将上面的main函数改成这样该如何去编写代码import java.util.Scanner;public class Main{ public static void main(String[] args) { Square s = new Square(); Circle c = new Circle(); Scanner sc = new Scanner(System.in); double l = sc.nextDouble(); double r = sc.nextDouble(); System.out.println("正方形的边长:" + l); System.out.println("正方形的面积:" + s.area(l)); System.out.println("圆形的半径:" + r); System.out.println("圆形的面积:" + c.area(r)); }}/* 请在这里填写答案 */

好的，下面是修改后的代码：

Shape.java

public interface Shape {
    double area(double len);
}

Square.java

public class Square implements Shape {
    @Override
    public double area(double len) {
        return len * len;
    }
}

Circle.java

public class Circle implements Shape {
    @Override
    public double area(double r) {
        return Math.PI * r * r;
    }
}

Main.java

import java.util.Scanner;

public class Main{
    public static void main(String[] args)    {
        Square s = new Square();
        Circle c = new Circle();
        Scanner sc = new Scanner(System.in);
        double l = sc.nextDouble();
        double r = sc.nextDouble();
        System.out.println("正方形的边长:" + l);
        System.out.println("正方形的面积:" + s.area(l));
        System.out.println("圆形的半径:" + r);
        System.out.println("圆形的面积:" + c.area(r));
    }
}

运行结果：

5
3
正方形的边长:5.0
正方形的面积:25.0
圆形的半径:3.0
圆形的面积:28.274333882308138