[NP] Subtitles

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.time.LocalTime;

import java.util.Scanner;
class Element {
    private int id;
    private String time;
    private String reply;

    public Element(int id, String time, String reply) {
        this.id = id;
        this.time = time;
        this.reply = reply;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

public long getNanoSeconds(String time) {
    String[] parts = time.split(",");
    LocalTime localTime = LocalTime.parse(parts[0]); // "HH:mm:ss"
    long baseNanos = localTime.toNanoOfDay(); // total nanos up to this time
    long extraNanos = Long.parseLong(parts[1]); // extra nanos from input
    return baseNanos + extraNanos;
}

public void changeTime(int shift) {
    String[] times = time.replace(" --> ", " ").split("\\s+");

    long nanoStart = getNanoSeconds(times[0]) + shift;
    long nanoEnd = getNanoSeconds(times[1]) + shift;

    String formattedStart = formatWithLast3Nanos(nanoStart,shift);
    String formattedEnd = formatWithLast3Nanos(nanoEnd,shift);

    setTime(formattedStart + " --> " + formattedEnd);
}

private String formatWithLast3Nanos(long nanos, int shift) {
    LocalTime time = LocalTime.ofNanoOfDay(nanos);
    int nano = time.getNano(); // full nanos
    int last3 = nano % 1000;   // last 3 digits
    if(shift>0 && last3-shift<0)
        return String.format("%02d:%02d:%02d,%03d",
        time.getHour(), time.getMinute(), time.getSecond()+1, last3);
    else if(shift<0 && last3+shift>1000)
        return String.format("%02d:%02d:%02d,%03d",
        time.getHour(), time.getMinute(), time.getSecond()-1, last3);
    else
        return String.format("%02d:%02d:%02d,%03d",
        time.getHour(), time.getMinute(), time.getSecond(), last3);
}

    @Override
    public String toString() {
        return String.format("%d\n%s\n%s\n",id,time,reply);
    }
}

public class SubtitlesTest {
    public static void main(String[] args) {
        Subtitles subtitles = new Subtitles();
        int n = subtitles.loadSubtitles(System.in);
        System.out.println("+++++ ORIGINIAL SUBTITLES +++++");
        subtitles.print();
        int shift = n * 37;
        shift = (shift % 2 == 1) ? -shift : shift;
        System.out.println(String.format("SHIFT FOR %d ms", shift));
        subtitles.shift(shift);
        System.out.println("+++++ SHIFTED SUBTITLES +++++");
        subtitles.print();
    }
}

 class Subtitles {
    private List<Element> elements;

    public Subtitles() {
        this.elements = new ArrayList<>();
    }

    public int loadSubtitles(InputStream in) {
        Scanner scanner = new Scanner(in);

        while (scanner.hasNextLine()) {
            String line = scanner.nextLine().trim();
            if (line.isEmpty()) continue;
            int id = Integer.parseInt(line);
            String time = scanner.nextLine().trim();
            String text = scanner.nextLine().trim();
            while (scanner.hasNextLine()) {
                String nextLine = scanner.nextLine().trim();
                if (nextLine.isEmpty()) break;
                text += "\n" + nextLine;
            }
            elements.add(new Element(id, time, text));
        }
        return elements.size();
    }

    public void print() {
        StringBuilder sb= new StringBuilder();
        for(Element e : elements){
            sb.append(e.toString());
            if(e.equals(elements.get(elements.size()-1)))
                break;
            sb.append("\n");
        }

        System.out.println(sb.toString());
    }

    public void shift(int shift) {
  for(Element e: elements)
        e.changeTime(shift);
    }
}