Какие есть еще варианты проверить? Находит все верно, как в образце задачи.
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.*;
/*
Обращенные слова
*/
public class Solution {
public static List<Pair> result = new LinkedList<>();
public static void main(String[] args) throws IOException {
String path;
ArrayList<String> arr = new ArrayList<>();
try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
path = br.readLine();
}
try (BufferedReader fileReader = new BufferedReader(new FileReader(path));) {
while (fileReader.ready()) {
arr.addAll(Arrays.asList(fileReader.readLine().split(" ")));
}
}
for (int i = 0; i < arr.size(); i++) {
StringBuilder sb = new StringBuilder(arr.get(i));
sb.reverse();
if (arr.contains(sb.toString())) {
Pair pair = new Pair();
pair.first = arr.get(i);
pair.second = sb.toString();
arr.remove(i);
if (!(result.contains(pair)))
result.add(pair);
}
}
result.forEach(System.out::println);
}
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;
}
}
}