#include "linkedlist.h"                                                                   

Node * appendnode(Node *begin, Node *pos, Node *newnode)
{
    if ((begin != NULL) && (pos != NULL) && (newnode != NULL))
    {   
        newnode -> next = pos -> next;
        pos -> next = newnode;
    }   
    else if (begin == NULL)
    {   
        begin = pos = newnode;
    }   

    return(begin);
}