How to Print Data in Binary Tree Level by Level in C++?

// C++ Program to Print Data in Binary Tree Level by Level 
#include <iostream>
#include <queue>
using namespace std;

// Class for a Node in the binary tree
class Node {
public:
    int data;
    Node* left;
    Node* right;
    
    // Constructor to initialize Node with given value
    Node(int value) {
        data = value;
        left = nullptr;
        right = nullptr;
    }
};

// Class representing a Binary Tree
class BinaryTree {
private:
    // Pointer to the root node of the binary tree
    Node* root;  
    
public:
    // Constructor to initialize the binary tree with a given root node
    BinaryTree(Node* rootNode) : root(rootNode) {}
    
    // Function to perform level order traversal and print nodes level by level
    void printLevelOrder() {
        if (root == nullptr) return;  
        
        // Queue to store nodes for level order traversal
        queue<Node*> q;  
        // Enqueue the root node
        q.push(root);    
        while (!q.empty()) {
            // Get the current level size
            int levelSize = q.size();  
            // Process all nodes at the current level
            for (int i = 0; i < levelSize; ++i) {
                Node* node = q.front();  
                cout << node->data << " ";  
                q.pop();  
                
                // Enqueue left child if it exists
                if (node->left != nullptr)
                    q.push(node->left);
                
                // Enqueue right child if it exists
                if (node->right != nullptr)
                    q.push(node->right);
            }
            // Print new line after each level is processed
            cout << endl;  
        }
    }
};

int main() {
    // Create nodes for the binary tree
    Node* root = new Node(10);
    root->left = new Node(20);
    root->right = new Node(30);
    root->left->left = new Node(40);
    root->left->right = new Node(50);
    root->right->left = new Node(60);
    root->right->right = new Node(70);
    
    // Create a binary tree instance with the root node
    BinaryTree btree(root);
    
    // call the printlevel order function to print the data of binary tree level by level
    cout<<"Data of the Binary tree Level by Level:"<<endl;
    btree.printLevelOrder();
    
    return 0;
}