Trojan Invasion [Mimi][JA]

import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Scanner;
import java.util.stream.Collectors;

public class _01_TrojanInvasion {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int waves = Integer.parseInt(sc.nextLine());
        //Queue:
        ArrayDeque<Integer> defenders =
                Arrays.stream(sc.nextLine()
                        .split("\\s+"))
                        .map(Integer::parseInt)
                        .collect(Collectors.toCollection(ArrayDeque::new));

        //Stack:
        ArrayDeque<Integer> attackers = new ArrayDeque<>();
        for (int i = 1; i <= waves && !defenders.isEmpty(); i++) {
            Arrays.stream(sc.nextLine()
                    .split("\\s+"))
                    .map(Integer::parseInt)
                    .forEach(attackers::push);

            if (i % 3 == 0){
              int extraDef = Integer.parseInt(sc.nextLine());
              defenders.offer(extraDef);
            }

            while (!attackers.isEmpty() && !defenders.isEmpty()){

                int attack = attackers.pop();
                int defense = defenders.poll();

                if (attack > defense){
                    attack -= defense;
                    attackers.push(attack);
                }else if(defense > attack){
                    defense -= attack;
                    defenders.addFirst(defense);
                }
            }
        }


        if (defenders.isEmpty()){
            System.out.println("The Trojans successfully destroyed the Spartan defense.");
            System.out.printf("Warriors left: %s%n",
                    String.join(", ", attackers.toString().replaceAll("[\\[\\]]", "")));

        } else {
            System.out.println("The Spartans successfully repulsed the Trojan attack.");
            System.out.printf("Plates left: %s%n",
                    String.join(", ", defenders.toString().replaceAll("[\\[\\]]", "")));
        }
    }
}