Java语言程序设计（基础篇）（第10版）[美]梁勇
第二章课后题P59
//P59 Chapter_2_practise
/*
//T2_1
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
System.out.println("Enter a degree in Celsius: ");
double celsius=input.nextDouble();
double fahrenheit=(9.0/5)*celsius+32;
System.out.println(celsius+" Celsius is "+fahrenheit+" Fahrenheit");
}
}
*/
/*
//T2_2
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
final double PI=3.14159;
System.out.println("Enter the radius and length of a cylender: ");
double radius=input.nextDouble();
double length=input.nextDouble();
double area=PI*radius*radius;
double volume=area*length;
System.out.println("The area is "+area);
System.out.println("The volume is "+volume);
}
}
*/
/*
//T2_3
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
System.out.println("Enter a value for feet: ");
double feet=input.nextDouble();
double meter=feet*0.305;
System.out.println(feet+" feet is "+meter+" meters");
}
}
*/
/*
//T2_4
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
System.out.println("Enter a number in pounds: ");
double pound=input.nextDouble();
double kilogram=pound*0.454;
System.out.println(pound+" pounds is "+kilogram+" kilograms");
}
}
*/
/*
//T2_5
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
System.out.println("Enter the subtotal and a gratuity rate: ");
double subtotal=input.nextDouble();
double gratuityRate=input.nextDouble();
double gratuity=subtotal*gratuityRate/100.0;//100也可以
double total=gratuity+subtotal;
System.out.println("The gratuity is $"+gratuity+" and total is $"+total);
}
}
*/
/*
//T2_6
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
System.out.println("Enter a number between 0 and 1000: ");
int number=input.nextInt();
int unitsDigit=number%10;//个位数
int tensDigit=(number/10)%10;//十位数
int hundredsDigit=number/100;//百位数
int sum=unitsDigit+tensDigit+hundredsDigit;
System.out.println("The sum of the digits is "+sum);
}
}
*/
/*
//T2_7
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
System.out.println("Enter the number of minutes: ");
long minutes=input.nextLong();
long days=minutes/60/24;
long years=days/365;
long day=days%365;
System.out.println(minutes+" minutes is approximately "+years+" years and "+day+" days");
}
}
*/
/*
//T2_8
import java.util.Scanner;
public class Chapter_2_practise {
public static void main(String[] args) {
// TODO 自动生成的方法存根
Scanner input =new Scanner(System.in);
System.out.print("Enter the time zone offset to GMT: ");
long offset=input.nextLong();
long totalMilliseconds=System.currentTimeMillis()+offset*60*60*1000;//加时差并转化成毫秒
long totalSeconds=totalMilliseconds/1000;//总共的秒数
long currentSecond=totalSeconds%60;//现在的秒
long totalMinutes=totalSeconds/60;//总共的分钟数
long currentMinute=totalMinutes%60;//现在的分钟
long totalHours=totalMinutes/60;//总共的小时数
long currentHour=totalHours%24;//现在的小时
System.out.println("Current time is "+currentHour+":"+currentMinute+":"+currentSecond+" GMT");
}
}
*/
/*
//T2_9
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter v0, v1, and t: ");
double v0,v1,t;
v0=input.nextDouble();
v1=input.nextDouble();
t=input.nextDouble();
double a=(v1-v0)/t;
System.out.print("The average acceleration is "+a);
}
}
*/
/*
//T2_10
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter the amount of water in kilograms: ");
double waterAmount=input.nextDouble();
System.out.print("Enter the initial temperature: ");
double initialTemperature=input.nextDouble();
System.out.print("Enter the final temperature: ");
double finalTemperature=input.nextDouble();
double energy=waterAmount*(finalTemperature-initialTemperature)*4184;
System.out.print("The energy needed is "+energy);
}
}
*/
/*
//T1_11
public class Chapter_2_practise{
public static void main(String[] args) {
int population=312032486;
double daita=365*24*3600*(1.0/7-1.0/13+1.0/45);
int p1=population+(int)daita;
int p2=population+(int)(2*daita);
int p3=population+(int)(3*daita);
int p4=population+(int)(4*daita);
int p5=population+(int)(5*daita);
System.out.println("The population in 1 year is "+p1);
System.out.println("The population in 2 years is "+p2);
System.out.println("The population in 3 years is "+p3);
System.out.println("The population in 4 years is "+p4);
System.out.println("The population in 5 years is "+p5);
}
}
*/
/*
//T2_11 改写T1_11
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter the number of years: ");
int year=input.nextInt();
int population=312032486;
double daita=365*24*3600*(1.0/7-1.0/13+1.0/45);
int newPopulation=population+(int)(year*daita);
System.out.print("The population in"+year+" years is "+newPopulation);
}
}
*/
/*
//T2_12
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter speed and acceleration: ");
double speed=input.nextDouble();
double acceleration=input.nextDouble();
double length=speed*speed/2/acceleration;
System.out.print("The minimum runway length for this airplane is "+length);
}
}
*/
/*
//T2_13
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter the monthly saving amount: ");
double savingAmount=input.nextDouble();
double after1month=savingAmount*(1+0.05/12);
double after2months=(100+after1month)*(1+0.05/12);
double after3months=(100+after2months)*(1+0.05/12);
double after4months=(100+after3months)*(1+0.05/12);
double after5months=(100+after4months)*(1+0.05/12);
double after6months=(100+after5months)*(1+0.05/12);
System.out.print("After the sixth month, the account value is $"+after6months);
}
}
*/
/*
//T5_30循环简化T2_13
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter the monthly saving amount: ");
double sum=input.nextDouble();
double newAccountValue=0;
for(int i=0;i<6;i++)
{
newAccountValue=sum*(1+0.05/12);
sum=100+newAccountValue;
}
System.out.print("After the sixth month, the account value is $"+newAccountValue);
}
}
*/
/*
//T2_14
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter weight in pounds: ");
double weight=input.nextDouble();
System.out.print("Enter height in inches:");
double height=input.nextDouble();
weight*=0.45359237;
height*=0.0254;
double BMI=weight/(height*height);
System.out.print("BMI is "+BMI);
}
}
*/
/*
//T2_15
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter x1 and y1: ");
double x1=input.nextDouble();
double y1=input.nextDouble();
System.out.print("Enter x2 and y2: ");
double x2=input.nextDouble();
double y2=input.nextDouble();
double distance=Math.pow((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2),0.5);
System.out.print("The distance between the two points is "+distance);
}
}
*/
/*
//T2_16
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter the side: ");
double side=input.nextDouble();
double area=3*Math.pow(3,0.5)*side*side/2;
System.out.print("The area of the hexagon is "+area);
}
}
*/
/*
//T2_17
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter the temperature in Fahrenheit between -58F and 41F: ");
double temperature=input.nextDouble();
System.out.print("Enter the wind speed (>=2) in miles per hour: ");
double speed=input.nextDouble();
double index=35.74+0.6215*temperature-35.75*Math.pow(speed,0.16)+0.4275*temperature*Math.pow(speed,0.16);
System.out.print("The wind chill index is "+index);
}
}
*/
/*
//T2_18
public class Chapter_2_practise{
public static void main(String[] args) {
System.out.println("a b pow(a,b)");
System.out.println(1+" "+2+" "+(int)Math.pow(1,2));
System.out.println(2+" "+3+" "+(int)Math.pow(2,3));
System.out.println(3+" "+4+" "+(int)Math.pow(3,4));
System.out.println(4+" "+5+" "+(int)Math.pow(4,5));
System.out.println(5+" "+6+" "+(int)Math.pow(5,6));
}
}
*/
/*
//T2_19
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter three points for a triangle: ");
double x1=input.nextDouble();
double y1=input.nextDouble();
double x2=input.nextDouble();
double y2=input.nextDouble();
double x3=input.nextDouble();
double y3=input.nextDouble();
double side1=Math.pow((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2),0.5);
double side2=Math.pow((x1-x3)*(x1-x3)+(y1-y3)*(y1-y3),0.5);
double side3=Math.pow((x3-x2)*(x3-x2)+(y3-y2)*(y3-y2),0.5);
double side=(side1+side2+side3)/2;
double area=Math.pow(side*(side-side1)*(side-side2)*(side-side3),0.5);
System.out.print("The area of the triangle is "+area);
}
}
*/
/*
//T2_20
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter balance and interest rate(e.g.,3 for 3%): ");
double balance=input.nextDouble();
double interestRate=input.nextDouble();
double interest=balance*interestRate/1200;
System.out.print("The interes is "+interest);
}
}
*/
/*
//T2_21
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter investment amount: ");
double amount=input.nextDouble();
System.out.print("Enter annual interest rate in percentage: ");
double rate=input.nextDouble();
System.out.print("Enter number of years: ");
double years=input.nextDouble();
double accumulatedValue=amount*Math.pow((1+rate/12/100),years*12);
System.out.print("Accumulated value is $"+accumulatedValue);
}
}
*/
/*
//程序清单2-10
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter an amount in double, for example, 11.56: ");
double amount=input.nextDouble();
int remainingAmount=(int)(amount*100);
int numberOfOneDollars=remainingAmount/100;
remainingAmount%=100;
int numberOfQuarters=remainingAmount/25;
remainingAmount%=25;
int numberOfDimes=remainingAmount/10;
remainingAmount%=10;
int numberOfNickels=remainingAmount/5;
remainingAmount%=5;
int numberOfPennies=remainingAmount;
System.out.println("Your amount "+amount+" consists of");
System.out.println(" "+numberOfOneDollars+" dollars");
System.out.println(" "+numberOfQuarters+" quarters");
System.out.println(" "+numberOfDimes+" dimes");
System.out.println(" "+numberOfNickels+" nickels");
System.out.println(" "+numberOfPennies+" pennies");
}
}
*/
/*
//T2_22
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter an amount in int, for example, 1156: ");
int amount=input.nextInt();
int remainingAmount=amount;
int numberOfOneDollars=remainingAmount/100;
remainingAmount%=100;
int numberOfQuarters=remainingAmount/25;
remainingAmount%=25;
int numberOfDimes=remainingAmount/10;
remainingAmount%=10;
int numberOfNickels=remainingAmount/5;
remainingAmount%=5;
int numberOfPennies=remainingAmount;
System.out.println("Your amount "+amount+" consists of");
System.out.println(" "+numberOfOneDollars+" dollars");
System.out.println(" "+numberOfQuarters+" quarters");
System.out.println(" "+numberOfDimes+" dimes");
System.out.println(" "+numberOfNickels+" nickels");
System.out.println(" "+numberOfPennies+" pennies");
}
}
*/
//2_23
import java.util.Scanner;
public class Chapter_2_practise{
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.print("Enter the driving distance: ");
double distance=input.nextDouble();
System.out.print("Enter miles per gallon: ");
double rate=input.nextDouble();
System.out.print("Enter price per gallon: ");
double price=input.nextDouble();
double cost=distance/rate*price;
System.out.print("The cost of driving is $"+cost);
}
}