第五次上机作业

1.打印出所有的"水仙花数"，所谓"水仙花数"是指一个三位数，其各位数字立方和等于该数本身。例如：153是一个"水仙花数"，因为153=1的三次方＋5的三次方＋3的三次方。

package test1;

public class test2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for(int i=100;i<=999;i++){
            int a=i/100;
            int b=i%100/10;
            int c=i%10; 
            if(a*a*a+b*b*b+c*c*c==i){
            System.out.println("水仙花数为:"+i);
            }
            
        }
    }

}

2.在控制台输出以下图形

package test1;

public class test2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for(int i = 1;i <= 6;i++) {
            for(int j = 0;j < i;j++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }

}

package test1;

public class test2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for(int i = 0;i < 6;i++) {
            for(int j = i;j < 6;j++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }

}

package test1;

public class test2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for(int i = 1;i <= 6;i++) {
            for(int j = 1;j <= 6-i;j++) {
                System.out.print(" ");
            }
            for(int j = 1;j <= i;j++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }

}

package test1;

public class test2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for(int i = 1;i <= 6;i++) {
            for(int j = 1;j <= i-1;j++) {
                System.out.print(" ");
            }
            for(int j = 1;j <= 7-i;j++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }

}

3.输入年月日，判断这是这一年中的第几天

package test1;
import java.util.Scanner;
public class test2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("请分别输入一个四位数的值:");
        Scanner input=new Scanner(System.in);
        System.out.println("year：");
        System.out.println("month：");
        System.out.println("days：");
        
        int year=input.nextInt();
        int month=input.nextInt();
        int days=input.nextInt();
        
        int X = 0;
        for(int i = 1;i < month;i++) {
            switch(i) {
            case 4:
            case 6:
            case 9:
            case 11:
                X += 30;
                break;
            case 2:
                if(year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
                    X += 29;
                }else
                    X += 28;
                break;
            default: X += 31;
            break;
                }
            }
        X += days;
        System.out.println("这天是今年的第"+ X +"天");
        }
    }

4．由控制台输入一个4位整数，求将该数反转以后的数，如原数为1234，反转后的数位4321

package test1;
import java.util.Scanner;
public class test2 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("请分别输入一个四位数的值:");
        Scanner input=new Scanner(System.in);
        int N=input.nextInt();
        int a,b,c,d,e;
        a=N/1000;
        b=N/100%10;
        c=N/10%10;
        d=N%10;
        e=d*1000+c*100+b*10+a;
        System.out.println("反转后为"+e);
    }

}