java语言程序设计基础篇第十版第十三章练习答案.docx

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); class TriangleNew extends GeometricObject private double side1 = 1.0, side2 = 1.0, side3 = 1.0; /* Constructor */ public TriangleNew() /* Constructor */ public TriangleNew(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; return Math.sqrt(s * (s - side1) * (s - side2) * (s - side3); /* Implement the abstract method findCircumference in * GeometricObject */ public double getPerimeter() return side1 + side2 + side3; Override public String toString() / Implement it to return the three sides return TriangleNew: side1 = + side1 + side2 = + side2 + side3 = + side3; 02import java.util.ArrayList;public class Exercise13_02 public static void main(String args) ArrayList list = new ArrayList(); list.add(14); list.add(24); list.add(4); list.add(42); list.add(5); shuffle(list); for (int i = 0; i list.size(); i+) System.out.print(list.get(i) + ); public static void shuffle(ArrayList list) for (int i = 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); 03import java.util.ArrayList;public class Exercise13_03 public static void main(String args) ArrayList list = new ArrayList(); list.add(14); list.add(24); list.add(4); list.add(42); list.add(5); sort(list); for (int i = 0; i list.size(); i+) System.out.print(list.get(i) + ); public static void sort(ArrayList list) for (int i = 0; i list.size() - 1; i+) / Find the minimum in the listi.list.length-1 Number currentMin = list.get(i); int currentMinIndex = i; for (int j = i + 1; j list.get(j).doubleValue() currentMin = list.get(j); currentMinIndex = j; / Swap list.get(i) with list.get(currentMinIndex) if necessary; if (currentMinIndex != i) list.set(currentMinIndex, list.get(i); list.set(i, currentMin); 04import java.util.*;public class Exercise13_04 static MyCalendar calendar = new MyCalendar(); public static void main(String args) int month = calendar.get(MyCalendar.MONTH) + 1; int year = calendar.get(MyCalendar.YEAR); if (args.length 2) System.out.println(Usage java Exercise13_04 month year); else if (args.length = 2) /use user-defined month and year year = Integer.parseInt(args1); month = Integer.parseInt(args0); calendar.set(Calendar.YEAR, year); calendar.set(Calendar.MONTH, month - 1); else if (args.length = 1) /use user-defined month for the current year month = Integer.parseInt(args0); calendar.set(Calendar.MONTH, month-1); /set date to the first day in a month calendar.set(Calendar.DATE, 1); /print calendar for the month printMonth(year, month); static void printMonth(int year, int month) /get start day of the week for the first date in the month int startDay = getStartDay(); /get number of days in the month int numOfDaysInMonth = calendar.daysInMonth(); /print headings printMonthTitle(year, month); /print body printMonthBody(startDay, numOfDaysInMonth); static int getStartDay() return calendar.get(Calendar.DAY_OF_WEEK); static void printMonthBody(int startDay, int numOfDaysInMonth) /print padding space before the first day of the month int i = 0; for (i = 0; i startDay-1; i+) System.out.print( ); for (i = 1; i = numOfDaysInMonth; i+) if (i 10) System.out.print( +i); else System.out.print( +i); if (i + startDay - 1) % 7 = 0) System.out.println(); System.out.println(); static void printMonthTitle(int year, int month) System.out.println( +calendar.getMonthName()+, +year); System.out.println(-); System.out.println( Sun Mon Tue Wed Thu Fri Sat); 05public class Exercise13_05 / Main method public static void main(String args) / Create two comparable circles Circle1 circle1 = new Circle1(5); Circle1 circle2 = new Circle1(4); / Display the max circle Circle1 circle = (Circle1) GeometricObject1.max(circle1, circle2); System.out.println(The max circles radius is + circle.getRadius(); System.out.println(circle); abstract class GeometricObject1 implements Comparable protected String color; protected double weight; / Default construct protected GeometricObject1() color = white; weight = 1.0; / Construct a geometric object protected GeometricObject1(String color, double weight) this.color = color; this.weight = weight; / Getter method for color public String getColor() return color; / Setter method for color public void setColor(String color) this.color = color; / Getter method for weight public double getWeight() return weight; / Setter method for weight public void setWeight(double weight) this.weight = weight; / Abstract method public abstract double getArea(); / Abstract method public abstract double getPerimeter(); public int compareTo(GeometricObject1 o) if (getArea() 0) return o1; else return o2; / Circle.java: The circle class that extends GeometricObjectclass Circle1 extends GeometricObject1 protected double radius; / Default constructor public Circle1() this(1.0, white, 1.0); / Construct circle with specified radius public Circle1(double radius) super(white, 1.0); this.radius = radius; / Construct a circle with specified radius, weight, and color public Circle1(double radius, String color, double weight) super(color, weight); this.radius = radius; / Getter method for radius public double getRadius() return radius; / Setter method for radius public void setRadius(double radius) this.radius = radius; / Implement the findArea method defined in GeometricObject public double getArea() return radius * radius * Math.PI; / Implement the findPerimeter method defined in GeometricObject public double getPerimeter() return 2 * radius * Math.PI; / Override the equals() method defined in the Object class public boolean equals(Circle1 circle) return this.radius = circle.getRadius(); Override public String toString() return Circle radius = + radius; Override public int compareTo(GeometricObject1 o) if (getRadius() (Circle1) o).getRadius() return 1; else if (getRadius() (Circle1) o).getRadius() return -1; else return 0; 06public class Exercise13_06 / Main method public static void main(String args) / Create two comarable rectangles ComparableCircle circle1 = new ComparableCircle(5); ComparableCircle circle2 = new ComparableCircle(15); / Display the max rect ComparableCircle circle3 = (ComparableCircle)Max.max(circle1, circle2); System.out.println(The max circles radius is + circle3.getRadius(); System.out.println(circle3); class ComparableCircle extends Circle implements Comparable /* Construct a ComparableRectangle with specified properties */ public ComparableCircle(double radius) super(radius); Override public int compareTo(ComparableCircle o) if (getRadius() o.getRadius() return 1; else if (getRadius() 0) return o1; else return o2; 07public class Exercise13_07 public static void main(String args) GeometricObject objects = new Square(2), new Circle(5), new Square(5), new Rectangle(3, 4), new Square(4.5); for (int i = 0; i objects.length; i+) System.out.println(Area is + objectsi.getArea(); if (objectsi instanceof Colorable) (Colorable)objectsi).howToColor(); interface Colorable void howToColor();class Square extends GeometricObject implements Colorable private double side; public Square(double side) this.side = side; Override public void howToColor() System.out.println(Color all four sides); Override public double getArea() return side * side; Override public double getPerimeter() return 4 * side; 08import java.util.ArrayList;public class Exercise13_08 public static void main(String args) MyStack1 stack = new MyStack1(); stack.push(S1); stack.push(S2); stack.push(S); MyStack1 stack2 = (MyStack1) (stack.clone(); stack2.push(S1); stack2.push(S2); stack2.push(S); System.out.println(stack.getSize(); System.out.println(stack2.getSize(); class MyStack1 implements Cloneable private ArrayList list = new ArrayList(); public boolean isEmpty() return list.isEmpty(); public int getSize() return list.size(); public Object peek() return list.get(getSize() - 1); public Object pop() Object o = list.get(getSize() - 1); list.remove(getSize() - 1); return o; public void push(Object o) list.add(o); /* Override the toString in the Object class */ public String toString() return stack: + list.toString(); public Object clone() try MyStack1 c = (MyStack1) super.clone(); c.list = (ArrayList) this.list.clone(); return c; catch (CloneNotSupportedException ex) return null; 09public class Exercise13_09 public static void main(String args) Circle13_09 obj1 = new Circle13_09(); Circle13_09 obj2 = new Circle13_09(); System.out.println(obj1.equals(obj2); System.out.println(pareTo(obj2); / Circle.java: The circle class that extends GeometricObjectclass Circle13_09 extends GeometricObject implements Comparable private double radius; /* Return radius */ public double getRadius() return radius; /* Set a new radius */ public void setRadius(double radius) this.radius = radius; /* Implement the getArea method defined in GeometricObject */ public double getArea() return radius * radius * Math.PI; /* Implement the getPerimeter method defined in GeometricObject*/ public double getPerimeter() return 2 * radius * Math.PI; Override public String toString() return Circle radius = + radius; Override public int compareTo(Circle13_09 obj) if (this.getArea() obj.getArea() return 1; else if (this.getArea() obj.getArea() return -1; else return 0; public boolean equals(Object obj) return this.radius = (Circle13_09)obj).radius; 10public class Exercise13_10 public static void main(String args) Rectangle13_10 obj1 = new Rectangle13_10(); Rectangle13_10 obj2 = new Rectangle13_10(); System.out.println(obj1.equals(obj2); System.out.println(pareTo(obj2); / Rectangle.java: The Rectangle class that extends GeometricObjectclass Rectangle13_10 extends GeometricObject implements Comparable private double width; private double height; /* Default constructor */ public Rectangle13_10() this(1.0, 1.0); /* Construct a rectangle with width and height */ public Rectangle13_10(double width, double height) this.width = width; this.height = height; /* Return width */ public double getWidth() return width; /* Set a new width */ public void setWidth(double width) this.width = width; /* Return height */ public double getHeight() return height; /* Set a new height */ public void setHeight(double height) this.height = height; /* Implement the getArea method in GeometricObject */ public double getArea() return width*height; /* Implement the getPerimeter method in GeometricObject */ public double getPerimeter() return 2*(width + height); Override public String toString() return Rectangle width = + width + and height = + height; Override public int compareTo(Rectangle13_10 obj) if (this.getArea() obj.getArea() return 1; else if (this.getArea() obj.getArea() return -1; else return 0; public boolean equals(Object obj) return this.getArea() = (Rectangle13_10)obj).getArea(); 11public class Exercise13_11 public static void main(String args) Octagon a1 = new Octagon(5); System.out.println(Area is + a1.getArea(); System.out.println(Perimeter is + a1.getPerimeter(); Octagon a2 = (Octagon)(a1.clone(); System.out.println(Compare the methods + pareTo(a2); class Octagon extends GeometricObject implements Comparable, Cloneable private double side; /* Construct a Octagon with the default side */ public Octagon () / Implement it this.side = 1; /* Construct a Octagon with the specified side */ public Octagon (double side) / Implement it this.side = side; Override /* Implement the abstract method getArea in GeometricObject */ public double getArea() / Implement it return (2 + 4 / Math.sqrt(2) * side * side; Override /* Implement the abstract method getPerimeter in GeometricObject */ public double getPerimeter() / Implement it return 8 * side; Override public int compareTo(Octagon obj) if (this.side obj.side) return 1; else if (this.side = obj.side) return 0; else return -1; Override /* Implement the clone method in the Object class */ public Object clone() / Octagon o = new Octagon();/ o.side = this.side;/ return o;/ / Implement it try return super.clone(); / Automatically perform a shallow copy catch (CloneNotSupportedException ex) return null; 12public class Exercise13_12 public static void main(String args) new Exercise13_12(); public Exercise13_12() GeometricObject a = new Circle(5), new Circle(6), new Rectangle13_12(2, 3), new Rectangle13_12(2, 3); System.out.println(The total area is + sumArea(a); public static double sumArea(GeometricObject a) double sum = 0; for (int i = 0; i a.length; i+) sum += ai.getArea(); return sum; / Rectangle.java: The Rectangle class that extends GeometricObjectclass Rectangle13_12 extends GeometricObject private double width; private double height; /* Construct a rectangle with width and height */ public Rectangle13_12(double width, double height) this.width = width; this.height = height; /*Return width*/ public double getWidth() return width; /*Set a new width*/ public void setWidth(double width) this.width = width; /*Return height*/ public double getHeight() return height; /*Set a new height*/ public void setHeight(double height) this.height = height; /*Implement the getArea method in GeometricObject*/ public double getArea() return width*height; /*Implement the getPerimeter method in GeometricObject*/ public double getPerimeter() return 2*(width + height); /*Override the equals method defined in the Object class*/ public boolean equals(Rectangle