[C++] add_node

#include<iostream>
#include<cstdlib>
#include<string>
using namespace std;
class node
{
    public:
    int num;
    node *next;
    node()
    {
        num=0;
        next=NULL;
    } 
};
node *add_node(node *mylist,int data)
{
    node *temp_node=mylist;
    if(mylist==NULL)
    {
        mylist=new node;
        mylist->num=data;
        return mylist;
    }
    while(temp_node->next!=NULL)
    {
        temp_node=temp_node->next;
    }
    temp_node->next=new node;
    temp_node->next->num=data;
    return mylist;
}
void show(node *mylist)
{
    while(mylist!=NULL)
    {
        cout<<mylist->num<<"\n";
        mylist=mylist->next;
    }
    return;
}
int main()
{
    node *list=NULL;
    for(int i=0;i<5;i++)
    {
        list=add_node(list,i);
    }
    show(list);
    system("pause");
    return 0;
}