preorder_tree_traversal_recursive.c++

// Time Complexity -> O(n) where n is number of nodes in the tree

#include <bits/stdc++.h>
using namespace std;

struct Node
{
    int data;
    struct Node *left;
    struct Node *right;
    Node(int val)
    {
        data = val;
        left = right = NULL;
    }
};

void preOrder(struct Node *root)
{
    if (root == NULL)
    {
        return;
    }

    cout << root->data << " ";
    preOrder(root->left);
    preOrder(root->right);
}

int main()
{
    struct Node *root = new Node(1);
    root->left = new Node(2);
    root->left->left = new Node(4);
    root->left->right = new Node(5);
    root->left->right->left = new Node(6);
    root->right = new Node(3);
    root->right->left = new Node(7);
    root->right->right = new Node(8);
    root->right->right->left = new Node(9);
    root->right->right->right = new Node(10);

    preOrder(root);

    return 0;
}