Can anybody crack this..........?

[java_Slude]

Write, compile, and run a program to do the following. Add comments to each class and each method in the standard form (javadoc-compatible). Remember to define all variables at the beginning of each method. Submit the source files as a Reply to this posting.

1. Write a static method displayArrayAsTable which takes three parameters: an array of integers, the number of elements in the array, and the number of integers to be displayed per line. The method should display the elements of the array in a table of the given number of integers per line (the last line may have to be shorter).

2. In the main method:
• Prompt the user for the number of integer values to sort.
• Create an array of the entered size.
• Randomly generate the given number of integers and store the integers in the array.
• Display the array of integers in a table of 10 integers per line using displayArrayAsTable.
• Copy the array into another array. Sort the second array using selection sort. Display the name of the sort and its running time. Display the sorted array in a table of 8 integers per line using displayArrayAsTable.
• Copy the array into yet another array using insertion sort. Display the name of the sort and its running time. Display the sorted array in a table of 7 integers per line using displayArrayAsTable.
• Copy the array into yet another array. Sort the second array using bubble sort. Display the name of the sort and its running time. Display the sorted array in a table of 9 integers per line using displayArrayAsTable.

[mikeBarr81]

I'm sure there are many people who can "crack" that, but I seriously doubt you'll find any who'll post you the answer! lol

[DJDaveMark]

Have you tried asking your Tutor/Lecturer for help on this marked assessment?

[java_Slude]

He has helped me all he said he would.........what I do not understand is the sort methods. I was never taught them and this guys a big *** and expects me to be able to learn them somewhere. This is the code I have got together so far...
public class LabFour
{
public static void main(String[] args)
{
// instance fields
String input;
int number, numbers, i;
Random generator;
int []intialArray;


// gets the input from the user
input = JOptionPane.showInputDialog
("How many elements do you wish to have? ");
number = Integer.parseInt(input);

// generates random numbers rolled for the amount the user input
intialArray = new int [number];
generator = new Random();
for (i = 0; i < number; i++)
{
numbers = 1 + generator.nextInt(number);
intialArray[i] = numbers;
}



}

public static void displayArrayAsTable(int[] a, int numE, int numD)
{
int i;
for (i = 0; i < numE; i++)
{
System.out.print(a[i]);
if ( i % numD == 0 )
System.out.println();
}
}


However when I try to show the first table of 10 numbers I get an error trying to output the static method displayArrayAsTable. Please someone help me out I would greatly appreciate it. Thank you.

[DJDaveMark]

I fiddled with your code for a bit to get it working, but i had to comment out some of your code as i didn't have the Random class to work with, so i used some number literals.

public class LabFour
{
    public static void main(String[] args)
    {
        // instance fields
        String input;
        int number, numbers = 0, i;
        //Random generator;
        int []intialArray;

        /* gets the input from the user
        input = JOptionPane.showInputDialog
                ("How many elements do you wish to have? "); */
        number = 5;  //Integer.parseInt(input);

        // generates random numbers rolled for the amount the user input
        intialArray = new int [number];
        //generator = new Random();
        
        for (i = 0; i < number; i++)
        {
            numbers = 1 + 1; //generator.nextInt(number);
            intialArray[i] = numbers;
        }
        
        displayArrayAsTable(intialArray, number, numbers);
    }
    
    public static void displayArrayAsTable(int[] a, int numE, int numD)
    {
        int i;
        
        for (i = 0; i < numE; i++)
        {
            System.out.print(a[i]);
            if ( i % numD == 0 )
            System.out.println();
        }
    }
}

Hope that helps, you should be able to tweak it from there!

Cheers, DJDaveMark

[cjard]

Originally posted by DJDaveMark

        for (i = 0; i < numE; i++)
        {
            System.out.print(a[i]);
            if ( i % numD == 0 )
            System.out.println();
        }

recommend:

        for (i = 0; i < numE; i++)
        {
            System.out.print( (a[i]>9?a[i]:" "+a[i])  + ", ");
            if ( i % numD == 0 )
            System.out.println();
        }

for array {1, 17, 5, 99, 2, 13, 67, 7, 97, 34, 22, 35, 41, 68, 12, 8}

output:

old: 11759921367797
     3422354168128
new:  1, 17,  5, 99,  2, 13, 67,  7, 97, 
     34, 22, 35, 41, 68, 12,  8

[java_Slude]

thanks for the code but I have figured out most of it.......can somebody tell me if this looks ok...?



import javax.swing.JOptionPane;
import java.util.Random;


/*
Name: Devin Howton
Date: February 17th, 2004
Assignment: Create a program that will fill an array with random
numbers which we will then place by value in a new
array.
*/


public class LabFour
{

public static void main(String[] args)
{
// instance fields
String input;
int number, numbers, i, temp, j;
Random generator;
int []intialArray;
int []selectionArray;
int []insertionArray;
int []bubbleArray;


// gets the input from the user
input = JOptionPane.showInputDialog
("How many elements do you wish to have? ");
number = Integer.parseInt(input);

// generates random numbers rolled for the amount the user input
intialArray = new int [number];
generator = new Random();
for (i = 0; i < number; i++)
{
numbers = generator.nextInt(number);
intialArray[i] = numbers;
}

// copies the array into another array which will
// sort using the selection sort method.
selectionArray = new int [number];
for (i = 0; i < number; i++)
{
selectionArray[i] = intialArray[i];
}

for (i = 0; i < selectionArray.length - 1; i++)
{
for (j = i+1; j < selectionArray.length; j++)
{
if (selectionArray[i] > selectionArray[j])
{
temp = selectionArray[i];
selectionArray[i] = selectionArray[j];
selectionArray[j] = temp;
}
}
}

// copies the array into another array which will
// sort using the insertion sort method.
insertionArray = new int [number];
for (i = 0; i < number; i++)
{
insertionArray[i] = selectionArray[i];
}

for (i = 1; i < insertionArray.length; i++)
{
boolean inserted = false;
j = i;
while ((j >= 1) && (inserted == false))
{
if (insertionArray[j] < insertionArray[j-1])
{
insertionArray[j] = insertionArray[j-1];
insertionArray[j-1] = insertionArray[j];
}
else
{
inserted = true;
j--;
}
}
}

// copies the array into another array which will
// sort using the bubble sort method.
bubbleArray = new int [number];
for (i = 0; i < number; i++)
{
bubbleArray[i] = insertionArray[i];
}

int n = bubbleArray.length;
boolean notDone = true;
while (notDone)
{
n--;
notDone = false;
for (i=0; i < n; i++)
{
if (bubbleArray[i] > bubbleArray[i+1])
{
temp = bubbleArray[i];
bubbleArray[i] = bubbleArray[i+1];
bubbleArray[i+1] = temp;
notDone = true;
}
}
}




// displays first array of numbers not sorted
displayArrayAsTable(intialArray, number, 10);
System.out.println();
displayArrayAsTable(selectionArray, number, 8);
System.out.println();
displayArrayAsTable(insertionArray, number, 7);
System.out.println();
displayArrayAsTable(bubbleArray, number, 9);



}

public static void displayArrayAsTable(int[] a, int numE, int numD)
{
int i;
for (i = 0; i < numE; i++)
{
if ( i % numD == 0 )
System.out.println();
System.out.print(a[i] + " ");
}
}
}