I created the program; but, having issues during execution. It is eleminating th

Question

I created the program; but, having issues during execution. It is eleminating the duplicates; but, placing "0" in their place. The size of the array should decrease after dups or detected and eleminated. However, it is not working properly, and I am not sure what is the problem? Please kindly check the bolded part of the program below:

----------------------------------------------------------

Project:

3.3 To the insertSort.java program (Listing 3.3), add a method called noDups() that removes duplicates from a previously sorted array without disrupting the order. (You can use the insertionSort() method to sort the data, or you can simply use main() to insert the data in sorted order.) One can imagine schemes in which all the items from the place where a duplicate was discovered to the end of the array would be shifted down one space every time a duplicate was discovered, but this would lead to slow O(N2) time, at least when there were a lot of duplicates. In your algorithm, make sure no item is moved more than once, no matter how many duplicates there are. This will give you an algorithm with O(N) time.

-------------------------------------------------------------------

// insertSort.java
// demonstrates insertion sort
// to run this program: C>java InsertSortApp
//--------------------------------------------------------------
class ArrayIns
{
private long[] a; // ref to array a
private int nElems; // number of data items
//--------------------------------------------------------------
public ArrayIns(int max) // constructor
{
a = new long[max]; // create the array
nElems = 0; // no items yet
}
//--------------------------------------------------------------

//=====================================
public void noDups(ArrayIns b)
{
//function call
b.insertionSort();
//variable declaration
int num = b.nElems;
int maxSize = 100;
//object creation and calling constructor method with the parameter maxSize
ArrayIns arrNew;
arrNew = new ArrayIns(maxSize);
for(int i=1; i<nElems; i++)
{
       if(i > 0)
       {
               arrNew.insert(b.a[i]);
               i++;
       }
       else
       {
               if(b.a[i-1]==b.a[i]&&b.a[i]==b.a[i+1])
               {
                   b.nElems--;
                   i++;
               }
               else if (b.a[i]!=b.a[i+1]&&b.a[i]==b.a[i-1])
               {
                   b.nElems--;
                   i++;
               }
               else
               {
                   arrNew.insert(b.a[i]);
                   i++;
               }
       }
}
   b.a = arrNew.a;
}

//=========================================
//--------------------------------------------------------------
public void insert(long value) // put element into array
{
a[nElems] = value; // insert it
nElems++; // increment size
}
//--------------------------------------------------------------
public void display() // displays array contents
{
for(int j=0; j<nElems; j++) // for each element,
System.out.print(a[j] + " "); // display it
System.out.println("");
}
//--------------------------------------------------------------
public void insertionSort()
{
int in, out;
for(out=1; out<nElems; out++) // out is dividing line
{
long temp = a[out]; // remove marked item
in = out; // start shifts at out
while(in>0 && a[in-1] >= temp) // until one is smaller,
{
a[in] = a[in-1]; // shift item to right
--in; // go left one position
}
a[in] = temp; // insert marked item
} // end for
} // end insertionSort()
//--------------------------------------------------------------
} // end class ArrayIns
////////////////////////////////////////////////////////////////
class InsertSortApp
{
public static void main(String[] args)
{
int maxSize = 100; // array size
ArrayIns arr; // reference to array
arr = new ArrayIns(maxSize); // create the array
arr.insert(77); // insert 10 items
arr.insert(11);
arr.insert(55);
arr.insert(55);
arr.insert(22);
arr.insert(88);
arr.insert(77);
arr.insert(00);
arr.insert(66);
arr.insert(33);
arr.insert(00);
arr.insert(88);
arr.insert(11);
arr.insert(00);
arr.insert(66);
arr.insert(22);
arr.display(); // display items
arr.insertionSort(); // insertion-sort them
arr.display(); // display them again

//======================================

System.out.println("After calling Dups function");
arr.noDups(arr);
arr.display();

//==============================================
} // end main()
} // end class InsertSortApp

Explanation / Answer

why cant you implement like this.......

package com.java2novice.treeset;

import java.util.Arrays;

import java.util.List;

import java.util.TreeSet;

public class MyArrayDuplicates {

    public static void main(String a[]){

        String[] strArr = {"one","two","three","four","four","five"};

        //convert string array to list

        List<String> tmpList = Arrays.asList(strArr);

        //create a treeset with the list, which eliminates duplicates

        TreeSet<String> unique = new TreeSet<String>(tmpList);

        System.out.println(unique);

    }

}

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