в чем проблема?
package com.javarush.task.task22.task2207;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.io.IOException;
/*
Обращенные слова
*/
public class Solution {
public static List<Pair> result = new LinkedList<>();
public static void main(String[] args) throws IOException{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String filename = br.readLine();
br.close();
FileReader fr = new FileReader(filename);
BufferedReader br1 = new BufferedReader(fr);
String ss = "";
StringBuilder sb = new StringBuilder();
while((ss = br1.readLine()) != null){
sb.append(ss);
sb.append(" ");
}
String text = sb.toString();
String[] s = text.split(" ");
for(int i = 0;i<s.length;i++){
for(int j = i+1; j<s.length;j++){
StringBuilder b = new StringBuilder(s[j]);
if(s[i].equals(s[j]) | s[i].equals(b.reverse().toString())){
Pair p = new Pair();
p.first = s[i];
p.second = s[j];
result.add(p);
}
}
}
for(Pair i : result){
System.out.println(i.first+" "+i.second);
}
}
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 :
second == null ? first :
first.compareTo(second) < 0 ? first + " " + second : second + " " + first;
}
}
}