Question

This is the code for an upcoming university practical I have:

import java.util.Random;

public class Practical4_Assessed 
{

public static void main(String[] args) 
{

    Random numberGenerator = new Random ();
    int[] arrayOfGenerator = new int[100];
    int[] countOfArray     = new int[10];
    int count;

    for (int countOfGenerator = 0; countOfGenerator < 100; countOfGenerator++)
    {
        count = numberGenerator.nextInt(10);
        countOfArray[count]++;
        arrayOfGenerator[countOfGenerator] = count + 1;
    }

    int countOfNumbersOnLine = 0;
    for (int countOfOutput = 0; countOfOutput < 100; countOfOutput++)
    {
        if (countOfNumbersOnLine == 10)
        {
            System.out.println("");
            countOfNumbersOnLine = 0;
            countOfOutput--;
        }
        else
        {
            if (arrayOfGenerator[countOfOutput] == 10)
            {
                System.out.print(arrayOfGenerator[countOfOutput] + "  ");
                countOfNumbersOnLine++;
            }
            else
            {
                System.out.print(arrayOfGenerator[countOfOutput] + "   ");
                countOfNumbersOnLine++;
            }
        }
    }

    System.out.println("");
    System.out.println("");

    String occurrencesReport = "";
    String graph = "";

    for (int countOfNumbers = 0; countOfNumbers < countOfArray.length; countOfNumbers++)
    {
        occurrencesReport += "The number " + (countOfNumbers + 1) + 
            " occurs " + countOfArray[countOfNumbers] + " times.";

        if (countOfNumbers != 9)
            graph += (countOfNumbers + 1) + "   ";
        else
            graph += (countOfNumbers + 1) + "  ";

        for (int a = 0; a < countOfArray[countOfNumbers]; a++)
        {
            graph += "*";
        }
        occurrencesReport += "\n";
        graph += "\n";
    }

    System.out.println(occurrencesReport);
    System.out.println(graph);

    int max = 0;
    int test = 0;
    for (int counter = 0; counter < countOfArray.length; counter++)
    {
        if (countOfArray[counter] >= max)
        {
            max = countOfArray[counter];
            test = counter + 1;
        }
    }

    System.out.println("The number that appears the most is " + test + ".");

}
}

The program creates an array that will store 100 integers (all of which are between 1 and 10), which are generated by a random number generator, and then print out ten numbers of this array per line. It then scans these integers, counts up how often each number appears and store the results in a second array.
Following this, it outputs a horizontal bar chart of asterisks showing how often each number appears before finally outputting the number that appears the most often.

I thought I had the code totally and completely done, but I’ve just realised that if multiple numbers occur the same amount of times, the last part of my code can’t handle this, e.g. if the numbers 3 and 5 both appears 12 times, the code can only produce one of them.

Does anyone have a way around this?

Thanks,
Andrew

Answer 1

There are a couple of ways to address this, which range from quick to complex. The easiest way is to brute force it like such:

int max = 0;
//int test = 0;
for (int counter = 0; counter < countOfArray.length; counter++)
{
    if (countOfArray[counter] >= max)
    {
        max = countOfArray[counter];
        //test = counter + 1;
    }
}

System.out.print("The number that appears the most is");
boolean first = true;
for(int i = 0; i < countOfArray.length; i++)
{
    if(countOfArray[i] == max)
    {
        if(first)
            first = false;
        else
            System.out.print(",");
        System.out.print(" " + (i+1) );
    }
}
System.out.println(".");

Here’s the output:

6   2   6   5   6   8   9   3   5   8   
9   8   10  10  4   5   8   9   8   5   
1   7   8   5   6   7   10  4   5   4   
2   7   9   2   3   3   1   2   10  3   
5   2   10  1   1   6   3   3   8   10  
2   6   10  2   5   1   4   10  8   7   
7   8   7   3   7   8   3   4   5   5   
7   8   9   8   6   6   8   1   10  3   
2   5   4   6   9   9   10  10  1   10  
9   4   10  9   7   3   4   3   2   4   

The number 1 occurs 7 times.
The number 2 occurs 9 times.
The number 3 occurs 11 times.
The number 4 occurs 9 times.
The number 5 occurs 11 times.
The number 6 occurs 9 times.
The number 7 occurs 9 times.
The number 8 occurs 13 times.
The number 9 occurs 9 times.
The number 10 occurs 13 times.

1   *******
2   *********
3   ***********
4   *********
5   ***********
6   *********
7   *********
8   *************
9   *********
10  *************

The number that appears the most is 8, 10.

There are much cleaner ways to go about it, but hopefully that gives you a decent start!