/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Integer[] intArray = new Integer[] { 0, 1 , 0 , 2 , 3 , 3 , 5 , 6 , -4 ,6 };
 
		LinkedHashSet<Integer> set = new LinkedHashSet<>();
		HashSet<Integer> alreadyPresent = new HashSet<>();
		for (Integer i : intArray) {
		  if (!set.add(i)) {
		    alreadyPresent.add(i);
		  }
		}
		set.removeAll(alreadyPresent);
 
		ArrayList<Integer> list = new ArrayList<>(set);
 
		System.out.println(list);
	}
}

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