Default Methods

Lab Java Intermediate 20 points

Create interface Discount with double apply(double price) and a Java 8 default method String label() returning discount. Implement Percent(p) (overrides label to P% off) and Flat(amount) (keeps the default). Read a price and discounts and print each final price and label.

Input

Line 1: price. Line 2: n. Then lines percent P or flat A.

Output

n lines: PRICE (LABEL)

Example

Input

200
3
percent 25
flat 30
flat 500

Output

150.00 (25% off)
170.00 (discount)
0.00 (discount)

Sample input available Sample output available

Editor

Java

Hints

default methods give interfaces a body (Java 8+).

Solution explanation

Default methods let interfaces grow without breaking every class that already implements them.

Show solution

import java.util.Scanner;

interface Discount {
    double apply(double price);

    default String label() {
        return "discount";
    }
}

class Percent implements Discount {
    final int p;
    Percent(int p) { this.p = p; }
    public double apply(double price) { return price * (100 - p) / 100; }
    public String label() { return p + "% off"; }
}

class Flat implements Discount {
    final double amount;
    Flat(double amount) { this.amount = amount; }
    public double apply(double price) { return Math.max(0, price - amount); }
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double price = sc.nextDouble();
        int n = sc.nextInt();
        for (int i = 0; i < n; i++) {
            String kind = sc.next();
            Discount d = kind.equals("percent") ? new Percent(sc.nextInt()) : new Flat(sc.nextDouble());
            System.out.printf("%.2f (%s)%n", d.apply(price), d.label());
        }
    }
}

Output

Answer