DoublyLinkedListNode* sortedInsert(DoublyLinkedListNode* llist, int data) {
    DoublyLinkedListNode** cur = &llist;
    DoublyLinkedListNode * new_node = calloc(sizeof(DoublyLinkedListNode), 1);
    new_node->data = data;
    
    while(*cur && ((*cur)->data < data)) {
        cur = &(*cur)->next;
    }
    
    new_node->next = (*cur);
    if(*cur) {
        new_node->prev = (*cur)->prev;
    }
    (*cur) = new_node;
    return llist;
}