public static int binarySearch(String[] A, int left, int right, String V) {
        int middle;
        if (left > right) {
            return -1;
        }
        middle = (left + right) / 2;
        int compare = V.compareTo(A[middle]);
        if (compare == 0) {
            return middle;
        }
        if (compare < 0) {
            return binarySearch(A, left, middle - 1, V);
        } else {
            return binarySearch(A, middle + 1, right, V);
        }
    }

    static public String sortedLinearSearch(String[] A, String B) {
        for (int k = 0; k < A.length; k += 2) {
            int compare = A[k].compareTo(B);
            if (compare == 0) {
                return A[k + 1];
            }
        }
        return "The book was not found.";
    }

    private void searchActionPerformed(java.awt.event.ActionEvent evt) {
        ArrayList<String> books = new ArrayList<String>();
        BufferedReader br = null;

        try {
            br = new BufferedReader(new FileReader("BookList.txt"));
            String title;
            while ((title = br.readLine()) != null) {
                books.add(title);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                br.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        String[] bookList = new String[books.size()];
        books.toArray(bookList);

        String[] bookName = new String[books.size() / 2];
        String[] bookNum = new String[books.size() / 2];

        for (int i = 0; i <= books.size() / 2 - 1; i++) {
            bookName[i] = bookList[2 * i + 1];
            bookNum[i] = bookList[2 * i];
            test.append(bookNum[i]);
            test.append(bookName[i] + "\n");
        }



        linearOut.setText(sortedLinearSearch(bookList, refIn.getText()));
        if (binarySearch(bookNum, 0, books.size() / 2 - 1, refIn.getText()) < 0) {
            binaryOut.setText("The boox was not found.");
        } else {
            binaryOut.setText(bookName[binarySearch(bookNum, 0, books.size() / 2 - 1, refIn.getText())]);
        }