variables and memory, declaration

#include "stdafx.h"
#include <iostream>
#include <cstdio>
#include <vector>
 
using namespace std;
 
class sam {
public:
    int a;
    int b;
    sam(int z, int w) {
        a = z;
        b = w;
    }
};
 
int main2() {
    sam * test = new sam(1, 2);
    return 0;
}
 
struct node {
    int data;
    node * next;
};
 
void append(int data, node * head) {
    node * hello = new node;
    hello->data = data;
    hello->next = NULL;
    node * tmp = head;
    while (tmp->next != NULL) {
        tmp = tmp->next;
    }
    tmp->next = hello;
}
 
void print(node * head) {
    while (head != NULL) {
        cout << head->data << endl;
        head = head->next;
    }
}
 
int main() {
    vector<int> * v1 = new vector<int>;
    vector<int> v2;
    v1->push_back(1);
    v1->push_back(2);
    v1->push_back(3);
    cout << &v1 << " " << &v2 << endl;
    v2 = *v1;
    cout << &v1 << " " << &v2 << endl;
    cout << v2.at(1) << endl;
    while(1){}
    node head = { 1,NULL };
    append(2, &head);
    append(3, &head);
    append(4, &head);
    append(5, &head);
    print(&head);
    while (1) {}
    return 0;
}