
cout << bs2;
bsearch_tree bs3;
//bs3 = bs1 + bs2;
bs3 = bs1;
cout << "cout << bs3" << endl;
cout << bs3;
cin.get();
return 0;
} // main
So my question is: In main function I do bsearch_tree bs1; and then I add some nodes to it, like this: bs1.add_value(16.0); then I do bsearch_tree bs2; and again I add some nodes to it.
Then I print both trees bs1 and bs2 and I find them equal which isn't right.
How do I make the add_value method to add nodes to distinct trees ?
So when I print both trees I will get different trees as the nodes I've entered are different at the first place.
Thanks

Answer 1

Your operator= is incorrect. You're setting a root to point to the same root of the second tree. So from the point of using this operator (e.g., in bs2 = bs1;) both of your trees address the same shared data. You need to implement the assignment operator in a way that will create a copy of the tree data.