#include <iostream>

using namespace std;

struct Node
{
    int data;
    Node *left;
    Node *right;

    Node() {;}
    Node(int constData)
    {
        data = constData;
        left = NULL;
        right = NULL;
    }
};

void addElement(Node *&root, int myData)
{
    if(root == NULL)
    {
        root = new Node(myData);
        return;
    }

    else if(myData < root->data)
        addElement(root->left, myData);
    else
        addElement(root->right, myData);
}

void preOrderPrint(Node *root)
{
    if(root != NULL)
    {
        cout << root->data << " ";
        preOrderPrint(root->left);
        preOrderPrint(root->right);
    }
}

void postOrderPrint(Node *root)
{
    if(root != NULL)
    {
        preOrderPrint(root->left);
        preOrderPrint(root->right);
        cout << root->data << " ";
    }
}

void inOrderPrint(Node *root)
{
    if(root != NULL)
    {
        preOrderPrint(root->left);
        cout << root->data << " ";
        preOrderPrint(root->right);
    }
}

int countNodes(Node *root)
{
    if(root == NULL)
    {
        cout << "Empty tree\n";
        return 0;
    }
    else
    {
        static int count = 1;

        count += countNodes(root->left);
        count += countNodes(root->right);

        return count;
    }
}

int main(void)
{
    Node *root;
    root = NULL;
    addElement(root, 100);
    addElement(root, 90;
    addElement(root, 110);
    inOrderPrint(root);
    cout << countNodes(root) << "\n";
    cin.get();
    return 0;
}