01. KAT

package Advanced;

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

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        ArrayDeque<Long> licensePlatesQueue = Arrays.stream(scanner.nextLine().split(", "))
                .map(Long::parseLong)
                .collect(Collectors.toCollection(ArrayDeque::new));

        ArrayDeque<Long> carsStack = new ArrayDeque<>();

        Arrays.stream(scanner.nextLine().split(", "))
                .map(Long::parseLong)
                .forEach(carsStack::push);

        int daysCount = 0;
        long registeredCarsCount = 0;

        while (!licensePlatesQueue.isEmpty() && !carsStack.isEmpty()) {
            long currentPlatesCount = licensePlatesQueue.poll();
            long currentCarsCount = carsStack.pop();
            daysCount++;
            long remainingPlates;
            long remainingCars;
            if (currentPlatesCount / 2 < currentCarsCount) {
                registeredCarsCount += currentPlatesCount / 2;
                remainingCars = currentCarsCount - currentPlatesCount / 2;
                carsStack.push(remainingCars);
            } else if (currentPlatesCount / 2 > currentCarsCount) {
                remainingPlates = currentPlatesCount - currentCarsCount * 2;
                licensePlatesQueue.offer(remainingPlates);
                registeredCarsCount += currentCarsCount;
            } else {
                registeredCarsCount += currentPlatesCount / 2;
            }
        }

        System.out.printf("%d cars were registered for %d days!\n", registeredCarsCount, daysCount);

        if (!licensePlatesQueue.isEmpty()) {
            long platesRemain = 0;
            while (!licensePlatesQueue.isEmpty()) {
                platesRemain += licensePlatesQueue.poll();
            }
            System.out.printf("%d license plates remain!", platesRemain);
        } else if (!carsStack.isEmpty()) {
            long unregisteredCars = 0;
            while (!carsStack.isEmpty()) {
                unregisteredCars += carsStack.pop();
            }
            System.out.printf("%d cars remain without license plates!", unregisteredCars);
        } else {
            System.out.print("Good job! There is no queue in front of the KAT!");
        }
    }

}