//最大图形的面积public class ShapeTest {    public static void main(String[] args) {        Shape[] shapes = new Shape[4];        shapes[0] = new Square(1);        shapes[1] = new Square(2);        shapes[2] = new Circle(1);        shapes[3] = new Circle(2);        maxArea(shapes);    }    public static void maxArea(Shape[] Shapes){        double max = Shapes[0].area();        int maxIndex = 0;        for(int i=1;i<Shapes.length;i++){            double area = Shapes[i].area();            if(area>max){                max=area;                maxIndex=i;            }        }        System.out.println("最大面积为:"+max+"，所在下标为:"+maxIndex);    }    }                    abstract class Shape{        protected double c;        public abstract double area();    }                class Square extends Shape{        public Square(double c){            this.c=c;        }        public double area(){            return 0.0625*c*c; //0.0796        }    }             class Circle extends Shape{        public Circle(double c){        this.c=c;    }        public double area(){        return 0.0796*c*c;    }}