《Java语言程序设计(基础篇)》(第10版梁勇著)第十七章练习题答案

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java语言程序设计基础篇第十版课后答案

第一章1.1public class Test{public static void main(String[]args){System.out.println("Welcome to Java!"); System.out.println("Welcome to Computer Science!");System.out.println("Progr amming is fun.");}}1.2public class Test{public static void main(String[]args){for(int i=0;i<=4;i++){System.out.println("Welcome to Java!");}}}1.3public class Test{public static void main(String[]args){System.out.println("]");System.out.printl n("]");System.out.println("]]");System.out.println("]]");}}public class Test{public static void main(String[]args){System.out.println("A"); System.out.println("A A");System.out.println("AAAAA");System.out.println("A A");}}public class Test{public static void main(String[]args){System.out.println("V V");System.out.println("V V");System.out.println("V V");System.out.println(" V");}}1.4public class Test{public static void main(String[]args){System.out.println("a a^2a^3");System.out.println("111");System.out.println("248");System.out.println("3 927");System.out.println("41664");}}1.5public class Test{public static void main(String[]args){System.out.println((9.5*4.5-2.5*3)/(45.5-3.5) );}}1.6public class Test{public static void main(String[]args){int i=1,sum=0;for(;i<=9;i++)sum+ =i;System.out.println(sum);}1.7public class Test{public static void main(String[]args){System.out.println(4*(1.0-1.0/3+1.0/5-1.0/7+1.0/9-1.0/11));System.out.println(4*(1.0-1.0/3+1.0/5-1.0/7+1.0/9-1.0/11+1.0/13));}}1.8public class Test{public static void main(String[]args){final double PI=3.14; double radius=5.5;System.out.println(2*radius*PI);System.out.println(PI*radius*radius);}}1.9public class Test{public static void main(String[]args){System.out.println(7.9*4.5);System.out.p rintln(2*(7.9+4.5));}}1.10public class Test{public static void main(String[]args){double S=14/1.6;double T=45*60+30;double speed=S/T;System.out.println(speed);}1.11public class Test{public static void main(String[]args){int BN=312032486; //original person numbers double EveryYS,EveryYBP,EveryYDP,EveryYMP;EveryY S=365*24*60*60;EveryYBP=EveryYS/7;EveryYDP=EveryYS/13;Every YMP=EveryYS/45;int FirstYP,SecondYP,ThirdYP,FourthYP,FivthYP;FirstYP=(int)(BN+EveryYBP+EveryYMP-EveryYDP);SecondYP=(int)(FirstYP +EveryYBP+EveryYMP-EveryYDP);ThirdYP=(int)(SecondYP+EveryYBP+Ev eryYMP-EveryYDP);FourthYP=(int)(ThirdYP+EveryYBP+EveryYMP-EveryYD P);FivthYP=(int)(FourthYP+EveryYBP+EveryYMP-EveryYDP);System.out.pri ntln(FirstYP);System.out.println(SecondYP);System.out.println(ThirdYP);Syste m.out.println(FourthYP);System.out.println(FivthYP);}}1.12public class Test{public static void main(String[]args){double S=24*1.6; double T=(1*60+40)*60+35;double speed=S/T;System.out.println(sp eed);}}1.13import java.util.Scanner;public class Test{public static void main(String[]args){Scanner input=new Scan ner(System.in);System.out.println("input a,b,c,d,e,f value please:");double a=input.nextDouble();double b=input.nextDouble();double c=input.nextDouble();double d=input. nextDouble();double e=input.nextDouble();第二章package cn.Testcx;import java.util.Scanner;public class lesson2{public static void main(String[]args){@SuppressWarnings("resource")Scanner in put=new Scanner(System.in);System.out.print("请输入一个摄氏温度：");double Celsius=input.nextDouble();double Fahrenheit=(9.0/5)*Celsius+3 2;System.out.println("摄氏温度："+Celsius+"度"+"转换成华氏温度为："+Fahrenheit+"度");System.out.print("请输入圆柱的半径和高：");double radius=input.nextDouble();int higth=input.nextInt();double are as=radius*radius*Math.PI;double volume=areas*higth;System.out.println("圆柱体的面积为："+areas);System.out.println("圆柱体的体积为："+volume);System.out.print("输入英尺数：");double feet=input.nextDouble();double meters=feet*0.305;System.out.print ln(feet+"英尺转换成米："+meters);System.out.print("输入一个磅数：");double pounds=input.nextDouble();double kilograms=pounds*0.454;Syste m.out.println(pounds+"磅转换成千克为："+kilograms);System.out.println("输入分钟数：");long minutes=input.nextInt();long years=minutes/(24*60*365);long days=(minutes%(24*60*365))/(24*60);System.out.println(minutes+"分钟"+"有"+years+"年和"+days+"天");long totalCurrentTimeMillis=System.currentTimeMillis();long totalSeconds=t otalCurrentTimeMillis/1000;long currentSeconds=totalSeconds%60;long totalM inutes=totalSeconds/60;long currentMinutes=(totalSeconds%(60*60))/60;long currenthours=(totalMinutes/60)%24;System.out.print("输入时区偏移量：");byte zoneOffset=input.nextByte();long currentHour=(currenthours+(zoneOf fset*1))%24;System.out.println("当期时区的时间为："+currentHour+"时"+currentMinutes+"分"+currentSeconds+"秒");System.out.print("请输入v0,v1,t:");double v0=input.nextDouble();double v1=input.nextDouble();doublet=input.nextDouble();float a=(float)((v1-v0)/t);System.out.println("平均加速度a="+a);System.out.println("输入水的重量、初始温度、最终温度：");double water=input.nextDouble();double initialTemperature=input.nextDou ble();double finalTemperature=input.nextDouble();double Q=water*(finalTemp erature-initialTemperature)*4184;System.out.println("所需热量为："+Q);System.out.print("输入年数：");int numbers=input.nextInt();long oneYearsSecond=365*24*60*60;Longpop ulation=(long)((312032486+((oneYearsSecond/7.0)+(oneYearsSecond/45.0)-(oneYearsSecond/13.0))*numbers));System.out.println("第"+numbers+"年后人口总数为："+population);System.out.print("输入速度单位m/s和加速度a单位m/s2:");double v=input.nextDouble();double a1=input.nextDouble();double l engthOfAirplane=(Math.pow(v,2))/(2*a1);System.out.println("最短长度为："+lengthOfAirplane);System.out.print("输入存入的钱：");double money=input.nextInt();double monthRate=5.0/1200;for(int i=1;i<7; i++){double total=money*(Math.pow(1+monthRate,i));System.out.println("第"+i+"个月的钱为："+total);//告诉我书上的银行在哪里，我要去存钱，半年本金直接翻6倍、、、}System.out.print("用户请输入身高(英寸)、体重(磅):");double height=input.nextDouble();double weight=input.nextDouble(); double BMI=(weight*0.45359237)/(Math.pow((height*0.0254),2));System.out.println("BMI的值为"+BMI);System.out.print("输入x1和y1:");System.out.print("输入x2和y2:");double x1=input.nextDouble();double y1=input.nextDouble();double x2 =input.nextDouble();double y2=input.nextDouble();double point1=Math.pow((x2-x1),2);double point2=Math.pow((y2-y1),2);double distance=Math.pow((point1+point2),(1.0/2));//也可以Math.pow((point1+point2),0.5)System.out.println("两点间的距离为："+distance);System.out.print("输入六边形的边长：");double side=input.nextDouble();double area=(3*(Math.pow(3,0.5))*(Math.p ow(side,2)))/2;System.out.println("六边形的面积为："+area);}}。

《Java语言程序设计(基础篇)》(第10版梁勇著)第九章练习题答案

《Java语言程序设计（基础篇）》（第10版梁勇著）第九章练习题答案9.1public class Exercise09_01 {public static void main(String[] args) {MyRectangle myRectangle = new MyRectangle(4, 40);System.out.println("The area of a rectangle with width " +myRectangle.width + " and height " +myRectangle.height + " is " +myRectangle.getArea());System.out.println("The perimeter of a rectangle is " +myRectangle.getPerimeter());MyRectangle yourRectangle = new MyRectangle(3.5, 35.9);System.out.println("The area of a rectangle with width " +yourRectangle.width + " and height " +yourRectangle.height + " is " +yourRectangle.getArea());System.out.println("The perimeter of a rectangle is " +yourRectangle.getPerimeter());}}class MyRectangle {// Data membersdouble width = 1, height = 1;// Constructorpublic MyRectangle() {}// Constructorpublic MyRectangle(double newWidth, double newHeight) {width = newWidth;height = newHeight;}public double getArea() {return width * height;}public double getPerimeter() {return 2 * (width + height);}}9.2public class Exercise09_02 {public static void main(String[] args) {Stock stock = new Stock("SUNW", "Sun MicroSystems Inc."); stock.setPreviousClosingPrice(100);// Set current pricestock.setCurrentPrice(90);// Display stock infoSystem.out.println("Previous Closing Price: " +stock.getPreviousClosingPrice());System.out.println("Current Price: " +stock.getCurrentPrice());System.out.println("Price Change: " +stock.getChangePercent() * 100 + "%");}}class Stock {String symbol;String name;double previousClosingPrice;double currentPrice;public Stock() {}public Stock(String newSymbol, String newName) {symbol = newSymbol;name = newName;}public double getChangePercent() {return (currentPrice - previousClosingPrice) /previousClosingPrice;}public double getPreviousClosingPrice() {return previousClosingPrice;}public double getCurrentPrice() {return currentPrice;}public void setCurrentPrice(double newCurrentPrice) {currentPrice = newCurrentPrice;}public void setPreviousClosingPrice(double newPreviousClosingPrice) { previousClosingPrice = newPreviousClosingPrice;}}9.3public class Exercise09_03 {public static void main(String[] args) {Date date = new Date();int count = 1;long time = 10000;while (count <= 8) {date.setTime(time);System.out.println(date.toString());count++;time *= 10;}}}9.4public class Exercise09_04 {public static void main(String[] args) {Random random = new Random(1000);for (int i = 0; i < 50; i++)System.out.print(random.nextInt(100) + " ");}9.5public class Exercise09_05 {public static void main(String[] args) {GregorianCalendar calendar = new GregorianCalendar();System.out.println("Year is " + calendar.get(GregorianCalendar.YEAR)); System.out.println("Month is " + calendar.get(GregorianCalendar.MONTH)); System.out.println("Date is " + calendar.get(GregorianCalendar.DATE));calendar.setTimeInMillis(1234567898765L);System.out.println("Year is " + calendar.get(GregorianCalendar.YEAR)); System.out.println("Month is " + calendar.get(GregorianCalendar.MONTH)); System.out.println("Date is " + calendar.get(GregorianCalendar.DATE)); }}9.6public class Exercise09_06 {static String output = "";/** Main method */public static void main(String[] args) {Scanner input = new Scanner(System.in);// Prompt the user to enter yearSystem.out.print("Enter full year (i.e. 2001): ");int year = input.nextInt();// Prompt the user to enter monthSystem.out.print("Enter month in number between 1 and 12: ");int month = input.nextInt();// Print calendar for the month of the yearprintMonth(year, month);System.out.println(output);}/** Print the calendar for a month in a year */static void printMonth(int year, int month) {// Get start day of the week for the first date in the monthint startDay = getStartDay(year, month);// Get number of days in the monthint numOfDaysInMonth = getNumOfDaysInMonth(year, month);// Print headingsprintMonthTitle(year, month);// Print bodyprintMonthBody(startDay, numOfDaysInMonth);}/** Get the start day of the first day in a month */static int getStartDay(int year, int month) {// Get total number of days since 1/1/1800int startDay1800 = 3;long totalNumOfDays = getTotalNumOfDays(year, month);// Return the start dayreturn (int)((totalNumOfDays + startDay1800) % 7);}/** Get the total number of days since Jan 1, 1800 */static long getTotalNumOfDays(int year, int month) {long total = 0;// Get the total days from 1800 to year -1for (int i = 1800; i < year; i++)if (isLeapYear(i))total = total + 366;elsetotal = total + 365;// Add days from Jan to the month prior to the calendar month for (int i = 1; i < month; i++)total = total + getNumOfDaysInMonth(year, i);return total;}/** Get the number of days in a month */static int getNumOfDaysInMonth(int year, int month) {if (month == 1 || month==3 || month == 5 || month == 7 ||month == 8 || month == 10 || month == 12)return 31;if (month == 4 || month == 6 || month == 9 || month == 11)return 30;if (month == 2)if (isLeapYear(year))return 29;elsereturn 28;return 0; // If month is incorrect.}/** Determine if it is a leap year */static boolean isLeapYear(int year) {if ((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0))) return true;return false;}/** Print month body */static void printMonthBody(int startDay, int numOfDaysInMonth) { // Pad space before the first day of the monthint i = 0;for (i = 0; i < startDay; i++)output += " ";for (i = 1; i <= numOfDaysInMonth; i++) {if (i < 10)output += " " + i;elseoutput += " " + i;if ((i + startDay) % 7 == 0)output += "\n";}output += "\n";}/** Print the month title, i.e. May, 1999 */static void printMonthTitle(int year, int month) {output += " " + getMonthName(month)+ ", " + year + "\n";output += "-----------------------------\n";output += " Sun Mon Tue Wed Thu Fri Sat\n";}/** Get the English name for the month */static String getMonthName(int month) {String monthName = null;switch (month) {case 1: monthName = "January"; break;case 2: monthName = "February"; break;case 3: monthName = "March"; break;case 4: monthName = "April"; break;case 5: monthName = "May"; break;case 6: monthName = "June"; break;case 7: monthName = "July"; break;case 8: monthName = "August"; break;case 9: monthName = "September"; break;case 10: monthName = "October"; break;case 11: monthName = "November"; break;case 12: monthName = "December";}return monthName;}}9.7public class Exercise09_07 {public static void main (String[] args) {Account account = new Account(1122, 20000);Account.setAnnualInterestRate(4.5);account.withdraw(2500);account.deposit(3000);System.out.println("Balance is " + account.getBalance()); System.out.println("Monthly interest is " +account.getMonthlyInterest());System.out.println("This account was created at " +account.getDateCreated());}}class Account {private int id;private double balance;private static double annualInterestRate;private java.util.Date dateCreated;public Account() {dateCreated = new java.util.Date();}public Account(int newId, double newBalance) {id = newId;balance = newBalance;dateCreated = new java.util.Date();}public int getId() {return this.id;}public double getBalance() {return balance;}public static double getAnnualInterestRate() {return annualInterestRate;}public void setId(int newId) {id = newId;}public void setBalance(double newBalance) {balance = newBalance;}public static void setAnnualInterestRate(double newAnnualInterestRate) { annualInterestRate = newAnnualInterestRate;}public double getMonthlyInterest() {return balance * (annualInterestRate / 1200);}public java.util.Date getDateCreated() { return dateCreated;}public void withdraw(double amount) {balance -= amount;}public void deposit(double amount) {balance += amount;}}9.8public class Exercise09_08 {public static void main(String[] args) { Fan1 fan1 = new Fan1();fan1.setSpeed(Fan1.FAST);fan1.setRadius(10);fan1.setColor("yellow");fan1.setOn(true);System.out.println(fan1.toString());Fan1 fan2 = new Fan1();fan2.setSpeed(Fan1.MEDIUM);fan2.setRadius(5);fan2.setColor("blue");fan2.setOn(false);System.out.println(fan2.toString()); }}class Fan1 {public static int SLOW = 1;public static int MEDIUM = 2;public static int FAST = 3;private int speed = SLOW;private boolean on = false;private double radius = 5;private String color = "white";public Fan1() {}public int getSpeed() {return speed;}public void setSpeed(int newSpeed) {speed = newSpeed;}public boolean isOn() {return on;}public void setOn(boolean trueOrFalse) {this.on = trueOrFalse;}public double getRadius() {return radius;}public void setRadius(double newRadius) { radius = newRadius;}public String getColor() {return color;}public void setColor(String newColor) {color = newColor;}@Overridepublic String toString() {return"speed " + speed + "\n"+ "color " + color + "\n"+ "radius " + radius + "\n"+ ((on) ? "fan is on" : " fan is off"); }}public class Exercise09_09 {public static void main(String[] args) {RegularPolygon polygon1 = new RegularPolygon();RegularPolygon polygon2 = new RegularPolygon(6, 4);RegularPolygon polygon3 = new RegularPolygon(10, 4, 5.6, 7.8);System.out.println("Polygon 1 perimeter: " +polygon1.getPerimeter());System.out.println("Polygon 1 area: " + polygon1.getArea());System.out.println("Polygon 2 perimeter: " +polygon2.getPerimeter());System.out.println("Polygon 2 area: " + polygon2.getArea());System.out.println("Polygon 3 perimeter: " +polygon3.getPerimeter());System.out.println("Polygon 3 area: " + polygon3.getArea());}}class RegularPolygon {private int n = 3;private double side = 1;private double x;private double y;public RegularPolygon() {}public RegularPolygon(int number, double newSide) {n = number;side = newSide;}public RegularPolygon(int number, double newSide, double newX, double newY) {n = number;side = newSide;x = newX;y = newY;}public int getN() {return n;}public void setN(int number) {n = number;}public double getSide() {return side;}public void setSide(double newSide) {side = newSide;}public double getX() {return x;}public void setX(double newX) {x = newX;}public double getY() {return y;}public void setY(double newY) {y = newY;}public double getPerimeter() {return n * side;}public double getArea() {return n * side * side / (Math.tan(Math.PI / n) * 4); }}9.10public class Exercise09_10 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter a, b, c: ");double a = input.nextDouble();double b = input.nextDouble();double c = input.nextDouble();QuadraticEquation equation = new QuadraticEquation(a, b, c);double discriminant = equation.getDiscriminant();if (discriminant < 0) {System.out.println("The equation has no roots");}else if (discriminant == 0){System.out.println("The root is " + equation.getRoot1());}else// (discriminant >= 0){System.out.println("The roots are " + equation.getRoot1()+ " and " + equation.getRoot2());}}}class QuadraticEquation {private double a;private double b;private double c;public QuadraticEquation(double newA, double newB, double newC) {a = newA;b = newB;c = newC;}double getA() {return a;}double getB() {return b;}double getC() {return c;}double getDiscriminant() {return b * b - 4 * a * c;}double getRoot1() {if (getDiscriminant() < 0)return 0;else {return (-b + getDiscriminant()) / (2 * a);}}double getRoot2() {if (getDiscriminant() < 0)return 0;else {return (-b - getDiscriminant()) / (2 * a);}}}9.11public class Exercise09_11 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter a, b, c, d, e, f: ");double a = input.nextDouble();double b = input.nextDouble();double c = input.nextDouble();double d = input.nextDouble();double e = input.nextDouble();double f = input.nextDouble();LinearEquation equation = new LinearEquation(a, b, c, d, e, f);if (equation.isSolvable()) {System.out.println("x is " +equation.getX() + " and y is " + equation.getY());}else {System.out.println("The equation has no solution");}}}class LinearEquation {private double a;private double b;private double c;private double d;private double e;private double f;public LinearEquation(double newA, double newB, double newC, double newD, double newE, double newF) {a = newA;b = newB;c = newC;d = newD;e = newE;f = newF;}double getA() {return a;}double getB() {return b;}double getC() {return c;}double getD() {return d;}double getE() {return e;}double getF() {return f;}boolean isSolvable() {return a * d - b * c != 0;}double getX() {double x = (e * d - b * f) / (a * d - b * c);return x;}double getY() {double y = (a * f - e * c) / (a * d - b * c);return y;}}9.12public class Exercise09_12 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter the endpoints of the first line segment: ");double x1 = input.nextDouble();double y1 = input.nextDouble();double x2 = input.nextDouble();double y2 = input.nextDouble();System.out.print("Enter the endpoints of the second line segment: ");double x3 = input.nextDouble();double y3 = input.nextDouble();double x4 = input.nextDouble();double y4 = input.nextDouble();// Build a 2 by 2 linear equationdouble a = (y1 - y2);double b = (-x1 + x2);double c = (y3 - y4);double d = (-x3 + x4);double e = -y1 * (x1 - x2) + (y1 - y2) * x1;double f = -y3 * (x3 - x4) + (y3 - y4) * x3;LinearEquation equation = new LinearEquation(a, b, c, d, e, f);if (equation.isSolvable()) {System.out.println("The intersecting point is: (" +equation.getX() + ", " + equation.getY() + ")");}else {System.out.println("The two lines do not cross ");}}}9.13public class Exercise09_13 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter the number of rows and columns of the array: ");int numberOfRows = input.nextInt();int numberOfColumns = input.nextInt();double[][] a = new double[numberOfRows][numberOfColumns];System.out.println("Enter the array: ");for (int i = 0; i < a.length; i++)for (int j = 0; j < a[i].length; j++)a[i][j] = input.nextDouble();Location location = locateLargest(a);System.out.println("The location of the largest element is " + location.maxValue + " at ("+ location.row + ", " + location.column + ")");}public static Location locateLargest(double[][] a) {Location location = new Location();location.maxValue = a[0][0];for (int i = 0; i < a.length; i++)for (int j = 0; j < a[i].length; j++) {if (location.maxValue < a[i][j]) {location.maxValue = a[i][j];location.row = i;location.column = j;}}return location;}}class Location {int row, column;double maxValue;}9.14public class Exercise09_14 {public static void main(String[] args) {int size = 100000;double[] list = new double[size];for (int i = 0; i < list.length; i++) {list[i] = Math.random() * list.length;}StopWatch stopWatch = new StopWatch();selectionSort(list);stopWatch.stop();System.out.println("The sort time is " + stopWatch.getElapsedTime()); }/** The method for sorting the numbers */public static void selectionSort(double[] list) {for (int i = 0; i < list.length - 1; i++) {// Find the minimum in the list[i..list.length-1]double currentMin = list[i];int currentMinIndex = i;for (int j = i + 1; j < list.length; j++) {if (currentMin > list[j]) {currentMin = list[j];currentMinIndex = j;}}// Swap list[i] with list[currentMinIndex] if necessary;if (currentMinIndex != i) {list[currentMinIndex] = list[i];list[i] = currentMin;}}}}class StopWatch {private long startTime = System.currentTimeMillis(); private long endTime = startTime;public StopWatch() {}public void start() {startTime = System.currentTimeMillis();}public void stop() {endTime = System.currentTimeMillis();}public long getElapsedTime() {return endTime - startTime;}}。

java程序设计(雍俊海)课后部分标准答案

第一章1 • 1谁是java语言创始人J a mes Gosli n g, J a va语言的创始人之一1.2j ava语言有哪些优缺点？P 2页(1)简单性(2)网络特性(3)面向对象性(4)平台无关性/可移植性(5)鲁棒性也指程序稳定性(6)安全性(7)多线程性，采用多线程机制是提高程序运行效率的方法，但增加了程序的设计难度(8)解释性，缺点，解释执行语言要不编译执行语言需要额外的语句解释不龙及运行时间。

1. 4请简述环境变相path和c 1 asspa t h作用环境变量运行路径(path)和类路径(classpath)1. 5java程序可以分为几种，分别是什么？两种，应用程序和小应用程序applt1. 6 査看j ava 在线帮助文档，列举岀system, o ut. pr i n tl n 和s ys t em. out. print 的不同点。

S y s t em. o u t. printin 自动换行，system, ou t . print 不自动换行。

1.7试着编写一个j ava程序，在控制台窗口中输岀如下信息。

Publ i c clas s TestPubli c sta t i c void m a in(strng args[]){ system, out. print In (M*** **** *次* **** *** ****")；s ys t em. o ut・ pr i ntln(v ** p ra c ti c e makes pe r f e c t ,?)：system・ ou t ・ p ri n tin ( ” ******* ***** ***** * **次”)；}1.8编写一个j ava程序，在网页中显示如下信息。

import ja v a ・ a w t .Graph i cs;import javax. swing・ JAppl e t;p u b 1 i c c 1 ass J_H e lloAp p let extend s JA p plet{pu b lie v o i d p a i nt (Gr a phics g){g. cle a rRect (0, 0F g e t W i d th() > g etH e igh t ());g . draw S trin g ( "** * * **** **** * * * * * * 次 ** *** * * * ********** * * ************", ] 0, 2 0);g. d rawStri n g (" * * 熟能生巧"，10, 30);g. dra w Stri ng ( " * **** * **** * 次 ********** * *** * *** * **** * * 次*************", ] 0, 40);}}网页：< h tml><head><t i tie >java 小程序 </ t itle> </h e ad> <body><APP LET CODE「J_Hel 1 oAp p let. class' WIDTH二〃200〃h e i g ht = '40，z> </appl e t > </bo d y></html>1. 9请阐述编写j a va程序的具体步骤：第二章：2.2 U"算下而java表达式的值,并写出表达式结果在j ava中的数据类型(1)1+4/5+ ( i nt) 5. 2/2. 5=3. 0 //数据类型:浮点类型(2)1+4/5+ ( i nt) (5.2/2. 5)=3 / / 数据类型：整型(3)1+4/5 + 5. 2/2. 5=3. 08 //数据类型:浮点类型(4 ) 1. 0+4/5+5. 2/2. 5=3. 08 //数据类型:浮点类型(5)1+4/5. 0 +5.2/2. 5=3. 8 8 //数据类型:浮点类型(6)设已定义了变量i nt a =12,请计算表达式(++a) + (a++)因为a=12则 + +a=13现在护1 3所以a++二1 3所以表达式(++a)+(a++)=2 6 //数据类型：整型(7)10 >>2=2 //数据类型:整型(8)10&1 1 |12结果为t rue //数据类型:布尔型(9)5“7结果为2 即为真(10)(-5)1 (^5)结果为一5 //数据类型：整型J N字节码正确结果。

Java语言程序设计基础篇(第10版) 梁勇课后习题答案

System.out.println("Programming is fun .");
}
}
1.2 public class Test{
public static void main(String[] args){
for(int i = 0;i <= 4;i++){
System.out.println("Welcome to Java !");
public static void main(String[] args){ double S = 14 / 1.6;
double T = 45 * 60 + 30; double speed = S / T; System.out.println(speed); } } 1.11 public class Test{ public static void main(String[] args){ int BN = 312032486; //original person numbers double EveryYS,EveryYBP,EveryYDP,EveryYMP; EveryYS = 365 * 24 * 60 * 60; EveryYBP = EveryYS / 7; EveryYDP = EveryYS / 13; EveryYMP = EveryYS / 45; int FirstYP,SecondYP,ThirdYP,FourthYP,FivthYP; FirstYP = (int)(BN + EveryYBP + EveryYMP - EveryYDP); SecondYP = (int)(FirstYP + EveryYBP + EveryYMP - EveryYDP); ThirdYP = (int)(SecondYP + EveryYBP + EveryYMP - EveryYDP); FourthYP = (int)(ThirdYP + EveryYBP + EveryYMP - EveryYDP); FivthYP = (int)(FourthYP + EveryYBP + EveryYMP - EveryYDP); System.out.println(FirstYP); System.out.println(SecondYP); System.out.println(ThirdYP); System.out.println(FourthYP); System.out.println(FivthYP); } } 1.12 public class Test{ public static void main(String[] args){ double S = 24 * 1.6; double T = (1 * 60 + 40) * 60 + 35; double speed = S / T; System.out.println(speed); } } 1.13 import java.util.Scanner; public class Test{ public static void main(String[] args){ Scanner input = new Scanner(System.in); System.out.println("input a,b,c,d,e,f value please:"); double a = input.nextDouble(); double b = input.nextDouble(); double c = input.nextDouble(); double d = input.nextDouble(); double e = input.nextDouble();

java语言程序设计基础篇第十版练习答案精编

j a v a语言程序设计基础篇第十版练习答案精编Document number：WTT-LKK-GBB-08921-EIGG-2298601import class Exercise14_01 extendsApplication {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}02import class Exercise14_02 extends Application {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}03import class Exercise14_03 extends Application {@Override One is to use the hint in the book.ArrayList<Integer> list = new ArrayList<>(); for (int i = 1; i <= 52; i++) {(i);}HBox pane = new HBox(5);;().add(new ImageView("image/card/" + (0) +".png"));().add(new ImageView("image/card/" + (1) +".png"));().add(new ImageView("image/card/" + (2) +".png"));Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}04import class Exercise14_04 extends Application {@Override dd(txt);}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}05import class Exercise14_05 extends Application {@Override dd(txt);}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}05import class Exercise14_05 extends Application {@Override dd(txt);}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}06import class Exercise14_06 extends Application {@Override dd(rectangle);}}Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}07import class Exercise14_07 extends Application {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}08import class Exercise14_08 extends Application {@Override ng"), j, i);}}Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}09import class Exercise14_09 extends Application {@Override Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}class FanPane extends Pane {double radius = 50;public FanPane() {Circle circle = new Circle(60, 60, radius);;;getChildren().add(circle);Arc arc1 = new Arc(60, 60, 40, 40, 30, 35);; ddAll(arc1, arc2, arc3, arc4);}}10import class Exercise14_10 extends Application {@Override ddAll, ;Arc arc2 = new Arc(100, 140, 50, 20, 180, 180); ;;().addAll(ellipse, arc1, arc2,new Line(50, 40, 50, 140), new Line(150, 40, 150, 140));Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}11import class Exercise14_11 extends Application {@Override ddAll(circle, ellipse1, ellipse2,circle1, circle2, line1, line2, line3, arc);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}12import class Exercise14_12 extends Application {@Override ddAll(r1, text1, r2, text2, r3, text3, r4, text4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}13import class Exercise14_13 extends Application {@Override ddAll(arc1, text1, arc2, text2, arc3, text3, arc4, text4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}14import class Exercise14_14 extends Application {@Override ddAll(r1, r2, line1, line2, line3, line4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}15import class Exercise14_15 extends Application {@Override ddAll(polygon, text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}16import class Exercise14_16 extends Application {@Override ind().divide(3));().bind());().bind().divide(3));;Line line2 = new Line(0, 0, 0, 0);().bind().multiply(2).divide(3));().bind());().bind().multiply(2).divide(3));;Line line3 = new Line(0, 0, 0, 0);().bind().divide(3));().bind().divide(3));().bind());;Line line4 = new Line(0, 0, 0, 0);().bind().multiply(2).divide(3));().bind().multiply(2).divide(3));().bind());;().addAll(line1, line2, line3, line4);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}17import class Exercise14_17 extends Application {@Override ddAll(arc, line1, line2, line3, circle, line4, line5, line6, line7, line8);Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}18import class Exercise14_18 extends Application {@Override ddAll(polyline, line1, line2,line3, line4, line5, line6, text1, text2);Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}19import class Exercise14_19 extends Application {@Override ddAll(polyline1, polyline2, line1,line2,line3, line4, line5, line6, text1, text2,text3,text4, text5, text6, text7);Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}20import class Exercise14_20 extends Application {@Override dd(new Line(x1, y1, x2, y2));dd(new Line(x2, y2, (x2 + (arctan + set45) * arrlen)),((y2)) + (arctan + set45) * arrlen)));().add(new Line(x2, y2, (x2 + (arctan - set45) * arrlen)),((y2)) + (arctan - set45) * arrlen)));}/*** The main method is only needed for the IDE with limited* JavaFX support. Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}21import class Exercise14_21 extends Application {@Override istance(x2, y2) + "");().addAll(circle1, circle2, line, text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}22import class Exercise14_22 extends Application {@Override ddAll(circle1, circle2, line, text1, text2);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}23import class Exercise14_23 extends Application {@Override ddAll(r1, r2, text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}24import class Exercise14_24 extends Application {@Override ddAll(polygon, new Circle(x5, y5, 10), text);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}25import class Exercise14_25 extends Application {@Override ddAll(circle, polygon);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}26import class Exercise14_26 extends Application {@Override ddAll(clock1, clock2);Not needed for running from the command line. */public static void main(String[] args) {launch(args);}27import class Exercise14_27 extends Application {@OverrideNot needed for running from the command line. */public static void main(String[] args) {launch(args);}}class DetailedClockPane extends Pane {private int hour;private int minute;private int second;lear();getChildren().addAll(circle, sLine, mLine, hLine);dd(new Line(xOuter, yOuter, xInner, yInner));}dd(text);}}}28import class Exercise14_28 extends Application {@OverrideNot needed for running from the command line.*/public static void main(String[] args) {launch(args);}}class ClockPaneWithBooleanProperties extends Pane { private int hour;private int minute;private int second;private boolean hourHandVisible = true;private boolean minuteHandVisible = true; private boolean secondHandVisible = true;public boolean isHourHandVisible() {return hourHandVisible;}public void setHourHandVisible(boolean hourHandVisible) {= hourHandVisible;paintClock();}public boolean isMinuteHandVisible() {return minuteHandVisible;}public void setMinuteHandVisible(boolean minuteHandVisible) {= minuteHandVisible;paintClock();}public boolean isSecondHandVisible() {return secondHandVisible;public void setSecondHandVisible(boolean secondHandVisible) {= secondHandVisible;paintClock();}lear();getChildren().addAll(circle, t1, t2, t3, t4);if (secondHandVisible) {getChildren().add(sLine);}if (minuteHandVisible) {getChildren().add(mLine);}if (hourHandVisible) {getChildren().add(hLine);}}}import class Exercise14_29 extends Application {final static double HGAP = 20;final static double VGAP = 20;final static double RADIUS = 5;final static double LENGTH_OF_SLOTS = 40;final static double LENGTH_OF_OPENNING = 15;final static double Y_FOR_FIRST_NAIL = 50;final static double NUMBER_OF_SLOTS = 9;final static double NUMBER_OF_ROWS =NUMBER_OF_SLOTS - 2;@Override dd(c);}}dd(new Line(x, y, x, y + LENGTH_OF_SLOTS)); }dd(new Line(centerX - (NUMBER_OF_ROWS - 1) * HGAP / 2 - HGAP,y + LENGTH_OF_SLOTS, centerX -(NUMBER_OF_ROWS - 1) * HGAP / 2 + NUMBER_OF_ROWS * HGAP,y + LENGTH_OF_SLOTS));dd(new Line(centerX + HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX - (NUMBER_OF_ROWS - 1) * HGAP / 2 + NUMBER_OF_ROWS * HGAP, y));().add(new Line(centerX - HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX - (NUMBER_OF_ROWS - 1) * HGAP / 2 - HGAP, y));dd(new Line(centerX - HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX - HGAP / 2, Y_FOR_FIRST_NAIL - LENGTH_OF_OPENNING));().add(new Line(centerX + HGAP / 2,Y_FOR_FIRST_NAIL + RADIUS,centerX + HGAP / 2, Y_FOR_FIRST_NAIL - LENGTH_OF_OPENNING));Not needed for running from the command line.*/public static void main(String[] args) { launch(args);}}。

Java语言程序设计课后习题答案全集

Java语言程序设计课后习题答案全集Java语言程序设计是一门广泛应用于软件开发领域的编程语言，随着其应用范围的不断扩大，对于掌握Java编程技巧的需求也逐渐增加。

为了帮助读者更好地掌握Java编程，本文将提供Java语言程序设计课后习题的全集答案，供读者参考。

一、基础知识题1. 代码中的注释是什么作用？如何使用注释.答：注释在代码中是用来解释或者说明代码的功能或用途的语句，编译器在编译代码时会自动忽略注释。

在Java中，有三种注释的方式：- 单行注释：使用"// " 可以在代码的一行中加入注释。

- 多行注释：使用"/* */" 可以在多行中添加注释。

- 文档注释：使用"/** */" 可以添加方法或类的文档注释。

2. 什么是Java的数据类型？请列举常见的数据类型。

答：Java的数据类型用来指定变量的类型，常见的数据类型有：- 基本数据类型：包括整型（byte、short、int、long）、浮点型（float、double）、字符型（char）、布尔型（boolean）。

- 引用数据类型：包括类（class）、接口（interface）、数组（array）等。

二、代码编写题1. 编写Java程序，输入两个整数，求和并输出结果。

答：```javaimport java.util.Scanner;public class SumCalculator {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);System.out.print("请输入第一个整数：");int num1 = scanner.nextInt();System.out.print("请输入第二个整数：");int num2 = scanner.nextInt();int sum = num1 + num2;System.out.println("两个整数的和为：" + sum);}}```三、综合应用题1. 编写Java程序，实现学生信息管理系统，要求包括以下功能：- 添加学生信息（姓名、年龄、性别、学号等）；- 修改学生信息；- 删除学生信息；- 查询学生信息。

(完整版)Java语言程序设计(基础篇)原书第十版梁勇著第一章答案

Java语言程序设计课后习题答案全集

J a v a语言程序设计课后习题答案全集Document serial number【UU89WT-UU98YT-UU8CB-UUUT-UUT108】指出JAVA语言的主要特点和JAVA程序的执行过程。

答：(1)强类型;(2)编译和解释;(3)自动无用内存回收功能;(4)面向对象;(5)与平台无关;(6)安全性;(7)分布式计算;(8)多线程;程序执行过程如图所示：编写源文件，编译器编译源文件转换成字节码，解释器执行字节码。

说出开发与运行JAVA程序的重要步骤。

答：(1)编写源文件:使用一个文本编译器,如Edit或记事本,不可以使用Word.将编好的源文件保存起来,源文件的扩展名必须是.java;(2)编译Java源文件:使用Java编译器编译源文件得到字节码文件;(3)运行Java程序:Java程序分为两类——Java应用程序必须通过Java解释器来解释执行其字节码文件;Java小应用程序必须通过支持Java标准的浏览器来解释执行。

如何区分应用程序和小应用程序答：应用程序在与源文件名字相同的类中,有main()方法,该方法代表应用程序的入口; 小应用程序必须有一个Applet类的子类，该类称作主类，必须用public修饰。

说出JAVA源文件的命名规则。

答：源文件命名规则和类命名规则一样，所有的单词首字母都用大写字母，且必须和源文件的public类同名。

JAVA语言使用什么字符集共有多少个不同的字符答：Java语言使用Unicode字符集，共有65535个字符。

JAVA语言标识符的命名规则是什么(1)由字母(包括英文字母、下划线字符、美元字符、文字字符)和数字字符组成(2)限定标识符的第一个字符不能是数字字符(3)不能和关键字重名(4)长度不能超过255个字符JAVA有那些基本数据类型，它们的常量又是如何书写的指出下列内容哪些是JAVA语言的整型常量，哪些是浮点数类型常量，哪些两者都不是。

整型常量： 4)0xABCL,8)003,10)077,12)056L浮点数类型常量：3)-1E-31,5).32E31 13)0.,14).0两者都不是: 1),2),6),7),9),11)第二章运算和语句Java 的字符能参加算术运算吗可以。

JAVA语言程序设计(基础篇)答案

3.4import javax.swing.*;public class AdditionTutor{public static void main(String[] args){int number1=(int)(System.currentTimeMillis()%100);int number2=(int)(System.currentTimeMillis()*5%100);String answerString=JOptionPane.showInputDialog("what is "+ number1 +"+ "+ number2+" ?");int answer=Integer.parseInt(answerString);JOptionPane.showMessageDialog(null,number1 +" + "+ number2 +" = "+answer+" is "+(number1+number2==answer));}}3.10import javax.swing.JOptionPane;public class ComputeTaxWithSelectionStatement{public static void main(String[] args){//Prompt the user to enter filing statusString statusString = JOptionPane.showInputDialog("Enter the filing status:\n"+"(0-single filer,1-married jointly,\n"+"2-married separately,3-head of household)");int status = Integer.parseInt(statusString);//Prompt the user to enter taxable incomeString incomeString = JOptionPane.showInputDialog("Enter the taxable income:");double income = Double.parseDouble(incomeString);//Comput taxdouble tax=0;if (status == 0){//Compute tax for single filersif (income <= 6000)tax = income * 0.10;else if (income <= 27950)tax = 6000 * 0.10 + (income - 6000) * 0.15;else if (income <= 67700)tax = 6000 * 0.10 + (27950 - 6000) * 0.15 +(income - 27950) * 0.27;else if (income <= 141250)tax = 6000 * 0.10 + (27950 - 6000) * 0.15 +(67700 - 27950) * 0.27 + (income - 67700) * 0.30;else if (income <=307050)tax = 6000 * 0.10 + (27950 - 6000) * 0.15 +(67700 - 27950) * 0.27 + (141250 - 67700) * 0.30 +(income - 141250) * 0.35;elsetax = 6000 * 0.10 + (27950 - 6000) * 0.15 +(67700 - 27950) * 0.27 + (141250 -67700) * 0.30 +(307050 - 141250) * 0.35 + (income - 307050) * 0.386;}else if (status == 1){//Compute tax for married file jointly if (income <= 12000)tax = income * 0.10;else if (income <= 46700)tax = 12000 * 0.10 + (income - 12000) * 0.15;else if (income <= 112850)tax = 12000 * 0.10 + (46700 - 12000) * 0.15 +(income - 46700) * 0.27;else if (income <= 171950)tax = 12000 * 0.10 + (46700 - 12000) * 0.15 +(112850 - 46700) * 0.27 + (income - 112850) * 0.30;else if (income <= 307050)tax = 12000 * 0.10 + (46700 - 12000) * 0.15 +(112850 - 46700) * 0.27 + (141250 - 112850) * 0.30 +(income - 307050) * 0.35;elsetax = 12000 * 0.10 + (46700 - 12000) * 0.15 +(112850 - 46700 ) * 0.27 + (171950 - 112850) * 0.30 +(307050 - 171950) * 0.35 + (income - 307050) * 0.386;}else if (status == 2){//Compute tax for married separately if (income <= 6000)tax = income * 0.10;else if (income <= 23350)tax = 6000 * 0.10 + (income - 6000) * 0.15;else if (income <= 56425)tax = 6000 * 0.10 + (23350 - 6000) * 0.15 +(income - 23350) * 0.27;else if (income <= 85975)tax = 6000 * 0.10 + (23350 - 6000) * 0.15 +(56425 - 23350) * 0.27 + (income - 56425) * 0.30;else if (income <= 153525)tax = 6000 * 0.10 + (23350 - 6000) * 0.15 +(56425 - 23350) * 0.27 + (85975 - 56425) * 0.30 +(income - 85975) * 0.35;elsetax = 6000 * 0.10 + (23350 - 6000) * 0.15 +(56425 - 23350) * 0.27 + (85975 - 56425) * 0.30 +(153525 - 85975) * 0.35 + (income - 153525) * 0.386;}else if (status == 3){//Compute tax for head of householdif (income <= 10000)tax = income * 0.10;else if (income <= 37450)tax = 10000 * 0.10 + (income - 10000) * 0.15;else if (income <= 96700)tax = 10000 * 0.10 + (37450 - 10000) * 0.15 +(income - 37450) * 0.27;else if (income <= 156600)tax = 10000 * 0.10 + (37450 - 10000) * 0.15 +(96700 - 37450) * 0.27 + (income - 96700) * 0.30;else if (income <= 307050)tax = 10000 * 0.10 + (37450 - 10000) * 0.15 +(96700 - 37450) * 0.27 + (156600 - 96700) * 0.30 +(income - 156600) * 0.35;elsetax = 10000 * 0.10 + (37450 - 10000) * 0.15 +(96700 - 37450) * 0.27 + (156600 - 96700) * 0.30 +(307050 - 156600) * 0.35 + (income - 307050) * 0.386;}else{System.out.println("Error: invalid status");System.exit(0);}//Display the resultJOptionPane.showMessageDialog(null,"Tax is " +(int)(tax * 100) / 100.0);}}4.11public class ZhengChu{public static void main(String[] args){int count=0;for(int i=100;i<=200;i++){if((i%5==0||i%6==0)&&i%30!=0){System.out.print(" "+ i);count++;if(count%10==0)System.out.println();}}}}4.14public class ASCII{public static void main(String[] args){int count = 0;for(int i = 33; i <= 126; i++){count++;char ch = (char)i;System.out.print(" " + ch);if(count % 10 == 0)System.out.println();}}}4.17import javax.swing.JOptionPane;public class FindSalesAmount{/**Main method*/public static void main(String[] args){//The commission soughtString COMMISSION_SOUGHTString = JOptionPane.showInputDialog("Enter the COMMISSION_SOUGHT :");double COMMISSION_SOUGHT = Double.parseDouble(COMMISSION_SOUGHTString);double commission = 0;double salesAmount;for (salesAmount = 0.01;commission <= COMMISSION_SOUGHT;){salesAmount += 0.01; //防止犯off-by-one错误，先判断在做自加！if (salesAmount >= 10000.01)commission =5000 * 0.08 + 5000 * 0.1 + (salesAmount - 10000) * 0.12;else if (salesAmount >= 5000.01)commission = 5000 * 0.08 + (salesAmount - 5000) * 0.10;elsecommission = salesAmount * 0.08;}String output ="The sales amount $" + (int)(salesAmount * 100) / 100.0 +"\n is needed to make a commission of $" + COMMISSION_SOUGHT;JOptionPane.showMessageDialog(null,output);}}5.6import javax.swing.JOptionPane;public class PrintPyramid{public static void main(String[] args){String input = JOptionPane.showInputDialog("Enter the number of lines:");int numberOfLines = Integer.parseInt(input);displayPattern(numberOfLines);}public static void displayPattern(int n){for (int row = 1;row <= n;row++){for (int column = 1;column <= n - row;column++)System.out.print(" ");for (int num = row;num >= 1;num--)System.out.print((num >= 10) ? " " + num : " " + num);System.out.println();}}}5.18public class MathSuanFa{public static void main(String[] args){double A = Math.sqrt(4);double B = (int)Math.sin(2 * Math.PI);double C = (int)Math.cos(2 * Math.PI);double D = (int)Math.pow(2, 2);double E = (int)Math.log(Math.E);double F = (int)(Math.exp(1)*100000)/100000.0;double G = (int)Math.max(2, Math.min(3, 4));double H = (int)Math.rint(-2.5);double I = (int)Math.ceil(-2.5);double J = (int)Math.floor(-2.5);int K = (int)Math.round(-2.5f);int L = (int)Math.round(-2.5);double M = (int)Math.rint(2.5);double N = (int)Math.ceil(2.5);double O = (int)Math.floor(2.5);int P = (int)Math.round(2.5f);int Q = (int)Math.round(2.5);int R = (int)Math.round(Math.abs(-2.5));System.out.println(A +" "+ B +" "+ C +" "+ D +" "+ E +" "+ F +" "+ G +" "+ H +" "+ I +" "+ J +" "+ K +" "+ L +" "+ M +" "+ N +" "+ O +" "+ P +" "+ Q +" "+ R);}}6.9import javax.swing.JOptionPane;public class Array{public static void main (String[] args){String incomeString = JOptionPane.showInputDialog("Enter the number of array size:");int income = Integer.parseInt(incomeString);int arraySize = income;int [] myList = new int [arraySize];int m;for ( m = 0; m < arraySize; m++){String elementString = JOptionPane.showInputDialog("Enter the " + (m + 1) + " element of the array");int element = Integer.parseInt(elementString);myList[m] = element;}int minElement = myList[0];for (int i=1; i < arraySize; i++){if (myList[i] < minElement)minElement = myList[i];}JOptionPane.showMessageDialog(null,"The min element is: " + minElement); }}。

Java语言程序设计(基础篇)(第10版梁勇著)第二章练习题答案

第二章基本程序设计练习题答案本人在自学编程过程中发现本书答案很难找找到的要么不完整要么错误百出所以我将自己所做的练习题答案提供给有需要者供大家交流
《Java语言程序设计（基础篇）》（第10版梁勇著）第二章基本程序设计练习题答案
本人在自学编程过程中，发现本书答案很难找，找到的要么不完整、要么错误百出，所以我将自己所做的练习题答案，提供给有需要者，供大家交流。本章答案均为本人一字一字所敲，答案均经过验证，虽为初学者，但代码均按照书中规范要求书写，如有错误或更好的建议，请指正交流。
// 第二章 P59 练习题2.1 （将摄氏温度转为华氏温度） import java.util.Scanner;
public class CelsiusToFahrenheit {
public static void main(String[] args) { // 华氏温度和摄氏温度的转换公式为：华氏温度 = (9/5)*摄氏温度+32 Scanner input = new Scanner(System.in);
System.out.print("Enter the time zone offset to GMT: "); long timeZoneOffset = input.nextLong(); // 此处用long还是int？
long totalMilliseconds = System.currentTimeMillis(); long totalSeconds = totalMilliseconds / 1000; long currentSecond = totalSeconds % 60; long totalMinutes = totalSeconds / 60; long currentMinute = totalMinutes % 60; long totalHours = totalMinutes / 60; long currentHour = totalHours % 24; long hour = currentHour + timeZoneOffset;

java语言程序设计基础篇复习题答案

java语言程序设计基础篇复习题答案【篇一：《java语言程序设计基础教程》(龚永罡_陈昕)习题答案】txt>1.9 练习思考题1、a，b，c2、d3、a，b 4 a 5、b6、开发与运行java程序需要经过的三个主要步骤为____________、____校验________和___解释执行____。

7、如果一个java applet源程序文件只定义有一个类，该类的类名为myapplet，则类myapplet必须是类的子类并且存储该源程序文件的文件名为。

8、如果一个java applet程序文件中定义有3个类，则使用sun 公司的jdk编译器编译该源程序文件将产生___3___个文件名与类名相同而扩展名为__class____的字节码文件。

11、编写一个简单的java应用程序，该程序在命令行窗口输出两行文字：“你好，很高兴学习java”和“we are students”。

解答：class myfirstjava{public static void main(string args[]){system.out.println(“你好，很高兴学习java”);system.out.println(“we are students”);}}第2章 java基本的程序设计结构2.7练习思考题1、a，b，d2、Ｃ3、a4、b5、d6、d，f7、b8、d9、d10、a11、Ｄ12、a 13、Ｂ 14、c15、d16、a17、在java的基本数据类型中，char型采用unicode编码方案，每个unicode码占用字节内存空间，这样，无论是中文字符还是英文字符，都是占用字节内存空间。

18、设 x = 2 ，则表达式 ( x + + )／3 的值是。

19、若x = 5，y = 10，则x y和x = y的逻辑值分别为和。

20、设有数组定义：int myintarray[] = { 10, 20, 30, 40, 50, 60, 70 };则执行以下几个语句后的输出结果是： 120。

《Java语言程序设计(基础篇)》(第10版梁勇著)第二十一章练习题答案

《Java语言程序设计（基础篇）》（第10版梁勇著）第二十一章练习题答案21.1import java.util.*;public class Exercise21_01 {public static void main(String[] args) {LinkedHashSet<String> set1 = new LinkedHashSet<String>(Arrays.asList( new String[]{"George", "Jim", "John", "Blake", "Kevin", "Michael"}));LinkedHashSet<String> set1Clone1 = (LinkedHashSet<String>)set1.clone(); LinkedHashSet<String> set1Clone2 = (LinkedHashSet<String>)set1.clone();LinkedHashSet<String> set2 = new LinkedHashSet<String>(Arrays.asList( new String[] {"George", "Katie", "Kevin", "Michelle", "Ryan"}));set1.addAll(set2);set1Clone1.removeAll(set2);set1Clone2.retainAll(set2);System.out.println("The union of the two sets is " + set1);System.out.println("The difference of the two sets is " + set1Clone1); System.out.println("The intersection of the two sets is " + set1Clone2); }}21.1附加import java.util.*;public class Exercise21_01Extra {public static void main(String[] args) {System.out.print("Enter a string: ");Scanner input = new Scanner(System.in);String s = input.nextLine();Character[] list1 = {'A', 'E', 'I', 'O', 'U'};Set<Character> vowels = new HashSet<>(Arrays.asList(list1));Set<Character> vowelsInString = new HashSet<>();Set<Character> consonantsInString = new HashSet<>();int numbeOfVowels = 0;int numbeOfConsonants = 0;for (int i = 0; i < s.length(); i++) {char ch = Character.toUpperCase(s.charAt(i));if (Character.isLetter(ch)) {if (vowels.contains(ch)) {if (!vowelsInString.contains(ch)) {vowelsInString.add(ch);numbeOfVowels++;}}else if (!consonantsInString.contains(ch)) {consonantsInString.add(ch);numbeOfConsonants++;}}}System.out.println("The number of vowels is " + numbeOfVowels);System.out.println("The number of consonants is " + numbeOfConsonants); }}21.2import java.util.*;import java.io.*;public class Exercise21_02 {public static void main(String[] args) {if (args.length != 1) {System.out.println("Usage: java Exercise21_02 fullfilename");System.exit(1);}String filename = args[0];// Create a tree set to hold the wordsTreeSet<String> treeSet = new TreeSet<String>();try {Scanner in = new Scanner(new File(filename));String line;while ((line = in.nextLine()) != null) {String[] tokens = line.split("[ |\n|\t|\r|.|,|)|(|-|\"]");for (int i = 0; i < tokens.length; i++)treeSet.add(tokens[i]);}}catch (Exception ex) {System.err.println(ex);}// Get an iterator for the setIterator iterator = treeSet.iterator();// Display mappingsSystem.out.println("\nDisplay words in ascending order ");while (iterator.hasNext()) {System.out.println(iterator.next());}}}21.3import java.util.*;import java.io.*;public class Exercise21_03 {public static void main(String[] args) {// Check usageif (args.length != 1) {System.out.println("Usage: java Exercise21_03 file.java");System.exit(1);}// Array of all Java keywords + true + nullString[] keywordString = {"abstract", "finally", "public", "boolean", "float", "return", "break", "for", "short", "byte","goto", "static", "case", "if", "super", "catch", "implements", "switch", "char", "import", "synchronized", "class","instanceof", "this", "const", "int", "throw", "continue","interface", "throws", "default", "long", "transient", "do","native", "try", "double", "new", "void", "else", "package","volatile", "extends", "private", "while", "final","protected", "true", "null"};Set<String> keywordSet =new HashSet<String>(Arrays.asList(keywordString));int count = 0;try {Scanner input = new Scanner(new File(args[0]));String text = "";while (input.hasNext()) {String line = input.nextLine();line = stripLineComments(line);line = stripLineStringLiterals(line);text += line + " ";}text = stripParagraghComments(text);String[] tokens = text.split("[ \\[,()\\]]");for (String token: tokens) {if (keywordSet.contains(token))count++;}System.out.println("The number of keywords in the program is " + count);}catch (Exception ex) {ex.printStackTrace();}}/* Strip line comments */private static String stripLineComments(String line) {int index = line.indexOf("//");if (index < 0)return line;elsereturn line.substring(0, index);}/* Strip string literals */private static String stripLineStringLiterals(String line) {int start = line.indexOf("\"");int end = line.indexOf("\"", start + 1);while (start > 0 && end > 0) {line = line.substring(0, start) + line.substring(end + 1);start = line.indexOf("\"");end = line.indexOf("\"");}return line;}/* Strip paragraph comments */private static String stripParagraghComments(String text) {int start = text.indexOf("/*");int end = text.indexOf("*/");while (start > 0 && end > 0) {text = text.substring(0, start) + text.substring(end + 2);start = text.indexOf("/*");end = text.indexOf("*/");}return text;}}/** This is an incorrect version. It does not count the case such as (this. Here the this keyword* is not counted. It does not exclude keywords in the comments*import java.util.*;import java.io.*;public class Exercise20_03 {public static void main(String[] args) {// Check usageif (args.length != 1) {System.out.println("Usage: java Exercise20_03 file.java");System.exit(0);}// Array of all Java keywords + true + nullString[] keywordString = {"abstract", "finally", "public","boolean", "float", "return", "break", "for", "short", "byte", "goto", "static", "case", "if", "super", "catch", "implements", "switch", "char", "import", "synchronized", "class","instanceof", "this", "const", "int", "throw", "continue","interface", "throws", "default", "long", "transient", "do","native", "try", "double", "new", "void", "else", "package","volatile", "extends", "private", "while", "final","protected", "true", "null"};Set<String> keywordSet =new HashSet<String>(Arrays.asList(keywordString));int count = 0;try {Scanner input = new Scanner(new File(args[0]));while (input.hasNext()) {String token = input.next();if (keywordSet.contains(token))count++;}System.out.println("The number of keywords in the program is " + count);}catch (Exception ex) {ex.printStackTrace();}}}*/21.4import java.util.Scanner;import java.util.HashSet;import java.util.Arrays;public class Exercise21_04 {public static void main(String[] args) throws Exception {HashSet<Character> set1 = new HashSet<Character>(Arrays.asList( new Character[]{'A', 'E', 'I', 'O', 'U'}));System.out.print("Enter a filename: ");Scanner input = new Scanner(System.in);String filename = input.nextLine();input = new Scanner(new java.io.File(filename));int countVowels = 0;int countConsonants = 0;while (input.hasNext()) {String s = input.nextLine().toUpperCase();for (int i = 0; i < s.length(); i++) {if (set1.contains(s.charAt(i)))countVowels++;else if (Character.isLetter(s.charAt(i)))countConsonants++;}}System.out.println("The number of vowels is " + countVowels + " and consonanats is " +countConsonants);}}21.5/*** Usage: Copy this class to the folder, run it with java JavaToHTMLftim * to generate* HTM file for all the .java file in this folder. The generated .htm files are* stored in the same folder*/import java.util.*;import java.io.*;public class Exercise21_05 {// Array of all Java keywords + true + false + nullstatic String[] keywordString = {"abstract", "assert", "boolean","break", "byte", "case", "catch", "char", "class", "const","continue", "default", "do", "double", "else", "enum","extends", "for", "final", "finally", "float", "goto", "if","implements", "import", "instanceof", "int", "interface","long", "native", "new", "package", "private", "protected","public", "return", "short", "static", "strictfp", "super","switch", "synchronized", "this", "throw", "throws","transient", "try", "void", "volatile", "while","true", "false", "null"};static Set<String> keywordSet =new HashSet<String>(Arrays.asList(keywordString));/** Main method */public static void main(String[] args) throws Exception {// Check usageif (args.length != 2) {System.out.println("Usage: java Exercise20_10 javaSourcefile htmlfile");System.exit(1);}Scanner input = new Scanner(new File(args[0]));PrintWriter output = new PrintWriter(new File(args[1]));JavaToHTML(input, output);}static boolean stringToken = false;static String inputFileName;public static void JavaToHTML(Scanner input, PrintWriter output) { try {output.format("%s\r\n", "<html>");output.format("%s\r\n", "<head>");output.format("%s\r\n","<title>Intro to Java Programming, 6E - " + inputFileName +"</title>");output.format("%s\r\n","<meta http-equiv=\"Content-Type\" content=\"text/html; charset=windows-1252\">");output.format("%s\r\n", "<style type = \"text/css\">");output.format("%s\r\n","body {font-family: \"Courier New\", sans-serif; font-size: 100%; color: black}");output.format("%s\r\n",".keyword {color: #000080; font-weight: bold}");output.format("%s\r\n", ".comment {color: #008000}");output.format("%s\r\n", ".literal {color: #0000ff}");// Match the color in the text// output.format("%s\r\n", ".keyword {color: black; font-weight: bold}");// output.format("%s\r\n", ".comment {color: #77797C}");// output.format("%s\r\n", ".literal {color: #007346; font-weight: bold}");output.format("%s\r\n", "</style>");output.format("%s\r\n", "</head>");output.format("%s\r\n", "<body>");output.format("%s\r\n", "<pre>");String text = "";String temp;// Read all lineswhile (input.hasNext()) {temp = input.nextLine();text += temp + "\r\n";}text = text.replaceAll(">", ">");text = text.replaceAll("<", "<");translateToHTML(text, input, output);output.format("%s\r\n", "</pre>");output.format("%s\r\n", "</body>");output.format("%s\r\n", "</html>");}catch (Exception ex) {System.out.println(ex);}finally {try {input.close();output.close();}catch (Exception ex) {}}}/** Translate Java source code to HTML */static void translateToHTML(String text, Scanner input, PrintWriter output) throws Exception {text = text.replaceAll("// ", "LINECOMMENT");text = text.replaceAll("/\\*", "BLOCKCOMMENT");String token;while (text != null && text.length() > 0) {// * and / are in conflict with /* and //String[] parts = text.split("[%\\+\\-\\*/\r\n\t \\[\\].;(){},]", 2); token = parts[0];if (token.length() > 1 && token.startsWith("LINECOMMENT")) {output.format("%s", "");parts = text.split("\r\n", 2);text = parts[1];output.format("%s", parts[0].replaceAll("LINECOMMENT", "// "));output.format("%s", "\r\n");continue;}else if (token.length() > 1 && token.startsWith("BLOCKCOMMENT")) {output.format("%s", "");parts = text.split("\\*/", 2);text = parts[1];output.format("%s", parts[0].replaceAll("BLOCKCOMMENT", "/*") +"*/");output.format("%s", "");continue;}else if (token.length() > 1 && token.matches("'\\w'*")) {output.format("%s", "");output.format("%s", token);output.format("%s", "");}else if (token.startsWith("\"") && token.endsWith("\"") &&(token.length() > 1)) {output.format("%s", "" + token+ "");}else if (token.startsWith("'") && token.endsWith("'") &&(token.length() > 1)) {output.format("%s", "" + token+ "");}else if (token.equals("' '")) {output.format("%s", "" + token+ "");}else if (token.startsWith("\"") && token.endsWith("\"") &&(token.length() == 1)) {if (stringToken) {output.format("%s", token + "");stringToken = false;}else {output.format("%s", "" + token); stringToken = true;}}else if (token.startsWith("\"")) {output.format("%s", "" + token); stringToken = true;}else if (token.endsWith("\"") && (!token.endsWith("\\\""))) { output.format("%s", token);output.format("%s", "");stringToken = false;}else if (token.matches("\\d+")) { // Check if numericoutput.format("%s", "" + token +"");}else if (!stringToken && keywordSet.contains(token)) {output.format("%s", "" + token +"");}else {output.format("%s", token);}if (token.length() < text.length()) {if (text.charAt(token.length()) == '<')output.format("%s", "<");else if (text.charAt(token.length()) == '>')output.format("%s", ">");elseoutput.format("%s", text.charAt(token.length()));}if (parts.length == 2) {text = parts[1];}}}}21.6import java.util.*;public class Exercise21_06 {public static void main(String[] args) {// Create a tree map to hold words and key and count as value TreeMap<Integer, Integer> treeMap = new TreeMap<>();Scanner input = new Scanner(System.in);while (true) {// Enter an integerSystem.out.print("Enter an integer: ");int number = input.nextInt();if (number == 0) break;Integer key = new Integer(number);if (treeMap.get(key) != null) {int value = ((Integer)treeMap.get(key)).intValue();value++;treeMap.put(key, new Integer(value));}else {treeMap.put(key, new Integer(1));}}Integer max = Collections.max(treeMap.values());Set<Integer> keys = treeMap.keySet();Iterator<Integer> iterator = keys.iterator();while (iterator.hasNext()) {Object key = iterator.next();Integer value = (Integer)(treeMap.get(key));if (value.equals(max)) {System.out.println("Number " + key + " occurred most");}}}}21.7import java.util.*;public class Exercise21_07 {public static void main(String[] args) {// Text in a stringString text = "Have a good day. Have a good class. " + "Have a good visit. Have fun!";// Create a hash map to hold words and key and count as value HashMap<String, Integer> hashMap = new HashMap<>();String[] tokens = text.split("[ |.|!|?]");for (String key: tokens) {if (hashMap.get(key) != null) {hashMap.put(key, hashMap.get(key).intValue() + 1);}else {if (key.trim().length() > 0)hashMap.put(key, 1);}}// Get an entry set for the tree mapSet<Map.Entry<String, Integer>> entrySet = hashMap.entrySet();ArrayList<WordOccurrence> list = new ArrayList<>();for (Map.Entry<String, Integer> entry: entrySet) {list.add(new WordOccurrence(entry.getKey(), entry.getValue())); }Collections.sort(list);for (WordOccurrence item: list) {System.out.println(item);}}}class WordOccurrence implements Comparable<WordOccurrence> {String word;int count;public WordOccurrence(String word, int count) {this.word = word;this.count = count;}@Overridepublic int compareTo(WordOccurrence o) {return count - o.count;}@Overridepublic boolean equals(Object o) {return word.equals(((WordOccurrence)o).word);}@Overridepublic String toString() {return word + ": " + count;}}21.8import java.util.*;import java.io.*;public class Exercise21_08 {public static void main(String[] args) {if (args.length != 1) {System.out.println("Usage: java Exercise21_08 fullfilename");System.exit(1);}String filename = args[0];// Create a tree map to hold words as key and count as valueTreeMap<String, Integer> treeMap = new TreeMap<String, Integer>();try {Scanner input = new Scanner(new File(filename));while (input.hasNext()) {String line = input.nextLine();String[] words = line.split("[ @!~{}\\[\\]$#^&*\n\t\r.,;?'\")(]");for (int i = 0; i < words.length; i++) {if (words[i].trim().length() > 0 &&words[i].trim().matches("[A-Z|a-z]+")) {String key = words[i].toLowerCase();if (treeMap.get(key) != null) {int count = treeMap.get(key);count++;treeMap.put(key, count);}else {treeMap.put(key, 1);}}}}}catch (Exception ex) {ex.printStackTrace();}// Get an entry set for the tree mapSet<Map.Entry<String, Integer>> entrySet = treeMap.entrySet();// Display words in alphabetical orderSystem.out.println("\nDisplay words and their count in " + " ascending order of the words");for (Map.Entry<String, Integer> entry: entrySet)System.out.println(entry.getValue() + "\t" + entry.getKey()); }}21.9import java.util.*;public class Exercise21_09 {public static void main(String[] args) {String[][] stateCapital = {{"Alabama", "Montgomery"},{"Alaska", "Juneau"},{"Arizona", "Phoenix"},{"Arkansas", "Little Rock"},{"California", "Sacramento"},{"Colorado", "Denver"},{"Connecticut", "Hartford"},{"Delaware", "Dover"},{"Florida", "Tallahassee"},{"Georgia", "Atlanta"},{"Hawaii", "Honolulu"},{"Idaho", "Boise"},{"Illinois", "Springfield"},{"Indiana", "Indianapolis"},{"Iowa", "Des Moines"},{"Kansas", "Topeka"},{"Kentucky", "Frankfort"},{"Louisiana", "Baton Rouge"},{"Maine", "Augusta"},{"Maryland", "Annapolis"},{"Massachusettes", "Boston"},{"Michigan", "Lansing"},{"Minnesota", "Saint Paul"},{"Mississippi", "Jackson"},{"Missouri", "Jefferson City"},{"Montana", "Helena"},{"Nebraska", "Lincoln"},{"Nevada", "Carson City"},{"New Hampshire", "Concord"},{"New Jersey", "Trenton"},{"New York", "Albany"},{"New Mexico", "Santa Fe"},{"North Carolina", "Raleigh"},{"North Dakota", "Bismark"},{"Ohio", "Columbus"},{"Oklahoma", "Oklahoma City"},{"Oregon", "Salem"},{"Pennslyvania", "Harrisburg"},{"Rhode Island", "Providence"},{"South Carolina", "Columbia"},{"South Dakota", "Pierre"},{"Tennessee", "Nashville"},{"Texas", "Austin"},{"Utah", "Salt Lake City"},{"Vermont", "Montpelier"},{"Virginia", "Richmond"},{"Washington", "Olympia"},{"West Virginia", "Charleston"},{"Wisconsin", "Madison"},{"Wyoming", "Cheyenne"}};Map<String, String> map = new HashMap<String, String>();for (int i = 0; i < stateCapital.length; i++)map.put(stateCapital[i][0].toLowerCase(), stateCapital[i][1]);Scanner input = new Scanner(System.in);System.out.print("Enter a state: ");String state = input.nextLine().toLowerCase().trim();if (map.containsKey(state))System.out.println("The capital is " +map.get(state));elseSystem.out.println("No such state ");}}21.10import java.util.*;import java.io.*;public class Exercise21_10 {public static void main(String[] args) {// Prompt the user to enter a Java source fileScanner input = new Scanner(System.in);System.out.print("Enter a file name: ");String filename = input.nextLine();// Array of all Java keywords + true + nullString[] keywordString = { "abstract", "finally", "public", "boolean", "float", "return", "break", "for", "short", "byte", "goto", "static","case", "if", "super", "catch", "implements", "switch", "char","import", "synchronized", "class", "instanceof", "this", "const","int", "throw", "continue", "interface", "throws", "default", "long","transient", "do", "native", "try", "double", "new", "void", "else","package", "volatile", "extends", "private", "while", "final","protected", "true", "null" };Set<String> keywordSet = newHashSet<String>(Arrays.asList(keywordString));int count = 0;try {input = new Scanner(new File(filename));String text = "";while (input.hasNext()) {String line = input.nextLine();line = stripLineComments(line);line = stripLineStringLiterals(line);text += line + " ";}text = stripParagraghComments(text);TreeMap<String, Integer> map = new TreeMap<String, Integer>();String[] tokens = text.split("[ \\[,()\\]]");for (String token : tokens) {if (keywordSet.contains(token))if (map.get(token) == null) {map.put(token, 1);} else {int value = map.get(token);value++;map.put(token, value);}}// Get all entries into a setSet<Map.Entry<String, Integer>> entrySet = map.entrySet();// Get key and value from each entryfor (Map.Entry<String, Integer> entry: entrySet)System.out.println(entry.getValue() + "\t" + entry.getKey()); } catch (Exception ex) {ex.printStackTrace();}}/* Strip line comments */private static String stripLineComments(String line) {int index = line.indexOf("//");if (index < 0)return line;elsereturn line.substring(0, index);}/* Strip string literals */private static String stripLineStringLiterals(String line) {int start = line.indexOf("\"");int end = line.indexOf("\"", start + 1);while (start > 0 && end > 0) {line = line.substring(0, start) + line.substring(end + 1);start = line.indexOf("\"");end = line.indexOf("\"");}return line;}/* Strip paragraph comments */private static String stripParagraghComments(String text) {int start = text.indexOf("/*");int end = text.indexOf("*/");while (start > 0 && end > 0) {text = text.substring(0, start) + text.substring(end + 2);start = text.indexOf("/*");。

java语言程序设计基础篇复习题答案

java语言程序设计基础篇复习题答案
Java语言程序设计基础篇复习题答案
在学习Java语言程序设计基础篇的过程中，复习题是一个很好的方式来巩固所学知识。

下面是一些常见问题的答案，希望能够帮助大家更好地复习和理解Java语言程序设计基础篇的知识。

1. 什么是Java语言的特点？
答：Java语言具有简单、面向对象、分布式、多线程、动态、解释性等特点。

2. Java语言有哪些基本数据类型？
答：Java语言的基本数据类型包括整型、浮点型、字符型、布尔型等。

3. 什么是Java语言中的变量？
答：变量是用来存储数据的内存空间，它具有数据类型和名称。

4. Java语言中的运算符有哪些？
答：Java语言中的运算符包括算术运算符、关系运算符、逻辑运算符、位运算符等。

5. 什么是Java语言中的控制语句？
答：控制语句用于控制程序的执行流程，包括顺序结构、选择结构、循环结构等。

6. 什么是Java语言中的数组？
答：数组是一种用来存储多个相同类型数据的数据结构。

7. Java语言中的方法是什么？
答：方法是一段用来完成特定任务的代码，它可以被重复使用。

8. 什么是Java语言中的类和对象？
答：类是一种模板，用来描述对象的属性和行为；对象是类的实例，具有特定的属性和行为。

通过复习这些问题的答案，我们可以更好地理解和掌握Java语言程序设计基础篇的知识，为以后的学习和实践打下坚实的基础。

希望大家在学习Java语言程序设计基础篇的过程中能够不断努力，取得更好的成绩。

《Java语言程序设计（基础篇）》（第10版梁勇著）第三章练习题答案

《Java语言程序设计（基础篇）》（第10版梁勇著）第三章练习题答案《Java语言程序设计（基础篇）》（第10版梁勇著）第三章练习题答案3.1public class Exercise03_01 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter a, b, c: ");double a = input.nextDouble();double b = input.nextDouble();double c = input.nextDouble();double discriminant = b * b - 4 * a * c;if (discriminant < 0) {System.out.println("The equation has no real roots");}else if (discriminant == 0) {double r1 = -b / (2 * a);System.out.println("The equation has one root " + r1);}else { // (discriminant > 0)double r1 = (-b + Math.pow(discriminant, 0.5)) / (2 * a);double r2 = (-b - Math.pow(discriminant, 0.5)) / (2 * a);System.out.println("The equation has two roots " + r1 + " and " + r2);}}}3.1附加public class Exercise03_01Extra {public static void main(String args[]) {Scanner input = new Scanner(System.in);System.out.print("Enter a numerator: ");int numerator = input.nextInt();System.out.print("Enter a denominator: ");int denominator = input.nextInt();if (numerator < denominator) {System.out.println(numerator + " / " + denominator + " is a proper fraction");}else if (numerator % denominator == 0) {System.out.print(numerator + " / " + denominator + " is an improper fraction ");System.out.println("and it can be reduced to " + numerator / denominator);}else {System.out.print(numerator + " / " + denominator + " is an improper fraction ");System.out.println("and its mixed fraction is " + numerator / denominator + " + " +numerator % denominator + " / " + denominator);}}}3.2public class Exercise03_02 {public static void main(String[] args) {Scanner input = new Scanner(System.in);int number1 = (int)(System.currentTimeMillis() % 10);int number2 = (int)(System.currentTimeMillis() * 7 % 10);int number3 = (int)(System.currentTimeMillis() * 3 % 10);System.out.print("What is " + number1 + " + " + number2 + " + " +number3 + "? ");int answer = input.nextInt();System.out.println(number1 + " + " + number2 + " + " + number3 +" = " + answer + " is " +(number1 + number2 + number3 == answer));}}3.2附加public class Exercise03_02Extra {public static void main(String args[]) {Scanner input = new Scanner(System.in);System.out.print("Enter the coordinates for two points: ");double x1 = input.nextDouble();double y1 = input.nextDouble();double x2 = input.nextDouble();double y2 = input.nextDouble();double m = (y2 - y1) / (x2 - x1);double b = y1 - m * x1;System.out.print("The line equation for two points (" + x1 + ", " + y1 + ") and (" + x2 + ", " + y2 + ") is " + "y = ");if (m == -1)System.out.print("-x");else if (m == 1)System.out.print("x");elseSystem.out.print(m + "x");if (b > 0)System.out.println(" + " + b);else if (b < 0)System.out.println(" - " + (-1 * b));else// b is 0System.out.println();}}3.3public class Exercise03_03 {public static void main(String[] args) {Scanner input = new Scanner(System.in); System.out.print("Enter a, b, c, d, e, f: ");double a = input.nextDouble();double b = input.nextDouble();double c = input.nextDouble();double d = input.nextDouble();double e = input.nextDouble();double f = input.nextDouble();double detA = a * d - b * c;if (detA == 0) {System.out.println("The equation has no solution"); }else {double x = (e * d - b * f) / detA;double y = (a * f- e * c) / detA;System.out.println("x is " + x + " and y is " + y);}}}3.3附加public class Exercise03_03Extra {public static void main(String[] args) {final double RADIUS = 5;double angle = Math.random() * 2 * Math.PI;double x = RADIUS * Math.random() * Math.cos(angle);double y = RADIUS * Math.sin(angle);double distance = Math.pow(x * x + y * y, 0.5);System.out.println("The point is (" + x + ", " + y + ") and its distance to the center is " + distance);}}3.4public class Exercise03_04 {public static void main(String[] args) {int number = (int)(Math.random() * 12) + 1;// or int number = (int)(System.currentTimeMillis() % 12 + 1);// or int number = (int)(Math.random() * 12) + 1;if (number == 1)System.out.println("Month is Januaray");else if (number == 2)System.out.println("Month is Feburary");else if (number == 3)System.out.println("Month is March");else if (number == 4)System.out.println("Month is April");else if (number == 5)System.out.println("Month is May");else if (number == 6)System.out.println("Month is June");else if (number == 7)System.out.println("Month is July");else if (number == 8)System.out.println("Month is August");else if (number == 9)System.out.println("Month is September");else if (number == 10)System.out.println("Month is October");else if (number == 11)System.out.println("Month is November");else// if (number == 12)System.out.println("Month is December");}}3.5public class Exercise03_05 {public static void main(String[] args) {java.util.Scanner input = new java.util.Scanner(System.in);// Prompt the user to enter an integer for todaySystem.out.print("Enter today抯 day: ");int today = input.nextInt();System.out.print("Enter the number of days elapsed since today: ");int elapsedDays = input.nextInt();String nameForToday;if (today == 0)nameForToday = "Sunday";else if (today == 1)nameForToday = "Monday";else if (today == 2)nameForToday = "Tuesday";else if (today == 3)nameForToday = "Wednesday";else if (today == 4)nameForToday = "Thursday";else if (today == 5)nameForToday = "Friday";else// if (today == 6)nameForToday = "Saturday";int futureDay = (today + elapsedDays) % 7; String nameForFutureDay;if (futureDay == 0)nameForFutureDay = "Sunday";else if (futureDay == 1) nameForFutureDay = "Monday";else if (futureDay == 2) nameForFutureDay = "Tuesday";else if (futureDay == 3) nameForFutureDay = "Wednesday";else if (futureDay == 4) nameForFutureDay = "Thursday";else if (futureDay == 5) nameForFutureDay = "Friday";else// if (futureDay == 6) nameForFutureDay = "Saturday";System.out.println("Today is " + nameForToday+ " and the future day is " + nameForFutureDay); } }3.6public class Exercise03_06 {public static void main(String[] args) {Scanner input = new Scanner(System.in);// Prompt the user to enter weight in pounds System.out.print("Enter weight in pounds: "); double weight = input.nextDouble();// Prompt the user to enter heightSystem.out.print("Enter feet: ");double feet = input.nextDouble();System.out.print("Enter inches: ");double inches = input.nextDouble();double height = feet * 12 + inches;// Compute BMIdouble bmi = weight * 0.45359237 / ((height * 0.0254) * (height * 0.0254));// Display resultSystem.out.println("BMI is " + bmi);if (bmi < 18.5)System.out.println("Underweight");else if (bmi < 25)System.out.println("Normal");else if (bmi < 30)System.out.println("Overweight");elseSystem.out.println("Obese");}}3.7/** Break down an amount into smaller units* Display the non-zero denominations only, and display singular* words for single units like 1 dollars, 1 penny, and display plural * words for more than one unit like 2 dollars, 3 pennies.*/public class Exercise03_07 {// Main methodpublic static void main(String[] args) {java.util.Scanner input = new java.util.Scanner(System.in);// Receive the amount entered from the keyboardSystem.out.print("Enter an amount in double, for example 11.56: ");double amount = input.nextDouble();int remainingAmount = (int)(amount * 100);// Find the number of one dollarsint numberOfOneDollars = remainingAmount / 100;remainingAmount = remainingAmount % 100;// Find the number of quarters in the remaining amountint numberOfQuarters = remainingAmount / 25;remainingAmount = remainingAmount % 25;// Find the number of dimes in the remaining amountint numberOfDimes = remainingAmount / 10;remainingAmount = remainingAmount % 10;// Find the number of nickels in the remaining amountint numberOfNickels = remainingAmount / 5;remainingAmount = remainingAmount % 5;// Find the number of pennies in the remaining amountint numberOfPennies = remainingAmount;// Display resultsif (amount < 0) {System.out.println("Your amount is negative");System.exit(1);}else if (amount < 0) {System.out.println("Your amount is zero");System.exit(2);}System.out.println("Your amount " + amount + " consists of ");if (numberOfOneDollars > 1)System.out.println(numberOfOneDollars + "\ dollars");else if (numberOfOneDollars == 1)System.out.println(numberOfOneDollars + "\ dollar");if (numberOfQuarters > 1)System.out.println(numberOfQuarters + "\ quarters");else if (numberOfQuarters == 1)System.out.println(numberOfQuarters + "\ quarter");if (numberOfDimes > 1)System.out.println(numberOfDimes + "\ dimes");else if (numberOfDimes == 1)System.out.println(numberOfDimes + "\ dime");if (numberOfNickels > 1)System.out.println(numberOfNickels + "\ nickels");else if (numberOfNickels == 1)System.out.println(numberOfNickels + "\ nickel");if (numberOfPennies > 1)System.out.println(numberOfPennies + "\ pennies");else if (numberOfPennies == 1)System.out.println(numberOfPennies + "\ penny");}}3.8public class Exercise03_08 {public static void main(String[] args) {java.util.Scanner input = new java.util.Scanner(System.in); // Enter three numbersSystem.out.print("Enter three integers: ");int number1 = input.nextInt();int number2 = input.nextInt();int number3 = input.nextInt();if (number1 > number2) {int temp = number1;number1 = number2;number2 = temp;}if (number2 > number3) {int temp = number2;number2 = number3;number3 = temp;}if (number1 > number2) {int temp = number1;number1 = number2;number2 = temp;}System.out.println("The sorted numbers are "+ number1 + " " + number2 + " " + number3);}}public class Exercise03_09 {public static void main(String[] args) {Scanner input = new Scanner(System.in);// Prompt the user to enter an integerSystem.out.print("Enter the first 9 digits of an ISBN as integer: ");int number = input.nextInt();// Calculate checksum (You may write a loop to simplify it in Ch4int checksum =((number / 100000000 % 10) * 1 +(number / 10000000 % 10) * 2 +(number / 1000000 % 10) * 3 +(number / 100000 % 10) * 4 +(number / 10000 % 10) * 5 +(number / 1000 % 10) * 6 +(number / 100 % 10) * 7 +(number / 10 % 10) * 8 +(number % 10) * 9) % 11;System.out.print("The ISBN-10 number is ");// Display leading zeros, improve the solution using loops in the next chapterif (number / 100000000 == 0) {System.out.print("0");if (number / 10000000 == 0) {System.out.print("0");if (number / 1000000 == 0) {System.out.print("0");if (number / 100000 == 0) {System.out.print("0");if (number / 10000 == 0) { System.out.print("0");if (number / 1000 == 0) { System.out.print("0");if (number / 100 == 0) {System.out.print("0");if (number / 10 == 0) {System.out.print("0");if (number == 0) {System.out.print("0");}}}}}}}}}System.out.print(number);if (checksum == 10)System.out.print("X");elseSystem.out.print(checksum);}}3.10public class Exercise03_10 {public static void main(String[] args) {// 1. Generate two random single-digit integersint number1 = (int)(Math.random() * 10);int number2 = (int)(Math.random() * 10);// 2. Prompt the student to answer 搘hat is number1 + number2?? System.out.print("What is " + number1 + " + " + number2 + "? "); Scanner input = new Scanner(System.in);int answer = input.nextInt();// 4. Grade the answer and display the resultString replyString;if (number1 + number2 == answer)replyString = "You are correct!";elsereplyString = "Your answer is wrong.\" + number1 + " + "+ number2 + " should be " + (number1 + number2);System.out.println(replyString);}}3.11public class Exercise03_11 {public static void main(String[] args) {java.util.Scanner input = new java.util.Scanner(System.in);// Prompt the user to enter inputSystem.out.print("Enter a month in the year (e.g., 1 for Jan): ");int month = input.nextInt();System.out.print("Enter a year: ");int year = input.nextInt();int numberOfDaysInMonth = 0;switch (month) {case 1:System.out.print("January " + year);numberOfDaysInMonth = 31;break;case 2:System.out.print("February " + year);if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) { numberOfDaysInMonth = 29;}else {numberOfDaysInMonth = 28;}break;case 3:System.out.print("March " + year);numberOfDaysInMonth = 31;break;case 4:System.out.print("April " + year);numberOfDaysInMonth = 30;break;case 5:System.out.print("May " + year);numberOfDaysInMonth = 31;break;case 6:System.out.print("June " + year);numberOfDaysInMonth = 30;break;case 7:System.out.print("July " + year);numberOfDaysInMonth = 31;break;case 8:System.out.print("August " + year);numberOfDaysInMonth = 31;break;case 9:System.out.print("September " + year);numberOfDaysInMonth = 30;break;case 10:System.out.print("October " + year);numberOfDaysInMonth = 31;break;case 11:System.out.print("November " + year);numberOfDaysInMonth = 30;break;case 12:System.out.print("December " + year);numberOfDaysInMonth = 31;break;}System.out.print(" has " + numberOfDaysInMonth + " days"); }}3.12public class Exercise03_12 {public static void main(String[] args) {Scanner input = new Scanner(System.in);System.out.print("Enter a three-digit integer: ");int number = input.nextInt();if (number / 100 == number % 10)System.out.println(number + " is a palindrome");elseSystem.out.println(number + " is not a palindrome");}}3.13public class Exercise03_13 {public static void main(String[] args) {java.util.Scanner input = new java.util.Scanner(System.in);// Prompt the user to enter filing statusSystem.out.print("(0-single filer, 1-married jointly or qualifying widow(er),"+ "\2-married separately, 3-head of household)\" + "Enter the filing status: ");int status = input.nextInt();// Prompt the user to enter taxable incomeSystem.out.print("Enter the taxable income: ");double income = input.nextDouble();// Compute taxdouble tax = 0;if (status == 0) { // Compute tax for single filersif (income <= 8350) {tax = income * 0.10;} else if (income <= 33950) {tax = 8350 * 0.10 + (income - 8350) * 0.15;} else if (income <= 82250) {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (income - 33950)* 0.25; } else if (income <= 171550) {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (82250 - 33950) * 0.25 + (income - 82250) * 0.28;} else if (income <= 372950) {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (82250 - 33950) * 0.25 + (171550 - 82250) * 0.28 + (income - 171550) * 0.33;} else {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (82250 - 33950) * 0.25 + (171550 - 82250) * 0.28 + (372950 - 171550) * 0.33 + (income - 372950) * 0.35;}} else if (status == 1) { // Compute tax for married file jointly if (income <= 16700) {tax = income * 0.10;} else if (income <= 67900) {tax = 16700 * 0.10 + (income - 16700) * 0.15;} else if (income <= 137050) {tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (income - 67900) * 0.25; } else if (income <= 208850) {tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (137050 - 67900) * 0.25 + (income - 137050) * 0.28;} else if (income <= 372950) {tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (137050 - 67900) * 0.25 + (208850 - 137050) * 0.28 + (income - 208850) * 0.33;} else {tax = 16700 * 0.10 + (67900 - 16700) * 0.15 + (137050 - 67900) * 0.25 + (171950 - 137050) * 0.28 + (372950 - 208850) * 0.33+ (income - 372950) * 0.35;}} else if (status == 2) { // Compute tax for married separately if (income <= 8350) {tax = income * 0.10;} else if (income <= 33950) {tax = 8350 * 0.10 + (income - 8350) * 0.15;} else if (income <= 68525) {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (income - 33950) * 0.25; } else if (income <= 104425) {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (68525 - 33950) * 0.25 + (income - 68525) * 0.28;} else if (income <= 186475) {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (68525 - 33950) * 0.25 + (104425 - 68525) * 0.28 + (income - 104425) * 0.33;} else {tax = 8350 * 0.10 + (33950 - 8350) * 0.15 + (68525 - 33950) * 0.25 + (104425 - 68525) * 0.28 + (186475 - 104425) * 0.33 + (income - 186475) * 0.35;}} else if (status == 3) { // Compute tax for head of household if (income <= 11950) {tax = income * 0.10;} else if (income <= 45500) {tax = 11950 * 0.10 + (income - 11950) * 0.15;} else if (income <= 117450) {tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (income - 45500) * 0.25; } else if (income <= 190200) {tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (117450 - 45500) * 0.25 + (income - 117450) * 0.28;} else if (income <= 372950) {tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (117450 - 45500) * 0.25 + (190200 - 117450) * 0.28 + (income - 190200) * 0.33;} else {tax = 11950 * 0.10 + (45500 - 11950) * 0.15 + (117450 - 45500) * 0.25 + (190200 - 117450) * 0.28 + (372950 - 190200) * 0.33+ (income - 372950) * 0.35;}} else {System.out.println("Error: Wrong filing status");System.exit(1);}// Display the resultSystem.out.println("Tax is " + (int) (tax * 100) / 100.0);}}3.14public class Exercise03_14 {public static void main(String[] args) {// Obtain the random number 0 or 1int number = (int)(Math.random() * 2);// Prompt the user to enter a guessjava.util.Scanner input = new java.util.Scanner(System.in);System.out.print("Guess head or tail? " +"Enter 0 for head and 1 for tail: ");int guess = input.nextInt();// Check the guessif (guess == number)System.out.println("Correct guess");else if (number == 0)System.out.println("Sorry, it is a head");elseSystem.out.println("Sorry, it is a tail");}}3.15public class Exercise03_15 {public static void main(String[] args) {// Generate a lotteryint lottery = (int)(Math.random() * 1000);// Prompt the user to enter a guessjava.util.Scanner input = new java.util.Scanner(System.in); System.out.print("Enter your lottery pick (three digits): ");int guess = input.nextInt();// Get digitsint l1 = lottery / 100;int l2 = (lottery % 100) / 10; // l2 = (lottery / 10) % 10int l3 = lottery % 10;int g1 = guess / 100;int g2 = (guess % 100) / 10;int g3 = guess % 10;System.out.println("Lottery is " + lottery);// Check the guessif (guess == lottery)System.out.println("Exact match: you win $10,000");else if (g1 == l1 && g3 == l2 && g2 == l3 ||g2 == l1 && g1 == l2 && g3 == l3 ||g2 == l1 && g3 == l2 && g1 == l3 ||g3 == l1 && g1 == l2 && g2 == l3 ||g3 == l1 && g2 == l2 && g1 == l3)System.out.println("Match all digits: you win $3,000"); else if (g1 == l1 || g1 == l2 || g1 == l3 ||g2 == l1 || g2 == l2 || g2 == l3 ||g3 == l1 || g3 == l2 || g3 == l3)System.out.println("Match one digit: you win $1,000"); elseSystem.out.println("Sorry, no match");}}3.16public class Exercise03_16 {public static void main(String[] args) {double x = Math.random() * 100 - 50;double y = Math.random() * 200 - 100;System.out.println(x + ", " + y);}}3.17public class Exercise03_17 {public static void main(String[] args) {// Generate scissor, rock, paperint computerNumber = (int)(Math.random() * 3);// Prompt the user to enter scissor, rock, or paper java.util.Scanner input = new java.util.Scanner(System.in); System.out.print("scissor (0), rock (1), paper (2): ");int userNumber = input.nextInt();// Check the guessswitch (computerNumber) {case 0:if (userNumber == 0)System.out.print("The computer is scissor. You are scissor too. It is a draw");else if (userNumber == 1)System.out.print("The computer is scissor. You are rock. You won");else if (userNumber == 2)System.out.print("The computer is scissor. You are paper. You lost");break;case 1:if (userNumber == 0)System.out.print("The computer is rock. You are scissor. You lost");else if (userNumber == 1)System.out.print("The computer is rock. You are rock too. It is a draw");else if (userNumber == 2)System.out.print("The computer is rock. You are paper. You won");break;case 2:if (userNumber == 0)System.out.print("The computer is paper. You are scissor. You won");else if (userNumber == 1)System.out.print("The computer is paper. You are rock. You lost");else if (userNumber == 2)System.out.print("The computer is paper. You are paper too.It is a draw");break;}}}3.18public class Exercise03_18 {public static void main(String args[]) {Scanner input = new Scanner(System.in);System.out.print("Enter package weight: ");double w = input.nextDouble();if (w <= 1) {System.out.println("The shipping cost is $3.5");}else if (w <= 3) {System.out.println("The shipping cost is $5.5");}else if (w <= 10) {System.out.println("The shipping cost is $8.5");}else if (w <= 20) {System.out.println("The shipping cost is $10.5");}else {System.out.println("The package cannot be shipped");}}}3.19public class Exercise03_19 {public static void main(String[] args) {java.util.Scanner input = new java.util.Scanner(System.in); // Enter three edgesSystem.out.print("Enter three edges (length in double): ");double edge1 = input.nextDouble();double edge2 = input.nextDouble();double edge3 = input.nextDouble();。

java基础习题及答案

程序设计—基础篇习题1.作图.2. 输出101--500之间的所有奇数,奇数之和.3. 输出100--200间不能被3整除的数.4. 输入初值,输出100个不能被3整除的数.5. 求S=1+(1+2)+(1+2+3)+...+(1+2+3+...+n)的值.6. 设S=1*2*3*...*n,求S不大于400000时的最大n.7. 设S=11*22*33*...*n n,求S不大于400000时的最大n.8. 找出1~1000间的全部”同构数”.如果一个数出现在其平方数右端,则称此数为同构数,如1在12=1的右端,5在52=25的右端,25在252=625的右端等.9. 百鸡问题。

“鸡翁一,值钱五,鸡母一,值钱三,鸡雏三,值钱一,百钱买百鸡,问鸡翁、鸡母、鸡雏各几何？”10.利用一维数组,统计一个班学生0-9,10-19,..90-99及100各分数段的人数.11.插入法排序.排序方法:设有10个数存放在数组A中,分别用A[1],A[2],..,A[10]表示.先将A[1]与A[2]比较,若A[2]<A[1],则交值这两个元素的值,A[1],A[2]顺序排列.再将A[3]与A[1],A[2]比较,按照顺序确定A[3]应放的位置,A[1],A[2],A[1]顺序排列.依次将后面的数一个一个拿来插入排好序的数列中,直到所有的数按顺序排好.12．2个按升序(从小到大)排列的数列A[1],A[2],....,A[N]和B[1],B[2],...,B[M]中各元素按其大小关系存放到数组c.同时必须注意对数组A或B残余元素的的追加处理。

13．运动员成绩排名.设有一表格记录了10人参加的男子100M决赛成绩,运动员号码和成绩自行确定,设计一程序,将给定的成绩排名输出。

14．知某班学生M(M<100)人,其N(N<4)门课程.度按平均成绩输出学生平均成绩名次表(要求每个学生的信息包括:名次,学号(用整型数),平均成绩等)。

C++程序设计Y.Daniel Liang 第十七章课后习题答案

#include <iostream>#include <string>#include <cmath>#include "Queue.h"using namespace std;#ifndef BINARYTREE_H#define BINARYTREE_Htemplate < typename T >class TreeNode{public:T element; // Element contained in the node TreeNode < T > * left; // Pointer to the left child TreeNode < T > * right; // Pointer to the right childTreeNode() // No-arg constructor{left = NULL;next = NULL;}TreeNode(T element) // Constructor{this->element = element;left = NULL;right = NULL;}};template < typename T >class BinaryTree{public:BinaryTree();BinaryTree(T elements[], int arraySize);bool insert(T element);void inorder();void preorder();void postorder();bool search(T element);void breadthFirstTraversal();int depth();private:TreeNode < T > * root;int size;void inorder(TreeNode < T > * root);void postorder(TreeNode < T > * root);void preorder(TreeNode < T > * root);bool search(T element, TreeNode < T > * root);int depth(TreeNode<T> * root);};template < typename T >BinaryTree < T >::BinaryTree(){root = NULL;size = 0;}template < typename T >BinaryTree < T >::BinaryTree(T elements[], int arraySize){root = NULL;size = 0;for (int i = 0; i < arraySize; i++){insert(elements[i]);}}/* Insert element into the binary tree * Return true if the element is inserted successfully * Return false if the element is already in the list */template < typename T >bool BinaryTree < T >::insert(T element){if (root == NULL)root = new TreeNode < T > (element); // Create a new rootelse{// Locate the parent nodeTreeNode < T > * parent = NULL;TreeNode < T > * current = root;while (current != NULL)if (element < current->element){parent = current;current = current->left;}else if (element > current->element){parent = current;current = current->right;}elsereturn false; // Duplicate node not inserted// Create the new node and attach it to the parent node if (element < parent->element)parent->left = new TreeNode < T > (element);elseparent->right = new TreeNode < T > (element);}size++;return true; // Element inserted}/* Inorder traversal */template < typename T >void BinaryTree < T >::inorder(){inorder(root);}/* Inorder traversal from a subtree */template < typename T >void BinaryTree < T >::inorder(TreeNode < T > * root){if (root == NULL) return;inorder(root->left);cout << root->element << " ";inorder(root->right);}/* Postorder traversal */template < typename T >void BinaryTree < T >::postorder(){postorder(root);}/** Inorder traversal from a subtree */template < typename T >void BinaryTree < T >::postorder(TreeNode < T > * root) {if (root == NULL) return;postorder(root->left);postorder(root->right);cout << root->element << " ";}/* Preorder traversal */template < typename T >void BinaryTree < T >::preorder(){preorder(root);}/* Preorder traversal from a subtree */template < typename T >void BinaryTree < T >::preorder(TreeNode < T > * root) {if (root == NULL) return;cout << root->element << " ";preorder(root->left);preorder(root->right);}/* Get the number of nodes in the tree */template < typename T >int BinaryTree < T >::getSize(){return size;}template < typename T >void BinaryTree < T >::breadthFirstTraversal() {Queue<TreeNode<T> *> queue;if (root != NULL) queue.enqueue(root);while (queue.getSize() > 0){TreeNode<T> * node = queue.dequeue();cout << node->element << " ";if ( (node->left) != NULL)queue.enqueue(node->left);if ( (node->right) != NULL)queue.enqueue(node->right);}}#endifint main(){BinaryTree < string > tree1;tree1.insert("George");tree1.insert("Michael");tree1.insert("Tom");tree1.insert("Adam");tree1.insert("Jones");tree1.insert("Peter");tree1.insert("Daniel");cout << "Inorder (sorted): ";tree1.inorder();cout << "\nPostorder: ";tree1.postorder();cout << "\nPreorder: ";tree1.preorder();cout << "\nThe number of nodes is " << tree1.getSize();int numbers[] ={2, 4, 3, 1, 8, 5, 6, 7};BinaryTree < int > tree2(numbers, 8);cout << "\nInorder (sorted): ";tree2.inorder();// Test breadth-firstcout << "\nBreadth-first: ";tree2.breadthFirstTraversal();return 0;}Exercise17_4#include <iostream>#include <string>#include "GenericStack.h"#include "LinkedList.h"using namespace std;#ifndef BINARYTREE_H#define BINARYTREE_Htemplate < typename T >class TreeNode{public:T element; // Element contained in the node TreeNode < T > * left; // Pointer to the left child TreeNode < T > * right; // Pointer to the right childTreeNode() // No-arg constructor{left = NULL;next = NULL;}TreeNode(T element) // Constructor{this->element = element;left = NULL;right = NULL;}};template < typename T >class BinaryTree{public:BinaryTree();BinaryTree(T elements[], int arraySize);bool insert(T element);void inorder();void preorder();void postorder();int getSize();bool search(T element);void breadthFirstTraversal();int depth();private:TreeNode < T > * root;int size;void inorder(TreeNode < T > * root);void postorder(TreeNode < T > * root);void preorder(TreeNode < T > * root);bool search(T element, TreeNode < T > * root);int depth(TreeNode<T> * root);};template < typename T >BinaryTree < T >::BinaryTree(){root = NULL;size = 0;}template < typename T >BinaryTree < T >::BinaryTree(T elements[], int arraySize) {root = NULL;size = 0;for (int i = 0; i < arraySize; i++){insert(elements[i]);}}/* Insert element into the binary tree * Return true if the element is inserted successfully * Return false if the element is already in the list */template < typename T >bool BinaryTree < T >::insert(T element){if (root == NULL)root = new TreeNode < T > (element); // Create a new rootelse{// Locate the parent nodeTreeNode < T > * parent = NULL;TreeNode < T > * current = root;while (current != NULL)if (element < current->element){parent = current;current = current->left;}else if (element > current->element){parent = current;current = current->right;}elsereturn false; // Duplicate node not inserted// Create the new node and attach it to the parent nodeif (element < parent->element)parent->left = new TreeNode < T > (element);elseparent->right = new TreeNode < T > (element);}size++;return true; // Element inserted}/* Inorder traversal */template < typename T >void BinaryTree < T >::inorder(){inorder(root);}/* Inorder traversal from a subtree */template < typename T >void BinaryTree < T >::inorder(TreeNode < T > * root){if (root == NULL) return;Stack<TreeNode<T> *> stack;stack.push(root);LinkedList<TreeNode<T> *> processedList;while (!stack.isEmpty()){TreeNode<T> * node = stack.peek();if (node->left != NULL && !processedList.contains(node->left))stack.push(node->left);else{cout << node->element << " ";processedList.add(node);stack.pop();if (node->right != NULL)stack.push(node->right);}}}/* Get the number of nodes in the tree */template < typename T >int BinaryTree < T >::getSize(){return size;#endifint main(){BinaryTree < string > tree1;tree1.insert("George");tree1.insert("Michael");tree1.insert("Tom");tree1.insert("Adam");tree1.insert("Jones");tree1.insert("Peter");tree1.insert("Daniel");cout << "Inorder (sorted): ";tree1.inorder();cout << "\nThe number of nodes is " << tree1.getSize();int numbers[] ={2, 4, 3, 1, 8, 5, 6, 7};BinaryTree < int > tree2(numbers, 8);cout << "\nInorder (sorted): ";tree2.inorder();return 0;}Exercise17_6#include <iostream>#include <string>#include "GenericStack.h"#include "LinkedList.h"using namespace std;#ifndef BINARYTREE_H#define BINARYTREE_Htemplate < typename T >class TreeNode{public:T element; // Element contained in the node TreeNode < T > * left; // Pointer to the left child TreeNode < T > * right; // Pointer to the right childTreeNode() // No-arg constructor{left = NULL;next = NULL;}TreeNode(T element) // Constructor{this->element = element;left = NULL;right = NULL;}};template < typename T >class BinaryTree{public:BinaryTree();BinaryTree(T elements[], int arraySize);bool insert(T element);void inorder();void preorder();void postorder();int getSize();bool search(T element);void breadthFirstTraversal();int depth();private:TreeNode < T > * root;int size;void inorder(TreeNode < T > * root);void postorder(TreeNode < T > * root);void preorder(TreeNode < T > * root);bool search(T element, TreeNode < T > * root); int depth(TreeNode<T> * root);};template < typename T >BinaryTree < T >::BinaryTree(){root = NULL;size = 0;}template < typename T >BinaryTree < T >::BinaryTree(T elements[], int arraySize){root = NULL;size = 0;for (int i = 0; i < arraySize; i++){insert(elements[i]);}}/* Insert element into the binary tree * Return true if the element is inserted successfully * Return false if the element is already in the list */template < typename T >bool BinaryTree < T >::insert(T element){if (root == NULL)root = new TreeNode < T > (element); // Create a new rootelse{// Locate the parent nodeTreeNode < T > * parent = NULL;TreeNode < T > * current = root;while (current != NULL)if (element < current->element){parent = current;current = current->left;}else if (element > current->element){parent = current;current = current->right;}elsereturn false; // Duplicate node not inserted// Create the new node and attach it to the parent node if (element < parent->element)parent->left = new TreeNode < T > (element);elseparent->right = new TreeNode < T > (element);}size++;return true; // Element inserted}/* Postorder traversal */template < typename T >void BinaryTree < T >::postorder(){postorder(root);}/** Inorder traversal from a subtree */template < typename T >void BinaryTree < T >::postorder(TreeNode < T > * root) {if (root == NULL) return;Stack<TreeNode<T> *> stack;stack.push(root);LinkedList<TreeNode<T> *> processedList;while (!stack.isEmpty()){TreeNode<T> * node = stack.peek();if (processedList.contains(node)){cout << node->element << " ";stack.pop();}else{processedList.add(node);if (node->right != NULL)stack.push(node->right);if (node->left != NULL)stack.push(node->left);}}}/* Get the number of nodes in the tree */template < typename T >int BinaryTree < T >::getSize(){return size;}#endifint main(){BinaryTree < string > tree1;tree1.insert("George");tree1.insert("Michael");tree1.insert("Tom");tree1.insert("Adam");tree1.insert("Jones");tree1.insert("Peter");tree1.insert("Daniel");// cout << "Inorder (sorted): ";// tree1.inorder();cout << "\nPostorder: ";tree1.postorder();// cout << "\nPreorder: ";// tree1.preorder();cout << "\nThe number of nodes is " << tree1.getSize();return 0;}Exercise17_8#include <iostream>#include <string>#include "Heap.h"using namespace std;template < typename T >void sort(T list[], int arraySize) {Heap < T > heap;for (int i = 0; i < arraySize; i++) {heap.add(list[i]);}for (int i = 0; i < arraySize; i++) {list[i] = heap.remove();}}int main(){int numbers[] ={8, 9, 2, 3, 4, 1, 5, 6, 7};sort(numbers, 9);for (int i = 0; i < 9; i++)cout << numbers[i] << " ";return 0;}。

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《Java语言程序设计（基础篇）》（第10版梁勇著）第十七章练习题答案17.1import java.io.*;import java.util.*;public class Exercise17_01 {public static void main(String[] args) throws IOException {try (Formatter output =new Formatter(new FileOutputStream("Exercise17_01.txt", true)); ) {for (int i = 0; i < 100; i++)output.format("%d", (int)(Math.random() * 100000));}}}17.2import java.io.*;public class Exercise17_02 {public static void main(String[] args) throws IOException {try (DataOutputStream output =new DataOutputStream(new FileOutputStream("Exercise17_02.dat", true));) {for (int i = 0; i < 100; i++)output.writeInt((int)(Math.random() * 100000));}System.out.println("Done");}}17.3import java.io.*;public class Exercise17_03 {/** Main method */public static void main(String[] args) {// Read dataint count = 0;try ( // Declare and create data input and output streamsDataInputStream dis =new DataInputStream(new FileInputStream("Exercise17_03.dat"));) {int total = 0;while (dis.available() > 0) {int temp = dis.readInt();total += temp;count++;System.out.print(temp + " ");}System.out.println("\nCount is " + count);System.out.println("\nTotal is " + total);}catch (FileNotFoundException ex) {System.out.println("File not found");}catch (IOException ex) {System.out.println(ex.getMessage());}}}17.4import java.io.*;public class Exercise17_04 {public static void main(String[] args) throws IOException {try (BufferedReader input = new BufferedReader(new FileReader(args[0])); DataOutputStream output = new DataOutputStream(newFileOutputStream(args[1]));) {String line;while ((line = input.readLine()) != null)output.writeUTF(line);}try (InputStream input1 = new FileInputStream(args[0]);InputStream input2 = new FileInputStream(args[1]);) {System.out.println(args[0] + "'s size is " + input1.available() + " bytes");System.out.println(args[1] + "'s size is " + input2.available() + " bytes");}}}17.5import java.io.*;public class Exercise17_05 {public static void main(String[] args) throws IOException {try (ObjectOutputStream output = new ObjectOutputStream(new FileOutputStream("Exercise17_05.dat"));) {output.writeObject(new int[]{1, 2, 3, 4, 5});output.writeObject(new java.util.Date());output.writeDouble(5.5);}}}17.6import java.io.*;public class Exercise17_06 {public static void main(String[] args) throws IOException {try (ObjectOutputStream output = new ObjectOutputStream(new FileOutputStream("Exercise17_06.dat"));) {output.writeObject(new Loan(2.5, 5, 1000));output.writeObject(new Loan(3.5, 5, 2000));output.writeObject(new Loan(4.5, 5, 3000));output.writeObject(new Loan(5.5, 5, 4000));output.writeObject(new Loan(6.5, 5, 5000));}}}17.7import java.io.*;public class Exercise17_07 {public static void main(String[] args) {int total = 0;int count = 0;try (ObjectInputStream input = new ObjectInputStream(new BufferedInputStream( new FileInputStream("Exercise17_07.dat")));) {while (true) {Loan loan = (Loan)(input.readObject());total += loan.getLoanAmount();count++;}}catch (EOFException ex) {System.out.println("Number of loan objects is " + count);System.out.println("Total loan amount is " + total);}catch (Exception ex) {ex.printStackTrace();}}}17.8import java.io.*;public class Exercise17_08 {public static void main(String[] args) throws IOException {try (RandomAccessFile raf = new RandomAccessFile("Exercise17_08.dat", "rw"); ) {int count = 0;if (raf.length() > 0)count = raf.readInt();raf.seek(0);raf.writeInt(++count);System.out.println("Current count is " + count);}}}17.9import java.io.*;import javafx.application.Application;import javafx.geometry.Pos;import javafx.scene.Scene;import javafx.scene.control.Button;import bel;import javafx.scene.control.TextField;import yout.BorderPane;import yout.GridPane;import yout.HBox;import javafx.stage.Stage;public class Exercise17_09 extends Application {// Specify the size of five string fields in the recordfinal static int NAME_SIZE = 32;final static int STREET_SIZE = 32;final static int CITY_SIZE = 20;final static int STATE_SIZE = 2;final static int ZIP_SIZE = 5;final static int RECORD_SIZE =(NAME_SIZE + STREET_SIZE + CITY_SIZE + STATE_SIZE + ZIP_SIZE);// Access address.dat using RandomAccessFileprivate RandomAccessFile raf;// Text fieldsprivate TextField tfName = new TextField();private TextField tfStreet = new TextField();private TextField tfCity = new TextField();private TextField tfState = new TextField();private TextField tfZip = new TextField();// Buttonsprivate Button btAdd = new Button("Add");private Button btFirst = new Button("First");private Button btNext = new Button("Next");private Button btPrevious = new Button("Previous");private Button btLast = new Button("Last");private Button btUpdate = new Button("Update");public Exercise17_09() {// Open or create a random access filetry {raf = new RandomAccessFile("address.dat", "rw");}catch(IOException ex) {ex.printStackTrace();System.exit(1);}}@Overridepublic void start(Stage primaryStage) {tfState.setPrefColumnCount(2);tfZip.setPrefColumnCount(4);tfCity.setPrefColumnCount(12);// Pane p1 for holding labels Name, Street, and CityGridPane p1 = new GridPane();p1.setAlignment(Pos.CENTER);p1.setHgap(5);p1.setVgap(5);p1.add(new Label("Name"), 0, 0);p1.add(new Label("Street"), 0, 1);p1.add(new Label("City"), 0, 2);p1.add(tfName, 1, 0);p1.add(tfStreet, 1, 1);HBox p2 = new HBox(5);p2.getChildren().addAll(tfCity, new Label("State"), tfState, new Label("Zip"), tfZip);p1.add(p2, 1, 2);// Add buttons to a paneHBox p3 = new HBox(5);p3.getChildren().addAll(btAdd, btFirst, btNext, btPrevious, btLast, btUpdate);p3.setAlignment(Pos.CENTER);// Add p1 and p3 to a border paneBorderPane borderPane = new BorderPane();borderPane.setCenter(p1);borderPane.setBottom(p3);// Create a scene and place it in the stageScene scene = new Scene(borderPane, 400, 120);primaryStage.setTitle("Exercise17_09"); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stage// Display the first record if existstry {if (raf.length() > 0) readAddress(0);}catch (IOException ex) {ex.printStackTrace();}btAdd.setOnAction(e -> {try {writeAddress(raf.length());}catch (Exception ex) {}});btFirst.setOnAction(e -> {try {if (raf.length() > 0) readAddress(0);}catch (IOException ex) {}});btNext.setOnAction(e -> {try {long currentPosition = raf.getFilePointer();if (currentPosition < raf.length())readAddress(currentPosition);}catch (IOException ex) {}});btPrevious.setOnAction(e -> {try {long currentPosition = raf.getFilePointer();if (currentPosition - 2 * RECORD_SIZE > 0)// Why 2 * 2 * RECORD_SIZE? See the follow-up remarksreadAddress(currentPosition - 2 * 2 * RECORD_SIZE);elsereadAddress(0);}catch (IOException ex) {}});btLast.setOnAction(e -> {try {long lastPosition = raf.length();if (lastPosition > 0)// Why 2 * RECORD_SIZE? See the follow-up remarksreadAddress(lastPosition - 2 * RECORD_SIZE);}catch (IOException ex) {}});btUpdate.setOnAction(e -> {try {writeAddress(raf.getFilePointer() - 2 * RECORD_SIZE); }catch (IOException ex) {}});}/** Write a record at the end of the file */public void writeAddress(long position) {try {raf.seek(position);FixedLengthStringIO.writeFixedLengthString(tfName.getText(), NAME_SIZE, raf);FixedLengthStringIO.writeFixedLengthString(tfStreet.getText(), STREET_SIZE, raf);FixedLengthStringIO.writeFixedLengthString(tfCity.getText(), CITY_SIZE, raf);FixedLengthStringIO.writeFixedLengthString(tfState.getText(), STATE_SIZE, raf);FixedLengthStringIO.writeFixedLengthString(tfZip.getText(), ZIP_SIZE, raf);}catch (IOException ex) {ex.printStackTrace();}}/** Read a record at the specified position */public void readAddress(long position) throws IOException {raf.seek(position);String name = FixedLengthStringIO.readFixedLengthString(NAME_SIZE, raf);String street = FixedLengthStringIO.readFixedLengthString(STREET_SIZE, raf);String city = FixedLengthStringIO.readFixedLengthString(CITY_SIZE, raf);String state = FixedLengthStringIO.readFixedLengthString(STATE_SIZE, raf);String zip = FixedLengthStringIO.readFixedLengthString(ZIP_SIZE, raf);tfName.setText(name);tfStreet.setText(street);tfCity.setText(city);tfState.setText(state);tfZip.setText(zip);}/*** The main method is only needed for the IDE with limited* JavaFX support. Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}class FixedLengthStringIO {/** Read fixed number of characters from a DataInput stream */ public static String readFixedLengthString(int size,DataInput in) throws IOException {// Declare an array of characterschar[] chars = new char[size];// Read fixed number of characters to the arrayfor (int i = 0; i < size; i++)chars[i] = in.readChar();return new String(chars);}/** Write fixed number of characters to a DataOutput stream */ public static void writeFixedLengthString(String s, int size,DataOutput out) throws IOException {char[] chars = new char[size];// Fill in string with characterss.getChars(0, s.length(), chars, 0);// Fill in blank characters in the rest of the arrayfor (int i = Math.min(s.length(), size); i < chars.length; i++) chars[i] = ' ';// Create and write a new string padded with blank charactersout.writeChars(new String(chars));}}17.10import java.io.*;public class Exercise17_10 {public static void main(String[] args) throws Exception {// Check usageif (args.length != 2) {System.out.println("Usage: java Exercise17_10 SourceFile numberOfPieces");System.exit(1);}try (BufferedInputStream input = new BufferedInputStream(new FileInputStream( new File(args[0])));) {int numberOfPieces = Integer.parseInt(args[1]);System.out.println("File size: " + input.available() + " bytes");long fileSize = input.available();int splitFileSize = (int)Math.ceil(1.0 * fileSize / numberOfPieces);for (int i = 1; i <= numberOfPieces; i++) {try (BufferedOutputStream output = new BufferedOutputStream(new FileOutputStream(new File(args[0] + "." + i)));) {int value;int count = 0;// What is wrong if these two conditions are placed in a different order?while (count++ < splitFileSize && (value = input.read()) != -1) { output.write(value);}}}}}}17.11import java.io.*;import javafx.application.Application;import javafx.geometry.Pos;import javafx.scene.Scene;import javafx.scene.control.Button;import bel;import javafx.scene.control.TextField;import yout.GridPane;import yout.HBox;import yout.VBox;import javafx.stage.Stage;public class Exercise17_11 extends Application {private TextField tfInputFile = new TextField();private TextField tfNumberOfFiles = new TextField();private Button btBrowse = new Button("Browse");private Button btStart = new Button("Start");@Overridepublic void start(Stage primaryStage) {GridPane gridPane = new GridPane();gridPane.add(new Label("Enter or choose a file: "), 0, 0);gridPane.add(tfInputFile, 1, 0);gridPane.add(new Label("Specify the number of smaller files: "), 0, 1); gridPane.add( tfNumberOfFiles, 1, 1);HBox hBox = new HBox(5);hBox.getChildren().add(btStart);hBox.setAlignment(Pos.CENTER);VBox vBox = new VBox(5);vBox.getChildren().addAll(new Label("If you split a file named temp.txt into 3 smaller files, \nthe three smaller files are temp.txt.1, temp.txt.2, and temp.txt.3."),gridPane, hBox);// Create a scene and place it in the stageScene scene = new Scene(vBox, 400, 120);primaryStage.setTitle("Exercise17_11"); // Set the stage titleprimaryStage.setScene(scene); // Place the scene in the stageprimaryStage.show(); // Display the stagebtStart.setOnAction(e -> {splitFile(tfInputFile.getText(),Integer.parseInt(tfNumberOfFiles.getText()));});}public void splitFile(String filename, int numberOfPieces) {try (BufferedInputStream input = new BufferedInputStream(new FileInputStream(new File(filename)));) {System.out.println("File size: " + input.available() + " bytes");long fileSize = input.available();int splitFileSize = (int) Math.ceil(1.0 * fileSize / numberOfPieces);for (int i = 1; i <= numberOfPieces; i++) {try (BufferedOutputStream output = new BufferedOutputStream(new FileOutputStream(new File(filename + "." + i)));) {int value;int count = 0;// What is wrong if these two conditions are placed in a different// order?while (count++ < splitFileSize && (value = input.read()) != -1) { output.write(value);}}}} catch (IOException ex) {ex.printStackTrace();}}/*** The main method is only needed for the IDE with limited* JavaFX support. Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}17.12import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;public class Exercise17_12 {public static void main(String[] args) throws Exception {// Check usageif (args.length < 2) {System.out.println("Usage: java Exercise17_12 SourceFile1 ... SoureFilen TargetFile"); System.exit(1);}try (// The last file TargetFile is for outputBufferedOutputStream output = new BufferedOutputStream( new FileOutputStream(new File(args[args.length - 1]))); ) {for (int i = 0; i < args.length - 1; i++) {try (BufferedInputStream input = new BufferedInputStream( new FileInputStream(new File(args[i])));) {int value;while ((value = input.read()) != -1) {output.write(value);}}}}}}17.13import java.io.*;import javafx.application.Application;import javafx.geometry.Pos;import javafx.scene.Scene;import javafx.scene.control.Button;import bel;import javafx.scene.control.TextField;import yout.GridPane;import yout.HBox;import yout.VBox;import javafx.stage.Stage;public class Exercise17_13 extends Application {private TextField tfInputFile = new TextField();private TextField tfNumberOfFiles = new TextField();private Button btBrowse = new Button("Browse");private Button btStart = new Button("Start");@Overridepublic void start(Stage primaryStage) {GridPane gridPane = new GridPane();gridPane.add(new Label("Enter or choose a file: "), 0, 0);gridPane.add(tfInputFile, 1, 0);gridPane.add(new Label("Specify the number of smaller files: "), 0, 1); gridPane.add( tfNumberOfFiles, 1, 1);HBox hBox = new HBox(5);hBox.getChildren().add(btStart);hBox.setAlignment(Pos.CENTER);VBox vBox = new VBox(5);vBox.getChildren().addAll(new Label("If the base file is named temp.txt with three pieces, \ntemp.txt.1, temp.txt.2, and temp.txt.3 are combined into temp.txt."),gridPane, hBox);// Create a scene and place it in the stageScene scene = new Scene(vBox, 400, 120);primaryStage.setTitle("Exercise17_13"); // Set the stage titleprimaryStage.setScene(scene); // Place the scene in the stageprimaryStage.show(); // Display the stagebtStart.setOnAction(e -> {joinFile(tfInputFile.getText(),Integer.parseInt(tfNumberOfFiles.getText()));});}public void joinFile(String filename, int numberOfPieces) {try (// The last file TargetFile is for outputBufferedOutputStream output = new BufferedOutputStream(new FileOutputStream(new File(filename)));) {for (int i = 1; i <= numberOfPieces; i++) {try (BufferedInputStream input = new BufferedInputStream(new FileInputStream(new File(filename + "." + i)));) {int value;while ((value = input.read()) != -1) {output.write(value);}}}}catch (IOException ex) {ex.printStackTrace();}}/*** The main method is only needed for the IDE with limited* JavaFX support. Not needed for running from the command line. */public static void main(String[] args) {launch(args);}}17.14import java.util.Scanner;import java.io.*;public class Exercise17_14 {public static void main(String[] args) throws Exception {Scanner input = new Scanner(System.in);System.out.print("Enter a file to encrypt: ");File inputFile = new File(input.nextLine());System.out.print("Enter the output file: ");File outputFile = new File(input.nextLine());try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(inputFile));BufferedOutputStream output = new BufferedOutputStream( new FileOutputStream(outputFile));) {int value;while ((value = in.read()) != -1) {output.write(value + 5);}}}}17.15import java.util.Scanner;import java.io.*;public class Exercise17_15 {public static void main(String[] args) throws Exception {Scanner input = new Scanner(System.in);System.out.print("Enter an encrypted file: ");File inputFile = new File(input.nextLine());System.out.print("Enter the output file: ");File outputFile = new File(input.nextLine());try (BufferedInputStream in = new BufferedInputStream( new FileInputStream(inputFile));BufferedOutputStream output = new BufferedOutputStream( new FileOutputStream(outputFile));) {int value;while ((value = in.read()) != -1) {output.write(value - 5);}}}}17.16import java.io.*;import java.util.Scanner;public class Exercise17_16 {public static void main(String[] args) throws Exception {Scanner input = new Scanner(System.in);System.out.print("Enter a filename: ");String filename = input.nextLine();int[] counts = new int[128];try (BufferedInputStream fileInput = new BufferedInputStream( new FileInputStream(new File(filename)));) {int r;while ((r = fileInput.read()) != -1 ) {counts[(byte)r]++;}}System.out.printf("%15s%15s\n", "ASCII Code", "Counts");for (int i = 0; i < counts.length; i++)if (counts[i] != 0)System.out.printf("%15d%15d\n", i, counts[i]);}}17.17import java.io.*;public class Exercise17_17 {public static void main(String[] args) throws Exception {BitOutputStream output = new BitOutputStream(newFile("Exercise17_17.dat"));output.writeBit("010000100100001001101");output.close();System.out.println("Done");}public static class BitOutputStream {private FileOutputStream output;private int value;private int count = 0;private int mask = 1; // The bits are all zeros except the last onepublic BitOutputStream(File file) throws IOException {output = new FileOutputStream(file);}public void writeBit(char bit) throws IOException {count++;value = value << 1;if (bit == '1')value = value | mask;if (count == 8) {output.write(value);count = 0;}}public void writeBit(String bitString) throws IOException {for (int i = 0; i < bitString.length(); i++)writeBit(bitString.charAt(i));}/** Write the last byte and close the stream. If the last byte is not full, right-shfit with zeros */public void close() throws IOException {if (count > 0) {value = value << (8 - count);output.write(value);}output.close();}}}17.18import java.io.*;import java.util.Scanner;public class Exercise17_18 {public static void main(String[] args) throws IOException {Scanner input = new Scanner(System.in);System.out.print("Enter a file name: ");String filename = input.nextLine();FileInputStream in = new FileInputStream(filename);int value;while ((value = in.read()) != -1) {System.out.print(getBits(value));}in.close();}public static String getBits(int value) {String result = "";int mask = 1;for (int i = 7; i >= 0; i--) {int temp = value >> i;int bit = temp & mask;result = result + bit;}return result;}}17.19import java.io.*;import java.util.Scanner;public class Exercise17_19 {public static void main(String[] args) throws IOException { Scanner input = new Scanner(System.in);System.out.print("Enter a file name: ");String filename = input.nextLine();FileInputStream in = new FileInputStream(filename);int value;while ((value = in.read()) != -1) {System.out.print(getHex(getBits(value)));}}/** Convert the 8-bit string to a 2-digit hex number */ public static String getHex(String bitString) {// Get the first half hex numberint value = (bitString.charAt(0) - '0') * 8 +(bitString.charAt(1) - '0') * 4 +(bitString.charAt(2) - '0') * 2 +(bitString.charAt(3) - '0') * 1;String result = "" + toHexChar(value);// Get the second half hex numbervalue = (bitString.charAt(4) - '0') * 8 +(bitString.charAt(5) - '0') * 4 +(bitString.charAt(6) - '0') * 2 +(bitString.charAt(7) - '0') * 1;return result + toHexChar(value);}/** Convert an integer to a single hex digit in a character */ public static char toHexChar(int hexValue) {if (hexValue <= 9 && hexValue >= 0)return (char)(hexValue + '0');else// hexValue <= 15 && hexValue >= 10return (char)(hexValue - 10 + 'A');}public static String getBits(int value) {String result = "";int mask = 1;for (int i = 7; i >= 0; i--) {int temp = value >> i;int bit = temp & mask;result = result + bit;}return result;}}17.20import java.io.*;import javafx.application.Application;import javafx.geometry.Pos;import javafx.scene.Scene;import javafx.scene.control.Button;import bel;import javafx.scene.control.ScrollPane;import javafx.scene.control.TextArea;import javafx.scene.control.TextField;import yout.BorderPane;import javafx.stage.Stage;public class Exercise17_20 extends Application {private TextField tfFilename = new TextField();private Button btSave = new Button("Save the change");private TextArea taBits = new TextArea();public void start(Stage primaryStage) {BorderPane pane1 = new BorderPane();pane1.setLeft(new Label("Enter a file: "));pane1.setCenter(tfFilename);BorderPane pane = new BorderPane();pane.setTop(pane1);pane.setCenter(new ScrollPane(taBits));pane.setBottom(btSave);BorderPane.setAlignment(btSave, Pos.CENTER);// Create a scene and place it in the stageScene scene = new Scene(pane, 400, 120);primaryStage.setTitle("Exercise17_20"); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stagetaBits.setWrapText(true);tfFilename.setOnAction(e -> {try {FileInputStream in = newFileInputStream(tfFilename.getText().trim());String s = "";int value;while ((value = in.read()) != -1) {s += getBits(value);}in.close();taBits.setText(s);}catch (IOException ex) {ex.printStackTrace();}});btSave.setOnAction(e -> {try {BitOutputStream output = new BitOutputStream(newFile(tfFilename.getText().trim()));output.writeBit(taBits.getText().trim());output.close();}catch (IOException ex) {ex.printStackTrace();}});}public static String getBits(int value) {String result = "";int mask = 1;for (int i = 7; i >= 0; i--) {int temp = value >> i;int bit = temp & mask;result = result + bit;}return result;}public static class BitOutputStream {private FileOutputStream output;private int value;private int count = 0;private int mask = 1; // The bits are all zeros except the last onepublic BitOutputStream(File file) throws IOException {output = new FileOutputStream(file);}public void writeBit(char bit) throws IOException {count++;value = value << 1;if (bit == '1')value = value | mask;if (count == 8) {output.write(value);count = 0;}}public void writeBit(String bitString) throws IOException {for (int i = 0; i < bitString.length(); i++)writeBit(bitString.charAt(i));}/** Write the last byte and close the stream. If the last byte is not full, right-shfit with zeros */public void close() throws IOException {if (count > 0) {value = value << (8 - count);output.write(value);}output.close();}}/*** The main method is only needed for the IDE with limited* JavaFX support. Not needed for running from the command line.*/public static void main(String[] args) {launch(args);}}17.21import java.io.*;import javafx.application.Application;import javafx.geometry.Pos;import javafx.scene.Scene;import javafx.scene.control.Button;import bel;import javafx.scene.control.ScrollPane;import javafx.scene.control.TextArea;import javafx.scene.control.TextField;import yout.BorderPane;import javafx.stage.Stage;public class Exercise17_21 extends Application {private TextField tfFilename = new TextField();private Button btSave = new Button("Save the change");private TextArea taBits = new TextArea();public void start(Stage primaryStage) {BorderPane pane1 = new BorderPane();pane1.setLeft(new Label("Enter a file: "));pane1.setCenter(tfFilename);BorderPane pane = new BorderPane();pane.setTop(pane1);pane.setCenter(new ScrollPane(taBits));pane.setBottom(btSave);BorderPane.setAlignment(btSave, Pos.CENTER);// Create a scene and place it in the stageScene scene = new Scene(pane, 400, 120);primaryStage.setTitle("Exercise17_21"); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stagetaBits.setWrapText(true);tfFilename.setOnAction(e -> {try {FileInputStream in = newFileInputStream(tfFilename.getText().trim());String s = "";int value;while ((value = in.read()) != -1) {s += getHex(getBits(value));}in.close();taBits.setText(s);}catch (IOException ex) {ex.printStackTrace();}});btSave.setOnAction(e -> {try {BitOutputStream output = new BitOutputStream(newFile(tfFilename.getText().trim()));output.writeBit(toBits(taBits.getText().trim()));output.close();}。

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