Java语言程序设计基础篇原书第十一版梁勇第5、6章课后题答案.doc

5.10显示从100到1000之间所有能被5和6整除的数，每行显示10个package pro0910;public class Num public static void main(String args) int a = 0; for (int i = 100; i 1000; i+) if (i % 5 = 0 | i % 6 = 0) System.out.print(i + t); a += 1; if (a = 10) System.out.println(); a = 0; 5.17编写程序，提示用户输入一个在1到15之间的整数，然后显示一个金字塔形状package pro0910;import java.util.Scanner;public class Text public static void main(String args) Scanner in=new Scanner(System.in); System.out.print(输入一个在1到15之间的整数：); int line =in.nextInt(); for(int i=1;i=line;i+) for(int j=0;j0;j-=1)System.out.print(j+t); for(int j=2;ji+1;j+=1)System.out.print(j+t); System.out.println(); 5.23演示抵消错误，n取50000package pro0910;public class Wrong public static void main(String args) double sum1 = 0; double sum2 = 0; for (int i = 1; i 0; i-) sum2 = sum2 + 1.0 / i; System.out.println(从左往右加sum1=+sum1); System.out.print(从右往左加sum2=+sum2); 5.26计算e，使用下面的数列可以近似计算epackage pro0910;public class E public static void main(String args) double sum = 1; double e = 1; for (int i = 10000; i 110000; i+=10000) for (int j=1;ji;j+) sum*=j; e+=1.0/sum; System.out.println(当i=+i+时，e=+e); 5.31计算CD价值package pro0910;import java.util.Scanner;public class CD public static void main(String args) Scanner in=new Scanner(System.in); System.out.print(请输入金额：); double money=in.nextDouble(); System.out.print(请输入年利率：); double rate=in.nextDouble(); System.out.print(请输入月份数：); int month=in.nextInt(); System.out.println(MonthttCD Value); for (int i=1;imonth+1;i+) money=money+money*rate/1200; System.out.println(i+tt+money); 5.34剪刀石头布public class Game private static int i=0; private static int j=0; public static void main(String args) for (int n=1;n100;n+) System.out.println(输入一个数：0是剪刀，1是石头，2是布); Scanner in = new Scanner(System.in); System.out.print(请输入你的选择：); int choose=in.nextInt(); int computer=(int)(Math.random()*3+0); System.out.println(电脑的选择：+computer); game(choose,computer); if (i=2|j=2)System.out.print(游戏结束);break; System.out.println(); public static void game(int n1,int n2) if (n1=n2) System.out.println(平局); else if (n1=0) if (n2=1)j+; System.out.println(你输了！); else i+; System.out.println(你赢了！); else if(n1=1) if (n2=0)i+; System.out.println(你赢了！); else j+; System.out.println(你输了！); else if (n2=0)j+; System.out.println(你输了！); else i+; System.out.println(你赢了！); 5.45计算平均值和标准方差public class TongJi public static void main(String args) int i=10; double sum=0; double mean; double num=0; double standard; double list=new doublei; System.out.print(请输入10个数：); Scanner in=new Scanner(System.in); for (i=0;i10;i+) listi = in.nextDouble(); sum += listi; num += Math.pow(listi,2); mean=sum/10; double a=num-Math.pow(sum,2)/i; standard=Math.pow(a/(i-1),0.5); System.out.println(平均值是：+mean); System.out.print(方差是：+standard); 5.47商业：检测ISBN-13public class Text public static void main(String args) Scanner in=new Scanner(System.in); System.out.print(请输入ISBN-13：); String str=in.next(); int length=str.length(); if (length!=12) System.out.println(请输入正确的ISBN-13码); char d1=str.charAt(0);char d2=str.charAt(1);char d3=str.charAt(2); char d4=str.charAt(3);char d5=str.charAt(4);char d6=str.charAt(5); char d7=str.charAt(6);char d8=str.charAt(7);char d9=str.charAt(8); char d10=str.charAt(9);char d11=str.charAt(10);char d12=str.charAt(11); int d=10-(d1-48+(d2-48)*3+d3+(d4-48)*3+d5+(d6-48)*3+d7+(d8-48)*3+d9+(d10-48)*3+d11+(d12-48)*3)%10; if (d = 10) int d13=0;System.out.print(ISBN-13是:+d1+d2+d3+d4+d5+d6+d7+d8+d9+d10+d11+d12+d13); else System.out.print(ISBN-13是：+d1+d2+d3+d4+d5+d6+d7+d8+d9+d10+d11+d12+d); 6.7计算未来投资回报值public class Money public static void main(String args) Scanner in=new Scanner(System.in); System.out.print(请输入本金：); double investmentAmount=in.nextDouble(); System.out.print(请输入利率：); double monthlyInterestRate=in.nextDouble(); System.out.print(请输入年份：); int years=in.nextInt(); futureInvestementValue(investmentAmount,monthlyInterestRate,years); public static double futureInvestementValue(double investmentAmount,double monthlyInterestRate,int years) System.out.println(YearsttFuture Value); for (int i=1;iyears+1;i+) double value=investmentAmount*Math.pow(1+monthlyInterestRate/1200,12); investmentAmount=value; System.out.println(i+tt+value); return 0; 6.9英尺和米之间的转换public class Meters public static void main(String args) System.out.println(英尺tt米tttt米tt英尺); for (int i=1,j=20;i11;i+,j+=5) System.out.println(i+tt+footToMeters(i)+ttt+j+tt+meterToFoot(j); public static double footToMeters(double foot) double meter=0.305*foot; return meter; public static double meterToFoot(double meter) double foot=3.279*meter; return foot; 6.14估算public class Pi public static void main(String args) mathToPi(1); public static void mathToPi(int j) System.out.println(ittm(i); for (;j1000;j+=100) double sum=0; double m; for (int i=1;i=j;i+) sum=sum+Math.pow(-1,i+1)/(2*i-1); m=4*sum; System.out.println(j+tt+m); 6.18检测密码public class Pass public static void main(String args) Scanner in=new Scanner(System.in); System.out.print(请输入密码：); String str=in.next(); password(str); public static void password(String str) boolean a=str.matches(A-Za-z0-98,); int num=0; for (int i=0;i= 0 &ch2) System.out.println(密码正确); else System.out.print(密码错误); 6.30游戏：双骰子游戏public class Ace public static void main(String args) int sum=random(); rusult(sum); public static int random() int a=(int)(Math.random()*6+1); int b=(int)(Math.random()*6+1); int sum=a+b; System.out.println(a+b+=+sum); return sum; public static void rusult(int sum) if (sum=2|sum=3|sum=12) System.out.printl