完成W5作业

Circle.java

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+public class Circle extends Shape {
+    private double radius;
+    
+    public Circle(double radius) {
+        this.radius = radius;
+    }
+    
+    @Override
+    public double getArea() {
+        return Math.PI * radius * radius;
+    }
+    
+    @Override
+    public void draw() {
+        System.out.println("Drawing a circle with radius " + radius);
+    }
+}

Main.java

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+public class Main {
+    public static void main(String[] args) {
+        Shape circle = new Circle(5);
+        Shape rectangle = new Rectangle(4, 6);
+        Shape triangle = new Triangle(3, 8);
+        
+        System.out.println("Circle:");
+        ShapeUtil.printArea(circle);
+        ShapeUtil.drawShape(circle);
+        
+        System.out.println("Rectangle:");
+        ShapeUtil.printArea(rectangle);
+        ShapeUtil.drawShape(rectangle);
+        
+        System.out.println("Triangle:");
+        ShapeUtil.printArea(triangle);
+        ShapeUtil.drawShape(triangle);
+    }
+}

Rectangle.java

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+public class Rectangle extends Shape {
+    private double width;
+    private double height;
+    
+    public Rectangle(double width, double height) {
+        this.width = width;
+        this.height = height;
+    }
+    
+    @Override
+    public double getArea() {
+        return width * height;
+    }
+    
+    @Override
+    public void draw() {
+        System.out.println("Drawing a rectangle with width " + width + " and height " + height);
+    }
+}

Shape.java

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+public abstract class Shape {
+    public abstract double getArea();
+    public abstract void draw();
+}

ShapeUtil.java

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+public class ShapeUtil {
+    public static void printArea(Shape shape) {
+        System.out.println("Area: " + shape.getArea());
+    }
+    
+    public static void drawShape(Shape s) {
+        s.draw();
+    }
+}

Triangle.java

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+public class Triangle extends Shape {
+    private double base;
+    private double height;
+    
+    public Triangle(double base, double height) {
+        this.base = base;
+        this.height = height;
+    }
+    
+    @Override
+    public double getArea() {
+        return 0.5 * base * height;
+    }
+    
+    @Override
+    public void draw() {
+        System.out.println("Drawing a triangle with base " + base + " and height " + height);
+    }
+}