void TrainList::load() {
    ifstream file ("trains.txt", std::ifstream::in);
    file.open ("trains.txt", std::ofstream::out | std::ofstream::trunc);
    int n;

    file >> n;
    for(int i = 0; i < n; i++) {
        int trainNumber = 0;
        int arivalTime = 0;
        string destination;
        file >> trainNumber;
        file >> arivalTime;
        file >> destination;

        if(trainWithNumberExists(trainNumber)) {
            continue;
        }

        train* newTrain = new train;

        newTrain->number = trainNumber;
        file >> arivalTime;
        file >> destination;

        list_node* newNode = new list_node;
        newNode->data = newTrain;
        newNode->next = head;

        head = newNode;
    }

    file.close();
}