Все как в примере, что не так?
package com.javarush.task.task22.task2207;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.List;
import java.util.StringTokenizer;
/*
Обращенные слова
*/
public class Solution {
public static List<Pair> result = new LinkedList<>();
public static void main(String[] args) {
StringBuilder s = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(new BufferedReader(new InputStreamReader(System.in)).readLine()), "UTF8"));
String nextString;
while ((nextString = br.readLine()) != null) {
if (s.length() == 0)
s.append(nextString.substring(1, nextString.length()));
else if (nextString.length() != 0)
s.append(" " + nextString);
}
} catch (IOException e) {
e.printStackTrace();
}
// System.out.println(s);
String[] ss = s.toString().split(" ");
for (int i = 0; i < ss.length; i++)
for (int j = i + 1; j < ss.length; j++) {
if (ss[i].length() > 0 & ss[i].equals(new StringBuilder(ss[j]).reverse().toString())) {
Pair pair = new Pair(ss[i], ss[j]);
// if (!result.contains(pair)) {
ss[i] = "";
ss[j] = "";
result.add(pair);
// }
}
}
for (Pair pair : result)
System.out.println(pair);
}
public static class Pair {
String first;
String second;
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Pair pair = (Pair) o;
if (first != null ? !first.equals(pair.first) : pair.first != null) return false;
return second != null ? second.equals(pair.second) : pair.second == null;
}
@Override
public int hashCode() {
int result = first != null ? first.hashCode() : 0;
result = 31 * result + (second != null ? second.hashCode() : 0);
return result;
}
@Override
public String toString() {
return first == null && second == null ? "" :
first == null && second != null ? second :
second == null && first != null ? first :
first.compareTo(second) < 0 ? first + " " + second : second + " " + first;
}
public Pair(String first, String second) {
this.first = first;
this.second = second;
}
public Pair() {
}
}
}