c++ tree data structure

//tree.cpp
#pragma once
#include <iostream>

class node
{
public:
    int data;
    node *left;
    node *right;
    node(int val)
    {
        data = val;
        left = NULL;
        right = NULL;
    }

    node *insert(node *root, int val)
    {
        //
        if (root == NULL)
        {
            return get_new_node(val);
        }

        else if (root->data < val)
        {
            root->right = insert(root->right, val);
        }
        else if (root->data > val)
        {
            root->left = insert(root->left, val);
        }
        return root;
    }

    node *get_new_node(int val)
    {
        node *new_node = new node(val);
        new_node->data = val;
        new_node->left = NULL;
        new_node->right = NULL;
        return new_node;
    }

    node *search(node *root, int key)
    {
        if (root == NULL || root->data == key)
        {
            return root;
        }
        else if (root->data < key)
        {
            return search(root->right, key);
        }
        return search(root->left, key);
    }
    
    void traverse_pre_order(node *node)
    {
        if (node != NULL)
        {
            std::cout << node->data << "\t";
            traverse_pre_order(node->left);
            traverse_pre_order(node->right);
        }
    }

    void traverse_in_order(node *node)
    {
        if (node != NULL)
        {
            traverse_in_order(node->left);
            std::cout << "\t" << node->data;
            traverse_in_order(node->right);
        }
    }

    void traverse_post_order(node *node)
    {
        if (node != NULL)
        {
            traverse_post_order(node->left);
            traverse_post_order(node->right);
            std::cout << "\t" << node->data;
        }
    }
};


//main.cpp
#include <atomic>
#include <chrono>
#include <cmath>
#include <cstddef>
#include <forward_list>
#include <functional>
#include <future>
#include <iomanip>
#include <iostream>
#include <latch>
#include <list>
#include <map>
#include <mutex>
#include <queue>
#include <random>
#include <stack>
#include <string>
#include <thread>
#include <utility>
#include <uuid/uuid.h>
#include <vector>
#include "tree.cpp"
 
char *uuid_value = (char *)malloc(40);
char *get_uuid_value()
{
    uuid_t new_uuid;
    uuid_generate(new_uuid);
    uuid_unparse(new_uuid, uuid_value);
    return uuid_value;
}

std::string get_time_now(bool is_exact = false)
{
    std::stringstream ss;
    std::chrono::time_point<std::chrono::high_resolution_clock> now = std::chrono::high_resolution_clock::now();
    time_t raw_time = std::chrono::high_resolution_clock::to_time_t(now);
    struct tm tm_info = *localtime(&raw_time);
    ss << std::put_time(&tm_info, "%Y%m%d%H%M%S");
    if (is_exact)
    {
        std::chrono::seconds seconds = std::chrono::duration_cast<std::chrono::seconds>(now.time_since_epoch());
        std::chrono::milliseconds mills = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch());
        std::chrono::microseconds micros = std::chrono::duration_cast<std::chrono::microseconds>(now.time_since_epoch());
        std::chrono::nanoseconds nanos = std::chrono::duration_cast<std::chrono::nanoseconds>(now.time_since_epoch());
        ss << "_" << std::setw(3) << std::setfill('0') << (mills.count() - seconds.count() * 1000)
           << std::setw(3) << std::setfill('0') << (micros.count() - mills.count() * 1000)
           << std::setw(3) << std::setfill('0') << (nanos.count() - micros.count() * 1000);
    }
    return ss.str();
}


void tree_demo()
{
    node *root=new node(1);
    root->left=new node(2);
    root->right=new node(3);
    root->left->left=new node(4);
    std::cout<<"PreOrder traversal: "; 
    root->traverse_pre_order(root);
    std::cout<<std::endl;
    std::cout<<"Inorder traversal: ";
    root->traverse_in_order(root);
    std::cout<<std::endl;
    std::cout<<"PostOrder traversal: ";
    root->traverse_post_order(root);
    std::cout<<std::endl;
    std::cout<<"Finish in "<<__FUNCTION__<<std::endl;
}

int main(int args, char **argv)
{ 
    tree_demo();
    std::cout << get_time_now(true) << ",thread id:" << std::this_thread::get_id() << ",in " << __FUNCTION__ << std::endl;
}

g++-12 -std=c++2a -I. *.cpp -o h1 -luuid -lpthread

./h1