Вроде бы все условия выполнены и вывод в файл абсолютно верный
package com.javarush.task.task18.task1820;
import java.io.*;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
/*
Округление чисел
*/
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String input = reader.readLine();
String output = reader.readLine();
ArrayList<String> list = new ArrayList<>();
ArrayList<Double> list2 = new ArrayList<>();
ArrayList<Byte> list3 = new ArrayList<>();
try (BufferedReader bufferedReader = new BufferedReader(new FileReader(input));
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(output))) {
String line = bufferedReader.readLine();
String[] words = line.split(" ");
list.addAll(Arrays.asList(words));
for (String string : list) list2.add(Double.parseDouble(string));
for (double d : list2) {
byte finish = (byte) Math.round(d);
list3.add(finish);
}
for (Byte name : list3)
{
String str = Byte.toString(name);
bufferedWriter.write(str + " ");
}
}
}
}
/*
C:\Users\ilyac\Desktop\123.txt*/