Ребята гляньте глазом и ткните носом.. :)
package com.javarush.task.pro.task05.task0508;
import java.util.Scanner;
public class Solution {
public static String[] strings;
public static void main(String[] args) {
Scanner console = new Scanner(System.in);
strings = new String[6];
for (int i = 0; i < strings.length; i++) {
String text = console.nextLine();
strings[i] = text;
}
String currentString;
for (int i = 0; i < strings.length; i++) {
int flags = 0;
currentString = strings[i];
if (currentString == null) {
continue;
}
for (int j = 0; j < strings.length; j++) {
if (currentString.equals(strings[j])) {
flags++;
if (flags == 2) {
strings[i] = null;
strings[j] = null;
}
}
}
}
for (int i = 0; i < strings.length; i++) {
System.out.print(strings[i] + ", ");
}
}
}