HackerRank-Solutions/General Programming/Object-oriented Programming/Inheritance/Solution.java

//     Author: Rodney Shaghoulian
//     Github: github.com/RodneyShag
// HackerRank: hackerrank.com/RodneyShag

import java.util.*;

class Person {
    protected String firstName;
    protected String lastName;
    protected int idNumber;
    
    // Constructor
    Person(String firstName, String lastName, int identification) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.idNumber = identification;
    }
    
    // Print person data
    public void printPerson() {
         System.out.println(
                "Name: " + lastName + ", " + firstName 
            +   "\nID: " + idNumber); 
    }
}

class Student extends Person {
    private int[] testScores;

    /*  
    *   Class Constructor
    *   
    *   @param firstName - A string denoting the Person's first name.
    *   @param lastName - A string denoting the Person's last name.
    *   @param id - An integer denoting the Person's ID number.
    *   @param scores - An array of integers denoting the Person's test scores.
    */
    public Student(String firstName, String lastName, int id, int [] scores) {
        super(firstName, lastName, id);
        testScores = scores;
    }

    /*  
    *   Method Name: calculate
    *   @return A character denoting the grade.
    */
    public char calculate() {
        double average = 0;
        for (int score : testScores) {
            average += score;
        }
        average /= testScores.length;
        
        if  (average >= 90) {
            return 'O';
        } else if (average >= 80) {
            return 'E';
        } else if (average >= 70) {
            return 'A';
        } else if (average >= 55) {
            return 'P';
        } else if (average >= 40) {
            return 'D';
        } else {
            return 'T';
        }
    }
}

class Solution {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String firstName = scan.next();
        String lastName = scan.next();
        int id = scan.nextInt();
        int numScores = scan.nextInt();
        int[] testScores = new int[numScores];
        for (int i = 0; i < numScores; i++) {
            testScores[i] = scan.nextInt();
        }
        scan.close();
        
        Student s = new Student(firstName, lastName, id, testScores);
        s.printPerson();
        System.out.println("Grade: " + s.calculate());
    }
}