Array help!

sarahh · November 9th, 2006, 01:53 AM

Hi everyone,

I've been struggling with setting up the arrays in the following problem:

The problem says: Write a program that reads a file consisting of students' test scores in the range 0-200. It should then determine the number of students having scores in each of the following ranges: 0-24, 25-49, 50-74, 75-99, 100-124, 125-149, 150-174, and 175-200. Output the score ranges and the number of students. (Run your program with the following input data: 76, 89, 150, 135, 200, 76, 12, 100, 150, 28, 178, 189, 167, 200, 175, 150, 87, 99, 129, 149, 176, 200, 87, 35, 157, 189.)

I can set up the program but not the array...

Code:

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

public class Scores {

    static final int MAX_SCORE = 200;
    static final int CATEGORY_DIFFERENCE = 25;

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

        int[] categories = new int[MAX_SCORE/CATEGORY_DIFFERENCE];

        Scanner inFile = new Scanner(new FileReader("a:\\testscores.txt"));

        while(inFile.hasNext()) {
            int score = inFile.nextInt();

          categories[(score==MAX_SCORE)?categories.length-1:score/CATEGORY_DIFFERENCE]++;

        }

    inFile.close();

    }
}

ciderpunx · November 22nd, 2006, 08:16 AM

Works here. I added a bit to have it print its results:

Code:

// ...
inFile.close();
for (int i=0;i<categories.length;i++) {
    System.out.println("Category " + (i+1) + " had " + categories[i] + " students")  
}
// ...

Prints:

Code:

charlie@charlie:~$ java Scores
Category 1 had 1 students
Category 2 had 2 students
Category 3 had 0 students
Category 4 had 6 students
Category 5 had 1 students
Category 6 had 3 students
Category 7 had 5 students
Category 8 had 8 students
charlie@charlie:~$ java -version
java version "1.5.0_08"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_08-b03)
Java HotSpot(TM) Client VM (build 1.5.0_08-b03, mixed mode, sharing)
charlie@charlie:~$ uname -a
Linux charlie 2.6.17-2-k7 #1 SMP Wed Sep 13 17:18:46 UTC 2006 i686 GNU/Linux
charlie@charlie:~$

HTH

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