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

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 + \ 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+\ for(int j=2;j

5.23演示抵消错误，n取50000 package pro0910; public class Wrong {

public static void main(String[] args) { double sum1 = 0; double sum2 = 0;

for (int i = 1; i < 50001; i++) { sum1 = sum1 + 1.0 / i; }

for (int i = 50000; i > 0; i--) { sum2 = sum2 + 1.0 / i; }

System.out.println(\从左往右加sum1=\ System.out.print(\从右往左加sum2=\ } }

5.26计算e，使用下面的数列可以近似计算e package 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;j

System.out.println(\当i=\时，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(\ for (int i=1;i

money=money+money*rate/1200; System.out.println(i+\ } } }

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;n<100;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：\ game(choose,computer);

if (i==2||j==2){System.out.print(\游戏结束\ 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！\ } } }