Pre Order binary tree build and print

#include <bits/stdc++.h>
using namespace std;
class node {
    public:
    int data;
    node *left;
    node *right;

    node(int d){
        data=d;
        left=NULL;
        right=NULL;
    }
};

node* buildTree(){

    int data;
    cin>>data;
    if(data==-1)
        return NULL;
    node *curr= new node(data);
    curr->left=buildTree();
    curr->right=buildTree();
    return curr;
}

void print(node *curr){
    if(curr==NULL)
        return;

    cout<<curr->data<<" ";
    print(curr->left);
    print(curr->right);
}

int main() {

    node *curr=buildTree();
    print(curr);
    return 0;
}