Binary sort number arranging tree

I am having trouble with this. I believe I have found where the problem is with the random couts in the functions. When a node is added it keeps getting added to root node. It won't become a new node. What am I doing wrong? Thanks for any help offered.

Code:

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#include <iostream>

using namespace std;

class Node
{
    public:
        Node(int v);
        ~Node();
             
        int value;
       
        Node* left;
        Node *right;
};

Node::Node(int v)
{
    value = v;
    left = NULL;
    right = NULL;
}

Node::~Node() {}


class BinaryTree
{
    public:
        BinaryTree();
        ~BinaryTree();
       
        void add(int i);
        void display();
       
        void clear();
       
    private:
        Node* root;
       
        void removeNode(Node* n);
        void displayValue(Node* n);
        void insertNode(Node* n, int v);
};

BinaryTree::BinaryTree()
{
    root = NULL;
}

BinaryTree::~BinaryTree()
{
    removeNode(root);
}

void BinaryTree::removeNode(Node* n)
{
    if (n)
    {
        removeNode(n->left);
        removeNode(n->right);
        delete n;
    }
}

void BinaryTree::clear()
{
    removeNode(root);
}

void BinaryTree::display()
{
    cout << "Values: ";
    displayValue(root);
    cout << endl;
}

void BinaryTree::displayValue(Node* n)
{
    if (n)
    {
        if (n->left)
            displayValue(n->left);
        if (n->right)
            displayValue(n->right);
           
        cout << n->value << ", ";
    }
}

void BinaryTree::add(int i)
{
    if (root)
        cout << "root is not null" <<endl;
    else
        cout << "root is null" << endl;
       
    insertNode(root, i);
}

void BinaryTree::insertNode(Node* n, int v)
{
    if (n)
    {
        if (v < n->value)
            insertNode(n->left, v);
        else
            insertNode(n->right, v);
           
        cout << "branch added" << endl;
    }
    else
    {
        n = new Node(v);
        cout << "leaf added" << endl;
    }
}

int main()
{
    BinaryTree Tree;
   
    int response = 0;
    int value;
   
    while (response != 4)
    {
        cout << "1. Add A Number." << endl;
        cout << "2. Display Values." << endl;
        cout << "3. Clear Tree." << endl;
        cout << "4. Exit." << endl;
        cin >> response;
       
        if (response == 1)
        {
            cout << "Value to add: ";
            cin >> value;
            Tree.add(value);
        }
        else if (response == 2)
        {
            Tree.display();
        }
        else if (response == 3)
        {
            Tree.clear();
        }
       
        cout << " ----------------------------- " << endl;

    }
    cin.get();
    return 0;
}

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insertion seems to be OK
problem with displaying

Quote:

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Code:

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void BinaryTree::displayValue(Node* n)
{
    if (n)
    {
        if (n->left)
            displayValue(n->left);
        if (n->right)
            displayValue(n->right);
           
        cout << n->value << ", ";
    }
}

---

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Code:

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        cout << n->value << ", ";

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should be outputted before right node

I don't think displaying is the probem, inserting is.

When root is passed in "insertNode(Node* n, int v);" as insertNode(root, i) the new keyword works only for the prototype "Node* n" but root isn't being set as Node *n. I am sorry for my ignorance with pointers and passing them in functions. I am new with them.

Code:

---

void BinaryTree::add(int i)
{
    if (root)
        cout << "root is not null" <<endl;
    else
        cout << "root is null" << endl;
       
    insertNode(root, i);
}

void BinaryTree::insertNode(Node* n, int v)
{
    if (n)
    {
        if (v < n->value)
            insertNode(n->left, v);
        else
            insertNode(n->right, v);
           
        cout << "branch added" << endl;
    }
    else
    {
        n = new Node(v);
        cout << "leaf added" << endl;
    }
}

---

void BinaryTree::insertNode(Node*& n, int v)


the *& was what the problem was. I am still unsure of what it exactly means.

Also I am not sure if I am deleting all the nodes correctly. Would I also make the remove function be void removeNode(Node*& n); ?

Here is the updated code, it seems to work but this is not what I am doing with trees. I am planning to use binary trees for a way more complex problem, this is just practice. Thanks for all the help provided so far.

Code:

---

#include <iostream>

using namespace std;

class Node
{
    public:
        Node(int v);
        ~Node();
             
        int value;
       
        Node* left;
        Node* right;
};

Node::Node(int v)
{
    value = v;
    left = NULL;
    right = NULL;
}

Node::~Node() {}


class BinaryTree
{
    public:
        BinaryTree();
        ~BinaryTree();
       
        void add(int i);
        void display();
       
        void clear();
       
    private:
        Node* root;
       
        void removeNode(Node* n);
        void displayValue(Node* n);
        void insertNode(Node*& n, int v);
};

BinaryTree::BinaryTree()
{
    root = NULL;
}

BinaryTree::~BinaryTree()
{
    removeNode(root);
}

void BinaryTree::removeNode(Node* n)
{
    if (n)
    {
        removeNode(n->left);
        removeNode(n->right);
        delete n;
        n = NULL;
    }
}

void BinaryTree::clear()
{
    removeNode(root);
}

void BinaryTree::display()
{
    cout << "Values: ";
    displayValue(root);
    cout << endl;
}

void BinaryTree::displayValue(Node* n)
{
    if (n)
    {   
        if (n->left)
            displayValue(n->left);
           
        cout << n->value << ", ";
           
        if (n->right)
            displayValue(n->right);
    }
}

void BinaryTree::add(int i)
{     
    insertNode(root, i);
}

void BinaryTree::insertNode(Node*& n, int v)
{
    if (n)
    {
        if (v < n->value)
            insertNode(n->left, v);
        else
            insertNode(n->right, v);
           
    }
    else
    {
        n = new Node(v);
    }
}

int main()
{
    BinaryTree Tree;
   
    int response = 0;
    int value;
   
    while (response != 4)
    {
        cout << "1. Add A Number." << endl;
        cout << "2. Display Values." << endl;
        cout << "3. Clear Tree." << endl;
        cout << "4. Exit." << endl;
        cin >> response;
       
        if (response == 1)
        {
            cout << "Value to add: ";
            cin >> value;
            Tree.add(value);
        }
        else if (response == 2)
        {
            Tree.display();
        }
        else if (response == 3)
        {
            Tree.clear();
        }

        cout << " ----------------------------- " << endl;
    }
    cin.get();
    return 0;
}

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