dev(narugo): fix a bug

                    outputs = model.diff(dists.reshape(-1, 1))

                    preds = torch.argmax(outputs, dim=1)

                    train_correct += (preds == labels).sum().item()

                    train_fp += (preds[labels == 0] == 1).sum().item()

                    train_fn += (preds[labels == 1] == 0).sum().item()

                    train_total += labels.shape[0]

                    test_correct += (preds == labels).sum().item()

                    test_fp += (preds[labels == 0] == 1).sum().item()

                    test_fn += (preds[labels == 1] == 0).sum().item()

                    test_total += labels.shape[0]

                test_accuracy = test_correct / test_total

                test_fp_p = test_fp / test_total