java, how to remove dupliates only once from a sorted array?

Posted on 2007-11-18
Last Modified: 2013-11-23
I am stuck with the program, the program should remove the duplicates only once. for example,
if is there, 11123455533
the result should be, 11234553
what should i do?


   import java.util.*;

   import java.lang.*;

   import java.util.HashSet;

   import java.util.Set;

    class ArrayIns


      private double[] a;  // array of values

      private int nIns;

       public ArrayIns(int size)


         a = new double[size]; // create a space for the array



       public void insert(double value)


         a[nIns] = value;



       public void insertionSort()


         int in, out;

         for(out=1; out<nIns; out++) // out is dividing line


            double 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 right,


            // go left one position


            a[in] = temp; // insert marked item


      } // end for

       public String toString()


         StringBuffer temp = new StringBuffer();

         for(double e : a)

            temp.append(e + "");


         return temp.toString();



   ////////////------------------main calss --------------//////////////

 class a3


       public static void main(String[] args)


         Set uniques = new HashSet();

         Set dups = new HashSet();

         ArrayIns a[] = new ArrayIns[3];

         //int[] arr = new int[a];

         for(int i = 0;  i< 5; i++ )


            Scanner s = new Scanner(;

            System.out.println(" Enter the Integers:  ");

            a[i] = s.nextInt();




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Question by:hadaram49
  • 2

Accepted Solution

ysnky earned 250 total points
ID: 20310646
a dirty code, you can optimise
  private static ArrayList doublicateOnce(int[] ary) {


	  ArrayList list = new ArrayList();

	  if (ary.length > 0) {


		  int active = ary[0];

		  int count  = 0;

		  list.add(new Integer(ary[0]));


		  for (int i=1; i<ary.length; i++) {


			  if (active != ary[i] || count > 0) {


				  if (active != ary[i])

					  count = 0;


				  list.add(new Integer(ary[i]));

			  } else {





			  active = ary[i];




	  return list;


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LVL 11

Expert Comment

ID: 20331092
As ysnky points out, it's easy enough to clean up the array after it has been sorted. If your assignment requires that you modify the sort algorithm itself to eliminate exactly one of a set with population greater than 1, the challenge is quite different.

I think I see where you're going with the two HashSets. It would be easy to track the two sets of information you need with this architecture, but you must reconsider where you need to do this. However, just tracking these items doesn't solve the entire problem: you still have to find a way to get rid of the unwanted elements. Arrays don't cooperate when you want to delete an element, so you'll have to consider alternatives or workarounds that are feasible within the constraints of your assignment. Maybe you can use ysnky's approach or another method more or less like it. Maybe you can use other data types. Maybe you can be circumspect about how you populate an array.

Best of luck.

Assisted Solution

VBGuru earned 250 total points
ID: 20468399
check out the below solution

public class Test {
      public static void main(String[] args) {
            Test test = new Test();

      private String getParsedString(String stringToParse) {
            Map<Character, Integer> map = new HashMap<Character, Integer>();
            char[] chars = stringToParse.toCharArray();
            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < chars.length; i++) {
                  if (!map.containsKey(chars[i])) {
                        map.put(chars[i], 1);
                  } else if (map.containsKey(chars[i]) && map.get(chars[i]) < 2) {
                        map.put(chars[i], 2);
            return builder.toString();

Expert Comment

ID: 20468409
Please pass the complete content of the file as a string to the method getParsedString to get the output.

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