random

element* insert_sorted(element *first, element *new_elem) {


    if (first==NULL){
        first = new_elem;
        return first;
    }

    if (first!=NULL && ((first->isbn) > (new_elem->isbn))){
        new_elem->next = first;
        first = new_elem;
        return first;
    }

    element *tmp= first;
    element *tmp2= tmp->next;

    if (tmp2 ==NULL) {

        tmp->next = new_elem;
        return first;
    }

    while ((tmp2 != NULL) && ((tmp->isbn) < (tmp2->isbn))){
            tmp2 = tmp2->next;
            tmp = tmp2;
        }

new_elem->next = tmp2;
tmp = new_elem;
return first;
}