題解 | 根據(jù)周長(zhǎng)求面積
根據(jù)周長(zhǎng)求面積
http://fangfengwang8.cn/practice/f67cf4ac46dc45769aea8d94e0e2f6bd
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); while (scanner.hasNextDouble()) { double s = scanner.nextDouble(); // Circle和Square是需要你定義的類(lèi) System.out.println(String.format("%.3f",new Circle(s).getArea())); System.out.println(String.format("%.3f", new Square(s).getArea())); } } } class Shape { private double s; // 周長(zhǎng) public Shape(double s) { this.s = s; } public double getS() { return s; } } interface Area { double getArea(); // 面積 } // 圓形 class Circle extends Shape implements Area { //write your code here...... public Circle(double s){ super(s); } public double getArea(){ double r = super.getS() / (2 * Math.PI); return Math.PI * r * r; } } // 方形 class Square extends Shape implements Area { //write your code here...... public Square(double s){ super(s); } public double getArea(){ double len = super.getS() / 4.0; return len * len; } }