Question

Write a Java program called Numbers that reads a file containing a list of numbers and outputs, for each number in the list, the next bigger number. For example, if the list is

78, 22, 56, 99, 12, 14, 17, 15, 1, 144, 37, 23, 47, 88, 3, 19

the output should look like the following:

78: 88

22: 23

56: 78

99: 144

12: 14

14: 15

17: 19

15: 17

1: 3

144: 2147483647

37: 47

23: 37

47: 56

88: 99

3: 12

19: 22

NOTE: If there is no bigger number in the sequence, just display the value of Integer.MAX_VALUE .

The output should be shown on the screen and also saved in a file.

Program Design

• You should have a single class called Numbers.
• You should have a static method called nextLargest, which takes as input an array of integers called list and another single integer called value. It should return the number that is the next larger than the value in the list (as described above). You need to use this method to implement your program.
• The input file from which the list is read should be called "list.txt". Assume it's in the current directory.
• The output file to which the results should be saved should be called "nextlist.txt". Save it in the current directory (i.e. don't specify the path).

Additional Requirements

1. The name of your Java Class that contains the main method should be Numbers. All your code should be within a single file.
2. Your code should follow good coding practices, including good use of whitespace (indents and line breaks) and use of both inline and block comments.
3. You need to use meaningful identifier names that conform to standard Java naming conventions.
4. At the top of the file, you need to put in a block comment with the following information: your name, date, course name, semester, and assignment name.
5. If the input file contains something not in the proper format, your program should handle this gracefully by displaying an appropriate message to the user and closing the program (without letting it crash).

The output of your program should exactly match the sample program output given at the end

Answer 1

/*
 *  Java Program to read integers from a text file and write next largest number of integers to new file
 */

import java.io.*;
import java.util.*;

class Main {

  public static int nextLargest(int list[], int val) {
    int next;
      next = Integer.MAX_VALUE;
      for (int i = 1; i < list.length; i++) {
        if (val < list[i]) {
          next = list[i];
          break;
        }
      }
    return next;
  }

  public static void main(String[] args) throws Exception {

    List<Integer> list = new ArrayList<Integer>();

    File file = new File("list.txt");
    FileWriter fWrite = new FileWriter("nextlist.txt");
    Scanner sc = new Scanner(file);

    while (sc.hasNextInt())
      list.add(sc.nextInt());
    
    int intList[] = new int[list.size()];

    for (int i = 0; i < list.size(); i++) {
      intList[i] = list.get(i);
    }

    for (int i = 0; i < list.size(); i++) {
      System.out.println(list.get(i) + ": " + nextLargest(intList, list.get(i)));
      fWrite.write(list.get(i) + ": " + nextLargest(intList, list.get(i)) + "\n");
    }
    fWrite.close();
  }
}

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