I have been working on this assignment for a while now and I can't figure this one issue out. I was given four files, Name.java, SortableArrayList.java, NameListDriver.java, and SortableArrayListWithBubbleSort.java. The program is meant to take a text file with a list of names and sort them alphabetically. Part one of the assignment was to change the bubble sort to a recursive selection sort. I seem to have completed that part as I am able to sort the list of names. The second part requires me to make a driver that does the following things: • Creates a reference to an object in the abstract class SortableArrayList<Integer>, fill an array with random integers, output the array before sorting, then sort the array and output the sorted array. The size of the array is determined by a command line argument. It is supposed to be sorted by the same method that sorts the text file. I am able to create the array of random integers and output them, but I cant sort them.
Here is what i have so far for the driver
import java.util.*;
import java.io.*;
import java.util.Arrays;
class randomDriver<T extends Comparable<T>>
{
public static void main (String args[])
{//start main
int capacity = Integer.parseInt(args[0]);
int[] listItem = new int[capacity];
int lowIndex;
Random generator = new Random();
//fills array with random integers
for (int i = 0; i < listItem.length; i++)
{//for
listItem[i] = (generator.nextInt(1000) + 1);
}//for
SortableArrayList nameList = new SortableArrayListWithSelectionSortII(capacity);
//output array before sort
System.out.println("List of numbers before sort:\n");
System.out.println(Arrays.toString(listItem));
//sort array and display
nameList.sort(); //sort list
System.out.println("\nList of numbers after sort:\n");
System.out.println(Arrays.toString(listItem));
}//end main
}//end class
Here is the sortableArrayListWithSelectionSortII.java that handles the sorting
//class that uses a selection sort to sort the text file of names
class SortableArrayListWithSelectionSortII<T extends Comparable<T>>
extends SortableArrayList<T>
{
public SortableArrayListWithSelectionSortII(int capacity)
{
super(capacity);
}
// sortSublist method
protected void sortSublist(int lowIndex, int highIndex)
{//start sortSublist
if (lowIndex < highIndex)
{//start if
for (int i = lowIndex; i < highIndex; i++)
{ //start for
System.out.println("sortSublist is linked");
int indexOfNextSmallest = getIndexOfSmallest(listItem, i, highIndex-1);
swap(listItem, i, indexOfNextSmallest);
}//end for
sortSublist(lowIndex, highIndex - 1);//recursive call
}// end if
} //end sortSublist
private static <T extends Comparable<T>>
int getIndexOfSmallest(T[] listItem, int first, int last)
{
T min = listItem[first];
int indexOfMin = first;
for (int i = first + 1; i <= last; i++)
{
if (listItem[i].compareTo(min) < 0)
{
min = listItem[i];
indexOfMin = i;
} // end if
// Assertion: min is the smallest of a[first] through a[index].
} // end for
return indexOfMin;
} // end getIndexOfSmallest
private static void swap(Object[] listItem, int i, int j)
{
Object temp = listItem[i];
listItem[i] = listItem[j];
listItem[j] = temp;
} // end swap
} // end SortArray
Here is the SortableArrayList.Java that has some of the classes that I am using
abstract class SortableArrayList<T extends Comparable<T>>
{
protected T[] listItem;
protected int itemCount;
private static int DEFAULT_CAPACITY = 50;
private boolean isSorted;
// Constructs a list with the specified capacity
public SortableArrayList(int capacity)
{
@SuppressWarnings("unchecked")
T[] tempList = (T[]) new Comparable[DEFAULT_CAPACITY];
listItem = tempList;
itemCount = 0;
isSorted = false;
}
// Constructs a list with the default capacity
public SortableArrayList()
{
this(DEFAULT_CAPACITY);
}
/* Adds item to end of list
pre-contition: itemCount < listItem.length() - 1
post-contition: itemCount == itemCount@pre + 1
item added to end of list
*/
public void append(T newItem)
{
listItem[itemCount] = newItem;
itemCount++;
isSorted = false; //List may no longer be sorted
}
/* Return item in given position
If position is out of range, return null
*/
public T getItem(int position)
{
if (0 <= position && position < itemCount)
return listItem[position-1];
else
return null;
}
// Return length of list
public int getLength()
{
return itemCount;
}
// Sort list
public void sort()
{
sortSublist(0,itemCount-1);
System.out.println("\n sort is working\n");
}
// Sort sublist from lowIndex to highIndex
abstract protected void sortSublist(int lowIndex, int highIndex);
/*
Returns the position of the item with the given value.
If the item is not in the list, returns -1.
*/
public int search(T searchValue)
{
if (isSorted)
{
return binarySearch(searchValue,0,itemCount-1);
}
else
{
return linearSearch(searchValue);
}
}
/*
Searches for the index of the given value using the binary search algorithm
*/
private int binarySearch(T searchValue, int lowIndex, int highIndex)
{
if (highIndex < lowIndex)
{
return -1; // not in list
}
else
{
int midIndex = lowIndex + (highIndex-lowIndex)/2;
if (listItem[midIndex].equals(searchValue))
{
return midIndex; //found it -- position is one more than index
}
else if (listItem[midIndex].compareTo(searchValue) > 0)
{
// searchValue comes before midIndex in array
return binarySearch(searchValue,lowIndex,midIndex-1);
}
else
{
// listItem[midIndex] comes after midIndex in array
return binarySearch(searchValue,midIndex+1,highIndex);
}
}
}
// Searches for the index of the given value using linear search
private int linearSearch(T searchValue)
{
int index = itemCount-1;
while (index >= 0 && !listItem[index].equals(searchValue))
{
index--;
}
return index;
}
// Returns a string of the items in the list --
public String toString()
{
StringBuilder returnStringBuilder = new StringBuilder();
for (int i = 0; i < itemCount; i++)
{
returnStringBuilder.append(listItem[i].toString() + "\n");
}
return returnStringBuilder.toString();
}
}
I believe that my problem is related to these three files so I wont post the others. If no one finds anything wrong with these three then Ill post the others. There is a seperate driver that I use for sorting the list of names. I need to be able to run that driver and have it sort the txt list of names and run this driver to sort the array of integers. Both drivers need to use the other three files. It looks like the if statement in sortableArrayListWithSelectionSortII.java is not running and neither is the for statement so Im pretty sure the problem is with how my driver talks to the selection sort. I've spent a lot of time on this so any help is very much appreciated
