void push(priority_queue* queue, value_type value, uint remaining_time) {
    priority_queue_item *item;
    item = malloc(sizeof(priority_queue_item));
    item->value = value;
    item->remaining_time = remaining_time;
    item->next = NULL;
    item->previous = NULL;

    if (queue->size != 0) {
        if(item->remaining_time <= queue->first->remaining_time) { // radime na zacatek fronty
            item->previous = queue->first;
        } else { // radime doprostred nebo na konec fronty
            item->next = queue->first;
            while (item->remaining_time > temp->remaining_time && item->next->previous != NULL)
                item->next = item->next->previous;
            item->previous = item->next->previous;
        }
    }

    if (item->next == NULL) {
        queue->first = item;
    } else {
        queue->next->previous = item;
    }

    if (item->previous == NULL) {
        queue->last = item;
    } else {
        queue->previous->next = item;
    }

    queue->size++;
}