Student Academy [Mimi]

import java.util.*;

public class _07_StudentAcademy_v_2 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());

        Map<String, List<Double>> map = new LinkedHashMap<>();

        for (int i = 0; i < n; i ++) {
            String name = scanner.nextLine();
            double grade = Double.parseDouble(scanner.nextLine());

            map.putIfAbsent(name, new ArrayList<>());
            map.get(name).add(grade);
        }

        Map<String, Double> avg = new LinkedHashMap<>();

        for (String name : map.keySet()) {
            double sum = 0;
            int size = map.get(name).size();
            for (int i = 0; i < size; i++) {
                sum += map.get(name).get(i);
            }
            double average = sum / size;
            if (average >= 4.5) {
                avg.put(name, average);
            }
        }

        avg.entrySet()
                .stream()
                .sorted(Map.Entry.<String, Double>comparingByValue().reversed())
                .forEach(kvp -> System.out.printf("%s -> %.2f%n", kvp.getKey(), kvp.getValue()));


    }
}