| 10 | public static byte[] bitfield = new byte [(int) (numberOfInts / 8)]; |
| 11 | |
| 12 | public static void findOpenNumber() throws FileNotFoundException { |
| 13 | Scanner in = new Scanner(new FileReader("Chapter 10/Question10_3/input_file_q10_3.txt")); |
| 14 | while (in.hasNextInt()) { |
| 15 | int n = in.nextInt (); |
| 16 | /* Finds the corresponding number in the bitfield by using |
| 17 | * the OR operator to set the nth bit of a byte |
| 18 | * (e.g., 10 would correspond to the 2nd bit of index 2 in |
| 19 | * the byte array). */ |
| 20 | bitfield [n / 8] |= 1 << (n % 8); |
| 21 | } |
| 22 | |
| 23 | for (int i = 0; i < bitfield.length; i++) { |
| 24 | for (int j = 0; j < 8; j++) { |
| 25 | /* Retrieves the individual bits of each byte. When 0 bit |
| 26 | * is found, finds the corresponding value. */ |
| 27 | if ((bitfield[i] & (1 << j)) == 0) { |
| 28 | System.out.println (i * 8 + j); |
| 29 | return; |
| 30 | } |
| 31 | } |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | public static void main(String[] args) throws IOException { |
| 36 | findOpenNumber(); |