java语言程序设计基础篇第十版第十三章练习答案.docxVIP

01public class Exercise13_01 {public static void main(String[] args) {TriangleNew triangle = new TriangleNew(1, 1.5, 1);triangle.setColor(yellow);triangle.setFilled(true);System.out.println(triangle);System.out.println(The area is + triangle.getArea());System.out.println(The perimeter is + triangle.getPerimeter());System.out.println(triangle); }}classTriangleNew extends GeometricObject {private double side1 = 1.0, side2 = 1.0, side3 = 1.0; /** Constructor */publicTriangleNew() { } /** Constructor */publicTriangleNew(double side1, double side2, double side3) { this.side1 = side1; this.side2 = side2; this.side3 = side3; } /** Implement the abstract method findArea in GeometricObject */public double getArea() {double s = (side1 + side2 + side3) / 2;returnMath.sqrt(s * (s - side1) * (s - side2) * (s - side3)); } /** Implement the abstract method findCircumference in * GeometricObject **/public double getPerimeter() {return side1 + side2 + side3; } @Overridepublic String toString() { // Implement it to return the three sidesreturn TriangleNew: side1 = + side1 + side2 = + side2 + side3 = + side3; }}02importjava.util.ArrayList;public class Exercise13_02 {public static void main(String[] args) {ArrayListNumber list = new ArrayListNumber();list.add(14);list.add(24);list.add(4);list.add(42);list.add(5);shuffle(list);for (inti = 0; i list.size(); i++) System.out.print(list.get(i) + ); }public static void shuffle(ArrayListNumber list) {for (inti = 0; i list.size() - 1; i++) {int index = (int)(Math.random() * list.size()); Number temp = list.get(i);list.set(i, list.get(index));list.set(index, temp); } }}03importjava.util.ArrayList;public class Exercise13_03 {public static void main(String[] args) {ArrayListNumber list = new ArrayListNumber();list.add(14);list.add(24);list.add(4);list.add(42);list.add(5);sort(list);for (inti = 0; i list.size(); i++) System.out.print(list.get(i) + ); }public static void sort(ArrayListNumber lis