Java语言程序设计基础篇编程练习题-第二章

痛定思痛。 2022-12-05 13:50 193阅读 0赞

### 2.1（摄氏温度转华氏温度） ###

import java.util.Scanner;
    public class Test2_01 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter a degree in Celsius:");
    //		double celsius = input.nextDouble();
    		int celsius = input.nextInt();
    		input.close();
    		double fahrenheit = (9.0 / 5) * celsius + 32;
    		System.out.println(celsius + " Celsius is " + fahrenheit + " Fahrenheit");
    	}
    }

### 2.2（计算圆柱体的体积） ###

import java.util.Scanner;
    public class Test2_02 {
        
    	public static void main(String[] args) {
        
    		final double p = 3.1415926;
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the radius and length of a cylinder: ");
    		double radius = input.nextDouble();
    		double length = input.nextDouble();
    		input.close();
    		double area = radius * radius * p;
    		double volume = area * length;
    		System.out.println("The area is " + area);
    		System.out.println("The volume is " + volume);
    	}
    }

### 2.3（将英尺转换为米） ###

import java.util.Scanner;
    public class Test2_03 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter a value for feet: ");
    		double feet = input.nextDouble();
    		input.close();
    		double meters = 0.305 * feet;
    		System.out.println(feet + " feet is " + meters + " meters");
    	}
    }

### 2.4（将磅转换为千克） ###

import java.util.Scanner;
    public class Test2_04 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter a number in pounds: ");
    		double pounds = input.nextDouble();
    		input.close();
    		double kilograms = pounds * 0.454;
    		System.out.println(pounds + " pounds is " + kilograms + " kilograms");
    	}
    }

### 2.5（财务应用程序，计算小费） ###

import java.util.Scanner;
     
    public class Test2_05 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the subtotal and a gratuity rate:");
    		double subtotal = input.nextDouble();
    		double rate = input.nextDouble();
    		input.close();
    		double gratuity = rate / 100 * subtotal; 
    		System.out.println("The gratuity is $" + gratuity + " and total is $" + (gratuity + subtotal));
    	}
    }

### 2.6（求一个整数各位数的和） ###

import java.util.Scanner;
     
    public class Test2_06 {
        
    	public static void main(String[] args) {
        
    		Scanner scan = new Scanner(System.in);
    		System.out.print("Enter a number between 0 and 1000: ");
    		int number = scan.nextInt();
    		scan.close();
    		int num1 = number % 10;
    		int num2 = number / 10 % 10;
    		int num3 = number / 100;
    		int sum = num1 + num2 + num3;
    		System.out.println("The sum of the digits is " + sum);
    	}
    }

### 2.7（求出年数） ###

import java.util.Scanner;
     
    public class Test2_07 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the number of minutes: ");
    		int minutes = input.nextInt();
    		input.close();
    		
    		int days = minutes / 60 / 24;
    		int years = days / 365;
    		int day = days % 365;
    		
    		System.out.println(minutes + " minuise is approximately " + years + " years and " + day + " days");
    	}
    }

### 2.8（当前时间） ###

import java.util.Scanner;
     
    public class Test2_08 {
        
    	public static void main(String[] args) {
        
    		//获取系统时钟数
    		long totalMilliseconds = System.currentTimeMillis();
    		//整除1000得到总秒数
    		long totalSeconds = totalMilliseconds / 1000;
    		//总秒数对 60 取余得当现在时间的秒数
    		long currentSeconds = totalSeconds % 60;
    		//总秒数对 60 取整得当现在时间的总分钟数
    		long totalMinutes = totalSeconds / 60;
    		//总分钟数对 60 取余得当现在时间的分钟数
    		long currentMinute = totalMinutes % 60;
    		//总分钟数对 60 取整得当现在时间的总小时数
    		long totalHours = totalMinutes / 60;
    		//总小时数对 24 取余得当现在时间的小时数
    		long currentHour = totalHours % 24;
    		
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the time zone offset to GMT: ");
    		int time = input.nextInt();
    		input.close();
    		int hour = (int)currentHour + time;
    		System.out.println("The current time is " + hour + ":" + currentMinute + ":" + currentSeconds);
    	}
    }

### 2.9（物理，加速度） ###

import java.util.Scanner;
     
    public class Test2_09 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter v0, v1, and t: ");
    		double v0 = input.nextDouble();
    		double v1 = input.nextDouble();
    		double t = input.nextDouble();
    		input.close();
    		
    		double acc = (v1 - v0) / t;
    		
    		System.out.println("The average acceleration is " + acc);
    	}
    }

### 2.10（科学，计算能量） ###

import java.util.Scanner;
     
    public class Test2_10 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the amount of water in kilograms: ");
    		double m = input.nextDouble();
    		System.out.print("Enter the initial temperature: ");
    		double inT = input.nextDouble();
    		System.out.print("Enter the final temperature: ");
    		double finalT = input.nextDouble();
    		input.close();
    		
    		double Q = m * (finalT - inT) * 4184;
    		
    		System.out.println("The energy needed is " + Q);
    	}
    }

### 2.11（人口统计） ###

import java.util.Scanner;
     
    public class Test2_11 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the number of years: ");
    		int years = input.nextInt();
    		input.close();
    		int num = 312032486;
    		int time = 3600 * 24 * 365;
    		int birth = time / 7;
    		int die = time / 13;
    		int in = time / 45;
    		int change = birth + in - die;
    		for(int i = 0; i < years; i++) {
        
    			num += change; 
    		}
    		System.out.println("The population in " + years + " years is " + num);
    	}
    }

### 2.12（物理：求出跑道长度） ###

import java.util.Scanner;
     
    public class Test2_12 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter speed and acceleration: ");
    		double speed = input.nextDouble();
    		double acc = input.nextDouble();
    		input.close();
    		double length = (speed * speed) / (2 * acc);
    		System.out.println("The minmum runway length for this airplane is " + length);
    	}
    }

### 2.13（财务应用程序：复利值） ###

import java.util.Scanner;
    
    public class Test2_13 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the monthly saving amount: ");
    		double amount = input.nextDouble();
    		input.close();
    		double value = 0;
    		for(int i = 0; i < 6; i++) {
        
    			value = (amount + value) * (1 + 0.00417);
    		}
    		System.out.println("After the sixth month, the account value is $" + value);
    	}
    }

### 2.14（医疗应用程序：计算BMI） ###

import java.util.Scanner;
    
    public class Test2_14 {
        
    	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();
    		input.close();
    		weight = weight * 0.4539237;
    		height = height * 0.0254;
    		double bmi = weight / (height * height);
    		System.out.println("BMI is " + bmi);
    	}
    }

### 2.15（几何：两点之间的距离） ###

import java.util.Scanner;
    public class Test2_15 {
        
    	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 ang y2: ");
    		double x2 = input.nextDouble();
    		double y2 = input.nextDouble();
    		input.close();
    		double d1 = Math.pow((x2 - x1),2);
    		double d2 = Math.pow((y2 - y1),2);
    		double distance = Math.pow(d1 + d2, 0.5);
    		System.out.println("The distance between the points is " + distance);
    	}
    }

### 2.16（几何，六边形面积） ###

import java.util.Scanner;
    
    public class Test2_16 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the side: ");
    		double side = input.nextDouble();
    		input.close();
    		double area = 3 * Math.pow(3, 0.5) / 2 * side * side;
    		System.out.println("The area of the hexagon is " + area);
    	}
    }

### 2.17（科学，风寒温度） ###

import java.util.Scanner;
    
    public class Test2_17 {
        
    	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: ");
    		int wind = input.nextInt();
    		input.close();
    		double d = Math.pow(wind, 0.16);
    		double t = 35.74 + 0.6215 * temperature - 35.75 * d + 0.4275 * temperature * d;
    		System.out.println("The wind chill index is " + t);
    	}
    }

### 2.18（打印表格） ###

import java.util.Scanner;
    
    public class Test2_18 {
        
    	public static void main(String[] args) {
        
    		System.out.println("a\tb\tpow(a,b)");
    		for(int a = 1; a <= 5; a++) {
        
    			int b = a + 1;
    			int pow = (int)(Math.pow(a, b));
    			System.out.println(a + "\t" + b + "\t" + pow);
    		}
    	}
    }

### 2.19（几何：三角形的面积） ###

import java.util.Scanner;
    
    public class Test2_19 {
        
    	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();
    		input.close();
    		
    		double s1 = Math.pow(Math.pow((x2 - x1),2) + Math.pow((y2 - y1),2), 0.5);
    		double s2 = Math.pow(Math.pow((x2 - x3),2) + Math.pow((y2 - y3),2), 0.5);
    		double s3 = Math.pow(Math.pow((x3 - x1),2) + Math.pow((y3 - y1),2), 0.5);
    		double s = (s1 + s2 + s3) / 2;
    		
    		double area = Math.pow(s * (s - s1) * (s - s2) * (s - s3), 0.5);
    		System.out.println("The area of the triangle is " + area);
    	}
    }

### 2.20（财务应用程序：计算利息） ###

import java.unit.Scanner;
    
    public class Test2_20 {
        
    	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 rate = input.nextDouble();
    		input.close();
    		double amount = balance * (rate / 1200);
    		System.out.println("The interest is " + amount);
    	}
    }

### 2.21（财务应用：计算未来投资值） ###

import java.util.Scanner;
    
    public class Test2_21 {
        
    	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:");
    		int years = input.nextInt();
    		input.close();
    		double value = amount * Math.pow((1 + rate/1200), (years * 12));
    		System.out.println("Accumulated value is $" + value);
    	}
    }

### 2.22（财务应用：货币单位） ###

import java.util.Scanner;
    
    public class Test2_22 {
        
    	public static void main(String[] args) {
        
    		Scanner input = new Scanner(System.in);
    		System.out.print("Enter the number: ");
    		int num = input.nextInt();
    		input.close();
    		int num1 = num / 100;
    		int num2 = num % 100;
    		System.out.println(num + " is " + num1 + " dollars and " + num2 + " cents.");
    	}
    }

### 2.23（驾驶费用） ###

import java.util.Scanner;
    
    public class Test2_23 {
        
    	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 miles = input.nextDouble();
    		System.out.print("Enter price per gallon: ");
    		double price = input.nextDouble();
    		input.close();
    		double cost = distance / miles * price;
    		System.out.println("The cost of driving is $" + cost);
    	}
    }

以上代码均为个人编写，不当之处，悉请指正。