c++ print binary treenode

To print a binary tree in C++, you can follow these steps:

1. Define the structure for a tree node:

struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

1. Implement a function to print the binary tree:

void printBinaryTree(TreeNode* root) {
    if (root == nullptr) {
        return;
    }

    // Print the value of the current node
    cout << root->val << " ";

    // Print the left subtree
    printBinaryTree(root->left);

    // Print the right subtree
    printBinaryTree(root->right);
}

1. Call the printBinaryTree function with the root of the binary tree:

int main() {
    // Create the binary tree
    TreeNode* root = new TreeNode(1);
    root->left = new TreeNode(2);
    root->right = new TreeNode(3);
    root->left->left = new TreeNode(4);
    root->left->right = new TreeNode(5);

    // Print the binary tree
    printBinaryTree(root);

    return 0;
}

This will print the binary tree in preorder traversal, which means the root node is printed first, followed by the left subtree, and then the right subtree.