Question

Write a program that reads a file name from the keyboard. The file contains integers, each on a separate line. The first line of the input file will contain the number of integers in the file. You then create a corresponding array and fill the array with integers from the remaining lines. If the input file does not exist, give an appropriate error message and terminate the program. After integers are stored in an array, your program should call the following methods in order, output the intermediate results and count statistics on screen, and at end output even integers and odd integers to two different files called even.out and odd.out.
Implement the following methods in the program:
* public static int[] inputData() – This method will ask user for a file name, create an array, and store the integers read from the file into the array. If input file does not exist, give an appropriate error message and terminate the program.
* public static void printArray(int[] array) – This method will display the content of the array on screen. Print 10 integers per line and use printf method to align columns of numbers.
public static void reverseArray(int[] array) – This method will reverse the elements of the array so that the 1st element becomes the last, the 2nd element becomes the 2nd to the last, and so on.
* public static int sum(int[] array) – This method should compute and return the sum of all elements in the array.
* public static double average(int[] array) – This method should compute and return the average of all elements in the array.
* public static int max(int[] array) – This method should find and return the largest value in the array.
* public static int min(int[] array) – This method should find and return the smallest value in the array.
* public static void ascendingSelectionSortArray(int[] array) – This method will use Selection Sort to sort (in ascending order) the elements of the array so that the 1st element becomes the smallest, the 2nd element becomes the 2nd smallest, and so on.
* public static void desendingBubbleSortArray(int[] array) – This method will Bubble Sort to sort (in descending order) the elements of the array so that the 1st element becomes the largest, the 2nd element becomes the 2nd largest, and so on.
* public static void outputData(int[] array) – This method will create two output files called even.out and odd.out. Scan through the entire array, if an element is even, print it to even.out. If it is odd, print the element to odd.out.

Answer 1

Answer:

Explanation:

import java.util.Scanner;

import java.io.*;

public class ArrayProcessing

{

public static void main(String[] args) throws IOException

{

Scanner kb = new Scanner(System.in);

String fileName;

System.out.print("Enter input filename: ");

fileName = kb.nextLine();

File file = new File(fileName);

if(!file.exists())

{

System.out.println("There is no input file called : " + fileName);

return;

}

int[] numbers = inputData(file);

printArray(numbers);

}

public static int[] inputData(File file) throws IOException

{

Scanner inputFile = new Scanner(file);

int index = 1;

int size = inputFile.nextInt();

int[] values = new int[size];

while(inputFile.hasNextInt() && index < values.length)

{

values[index] = inputFile.nextInt();

index++;

}

inputFile.close();

return values;

}

public static void printArray(int[] array)

{

int count = 1;

for (int ndx = 1; ndx < array.length; ndx++)

{

System.out.printf("%5.f\n", array[ndx]);

count++;

}

if(count == 10)

System.out.println("");

}

}