Plant Discovery

package ExamPreperationLastExamContests;

import java.util.*;

public class PlantDiscovery {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());
        Map<String, Integer> mapRarity = new HashMap<>();
        Map<String , List<Double>> mapRating= new HashMap<>();
        for (int i = 0; i < n; i++) {
            String input = scanner.nextLine();
            String[]inputArr = input.split("<->");
            String plant = inputArr[0];
            int rarity = Integer.parseInt(inputArr[1]);
            mapRarity.put(plant, rarity);
            mapRating.putIfAbsent(plant, new ArrayList<>());
            mapRating.get(plant).add(0.0);
        }

        String command = scanner.nextLine();
        while (!command.equals("Exhibition")){
            String [] commandArr = command.split(" - ");
            String commandName = commandArr[0];
            if (commandName.contains("Rate:")) {
                String plant = commandName.substring(6);
                double rarity = Double.parseDouble(commandArr[1]);
                if (mapRarity.containsKey(plant) && mapRating.size() >0){
                    if (mapRating.get(plant).get(0) == 0){

                        mapRating.get(plant).clear();
                        mapRating.get(plant).add(rarity);
                    } else {
                        mapRating.get(plant).add(rarity);
                    }
                }else {
                    System.out.println("error");
                }
            } else if (commandName.contains("Update")) {
                String plant = commandName.substring(8);
                int newRarity = Integer.parseInt(commandArr[1]);
                if (mapRarity.containsKey(plant)){
                    mapRarity.put(plant,newRarity);
                }else {
                    System.out.println("error");
                }

            } else {
                String plant = commandName.substring(7);

                if (mapRarity.containsKey(plant)){

                        mapRating.get(plant).clear();

                }else {
                    System.out.println("error");
                }

            }


            command = scanner.nextLine();
        }
        System.out.println("Plants for the exhibition:");
        mapRarity.entrySet().stream().sorted(Map.Entry.<String, Integer>comparingByValue()
                .thenComparingDouble(x -> mapRating.get(x.getKey()).stream()
                        .mapToDouble(Double::doubleValue)
                        .average().orElse(0.0))
                .reversed())

                .forEach(entry -> System.out.printf("- %s; Rarity: %d; Rating: %.2f%n",
                        entry.getKey(), entry.getValue(),
                        mapRating.get(entry.getKey()).stream()
                                .mapToDouble(Double::doubleValue)
                                .average().orElse(0.0)));
    }
}