Question

Write a complete program to do the following: The main program calls a method to read in (from an input file) a set of people's three-digit ID numbers and their donations to a charity (hint: use parallel arrays). Then the main program calls a method to sort the ID numbers into numerical order, being sure to carry along the corresponding donations. The main program then calls a method to print the sorted lists in tabular form, giving both ID numbers and donations. Then the main program calls another method to sort the donation amounts into descending order, carrying along the corresponding ID numbers. It then, once again, prints the sorted lists, giving both ID numbers and donations. Finally it prints some statistics (see below). Here are the details:

The main program calls a method to read in the data from a file. The data consists of sets of lines of data, each of which contains a person's three-digit integer ID number and a donation in dollars and cents. (e.g., 456 250.00 or 123 175.34). The file is read until end-of-file is reached. The method returns how many sets of data were read in. The main program calls the return value donorCount. The main program calls these arrays idNumbers and donations. A separate printing method prints the original set of data in the form of a neat table (use printf). When the arrays print, there should be an overall heading, plus headings for the columns of ID numbers and donations.
Then the main program sends the array of ID numbers, the array of donations, and the size donorCount to a sorting method. This method sorts the ID numbers into numerical order using a selection (linear) sort. Be sure to maintain the match-up of ID numbers and donations. For example, 456 should always be associated with 250.00, no matter where 456 moves in numerical order; similarly, 123 should stay with 175.34. When the sorting method finishes and returns control to the main program, the main program calls the printing method to once again print the two arrays.
Next, the main program sends the same three parameters to the second sorting method, which sorts the donations into descending numerical order (using a bubble sort), being sure to maintain the linkup of ID numbers and donations. When this sorting method finishes and returns control to the main program, the main program, once again, calls the printing method to print the two arrays with appropriate headings. Your arrays should have room for up to 50 entries. To test the program, have a set of data with at least 15 to 20 values in each array. Make sure that your original order is not close to numerical order for either array and that the two numerical orders are not close to each other.
(NOTE: Why can’t you use the same sorting method for the two sorts???)
Finally, print statistics as follows, based on the array sorted by donation:
The id and donation amount of the highest donor (this is easy once the array is sorted!); and the median donation value, which is the middle value for an odd number of donors (e.g. for 5 donors it would be the donation value of the third) or the average of the two middle donors (e.g. for 6 donors it would be the average of the 3rd and 4th). Your program doesn’t "know" the value of donorCount so you have to check. It should work for even or odd. Also calculate and print the average donation amount.
All donation values should be printed with precision of two decimal places. Columns should be neatly aligned, so format your output carefully.
Print your input file and submit it with your program.

Answer 1

See explaination

Step-by-step explanation:

import java.io.File;

import java.io.FileNotFoundException;

import java.util.Scanner;

public class Donor {

public static void main(String[] args){

int idNumbers[] = new int[50]; //created two array each of 50 size

int donations[] = new int[50];

int donorCount=readFile(idNumbers, donations); //calling readfile function

System.out.println("--------------------Original record--------------------");

printDetails(idNumbers,donations,donorCount); //printing details

sortByDonorId(idNumbers,donations,donorCount);

System.out.println("--------------------Sort by donor id--------------------");

printDetails(idNumbers,donations,donorCount);

sortByDonation(idNumbers,donations,donorCount);

System.out.println("--------------------Sort by donation amount--------------------");

printDetails(idNumbers,donations,donorCount);

}

private static void sortByDonation(int[] idNumbers, int[] donations, int donorCount) {

for(int i=0;i<=donorCount;i++){

for(int j=i+1;j<=donorCount;j++){

if(donations[i]>donations[j]){ //comparison based on donations

int temp = idNumbers[i];

idNumbers[i] = idNumbers[j];

idNumbers[j] = temp;

temp = donations[i];

donations[i] = donations[j];

donations[j] = temp;

}

}

}

}

private static void sortByDonorId(int[] idNumbers, int[] donations, int donorCount) {

for(int i=0;i<=donorCount;i++){

for(int j=i+1;j<=donorCount;j++){

if(idNumbers[i]>idNumbers[j]){ //comparison based on donor number

int temp = idNumbers[i];

idNumbers[i] = idNumbers[j];

idNumbers[j] = temp;

temp = donations[i];

donations[i] = donations[j];

donations[j] = temp;

}

}

}

}

public static void printDetails(int[] idNumbers, int[] donations, int donorCount){

System.out.printf("%-5s%s"," ","Donor information"); //using printf for format output

System.out.printf("\\%-20s%-20s","ID number","donations");

for(int i=0;i<=donorCount;i++){

System.out.printf("\\%-20s%-20s",idNumbers[i],donations[i]);

}

System.out.println();

}

public static int readFile(int idNumbers[],int donations[]){

File file = new File("input.txt"); //reading data from this file

Scanner reader;

int donorIndex=-1; //keep track of number of records

try {

reader = new Scanner(file);

while(reader.hasNext()){

donorIndex++;

String line = reader.nextLine();

idNumbers[donorIndex] = Integer.parseInt(line.split(" ")[0]); //spliting line by space,0 is idnumber

donations[donorIndex] = Integer.parseInt(line.split(" ")[1]); //spliting line by space,1 is donations

}

reader.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return donorIndex;

}

}