Node* p = new Node(); 与 new Node;
int main()
{
Node* p = new Node();
cout << p->data << endl; // 0
p->data = 9;
cout << p->data << endl; // 9
Node* p2 = new Node;
cout << p2->data << endl; // 不确定
p2->data = 91;
cout << p2->data << endl; // 91
return 0;
}