java第五章节作业

public class homework01{
	public static void main(String[] args){
		double money = 100000;//还有多少钱
		int count = 0;//累积过路的次数
		while(true){//默认条件为真
			if(money >50000)
			{
			money *= 0.95;//通过路口，还有这么多钱
			count++;//计数
			}
			else if(money >=1000 )
			{
			money -= 1000;//通过路口，还有这么多钱
			count++;//计数
			}
			else//钱不够1000
			{
				break;
			}
		}
		System.out.println("100000可以经过"+ count + "次路口");
	}
}

import java.util.Scanner;
public class homework02{
	public static void main(String[] args){
		Scanner myScanner = new Scanner(System.in);//创建Scanner对象
		System.out.println("请输入一个数字：");
		double num =myScanner.nextDouble();
		if(num > 0){
			System.out.println("大于0");
		}else if(num == 0){
			System.out.println("等于0");
		}else{
			System.out.println("小于0");
		}

	}
}

import java.util.Scanner;
public class homework03{
	public static void main(String[] args){
		Scanner myScanner = new Scanner(System.in);//创建Scanner对象
		System.out.println("请输入一个年份：");
		int year =myScanner.nextInt();
		if(year % 4 ==0){
			System.out.println(year + "是闰年");
		}else{
			System.out.println(year + "不是闰年");
		}

	}
}

import java.util.Scanner;
public class homework04{
	public static void main(String[] args){
		Scanner myScanner = new Scanner(System.in);//创建Scanner对象
		System.out.println("请输入一个数字：");
		int num =myScanner.nextInt();
		int a = num / 100;//百位
		int b = num / 10 % 10;//十位
		int c = num % 10;//个位
		if(num == a * a * a + b * b * b + c * c * c){
			System.out.println(num + "是水仙花数");
		}else{
			System.out.println(num + "不是水仙花数");
		}

	}
}

此题不输出

public class homework06{
	public static void main(String[] args){
		int count = 0;//定义一个计数的count
		for(int i = 1; i <= 100; i++){
			if( i % 5 != 0){//输出能被5整除的数
				count++;//有一个数就计一次数
				System.out.print( i + "\t");//每个数字之间用空格分开
				if(count % 5 == 0){//每5个数字换一次行
				System.out.print('\n');//换行
				}				
			}
		}
	}
}

public class homework07{
	public static void main(String[] args){
		
   		for(char c1 = 'a'; c1 <= 'z'; c1++){
        System.out.print(c1 + " ");
    }
    for(char c2 = 'Z'; c2 >= 'A'; c2--){
        System.out.print(c2 + " ");
    }

	}
}

public class homework08{
	public static void main(String[] args){
		double sum = 0;
		for(int n = 1;n <= 100 ;n++){
			if( n % 2 == 0){//分母为偶数
				sum -= 1.0 / n;//隐藏的陷阱，要把分式分子1写成1.0才能得到精确的小数，否则会丢失数据
			}else{//分母为奇数
				sum += 1.0 / n;
			}
		}
		System.out.println("sum=" + sum);
	}
}

public class homework09{
	public static void main(String[] args){
		int sum = 0;
		for(int i = 1; i <= 100; i++){
		for(int j = 1; j <= i ; j++){//内层对1-i进行循环
			sum +=j;
		}
		}
		System.out.println("sum=" + sum);

	}
}