preordertraversal.cpp

#include <iostream>
using namespace std;
 
// Data structure to store a binary tree node
struct Node
{
    int data;
    Node *left, *right;
 
    Node(int data)
    {
        this->data = data;
        this->left = this->right = nullptr;
    }
};
 
// Recursive function to perform preorder traversal on the tree
void preorder(Node* root)
{
    // if the current node is empty
    if (root == nullptr) {
        return;
    }
 
    // Display the data part of the root (or current node)
    cout << root->data << " ";
 
    // Traverse the left subtree
    preorder(root->left);
 
    // Traverse the right subtree
    preorder(root->right);
}
 
 
int main()
{
    /* Construct the following tree
               1
             /   \
            /     \
           2       3
          /      /   \
         /      /     \
        4      5       6
              / \
             /   \
            7     8
    */
 
    Node* root = new Node(1);
    root->left = new Node(2);
    root->right = new Node(3);
    root->left->left = new Node(4);
    root->right->left = new Node(5);
    root->right->right = new Node(6);
    root->right->left->left = new Node(7);
    root->right->left->right = new Node(8);
 
    preorder(root);
 
    return 0;
}