Student Records

Lab Java Advanced 30 points

Read students id name mark1 mark2 mark3. Print a report sorted by average descending, then id: id name average grade (A ≥ 85, B ≥ 70, C ≥ 50, else F), then the class average and the number of students per grade in the order A B C F.

Input

n, then n lines.

Output

n report lines, then two summary lines.

Example

Input

4
3 cy 90 80 100
1 ann 70 75 65
2 bob 40 55 50
4 dan 90 90 90

Output

3 cy 90.0 A
4 dan 90.0 A
1 ann 70.0 B
2 bob 48.3 F
class average 74.6
A=2 B=1 C=0 F=1

Sample input available Sample output available

Editor

Java

Hints

Pre-fill a LinkedHashMap with A B C F so the summary keeps that order.

Solution explanation

Classes, collections, comparators and formatting together make a complete small report generator.

Show solution

import java.util.ArrayList;
import java.util.Comparator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

class Student {
    final int id;
    final String name;
    final double average;

    Student(int id, String name, double average) {
        this.id = id;
        this.name = name;
        this.average = average;
    }

    String grade() {
        return average >= 85 ? "A" : average >= 70 ? "B" : average >= 50 ? "C" : "F";
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        List<Student> students = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            int id = sc.nextInt();
            String name = sc.next();
            double avg = (sc.nextInt() + sc.nextInt() + sc.nextInt()) / 3.0;
            students.add(new Student(id, name, avg));
        }
        students.sort(Comparator.comparingDouble((Student s) -> -s.average).thenComparingInt(s -> s.id));
        Map<String, Integer> perGrade = new LinkedHashMap<>();
        for (String g : new String[]{"A", "B", "C", "F"}) perGrade.put(g, 0);
        double total = 0;
        for (Student s : students) {
            System.out.printf("%d %s %.1f %s%n", s.id, s.name, s.average, s.grade());
            perGrade.merge(s.grade(), 1, Integer::sum);
            total += s.average;
        }
        System.out.printf("class average %.1f%n", total / n);
        StringBuilder sb = new StringBuilder();
        perGrade.forEach((g, c) -> sb.append(sb.length() > 0 ? " " : "").append(g).append('=').append(c));
        System.out.println(sb);
    }
}

Output

Answer