第五周上机

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。（知识点：循环语句、条件语句）

package book1;

public class five01 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for(int i=100;i<1000;i++) {
            int ge=i%10;
            int shi=i/10%10;
            int bai=i/100;
            if(ge*ge*ge+shi*shi*shi+bai*bai*bai==i) {
                System.out.println(i);
            }
        }

    }

}

2.在控制台输出以下图形（知识点：循环语句、条件语句）

package book1;

public class asd {

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

    }

}

package book1;

public class asd {

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

    }

}

package book1;

public class asd {

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

    }

}

package book1;

public class asd {

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

    }

}

3. 输入年月日，判断这是这一年中的第几天（知识点：循环语句、条件语句）

package qwe;

import java.util.*;

public class test4 {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int day = 0;
        int month = 0;
        int year = 0;
        int sum = 0;
        int a;
        Scanner input = new Scanner(System.in);
        System.out.println("请输入年:");
        year = input.nextInt();
        System.out.println("请输入月:");
        month = input.nextInt();
        System.out.println("请输入日:");
        day = input.nextInt();
        switch (month) {
        case 1:
            sum = 0;
            break;
        case 2:
            sum = 31;
            break;
        case 3:
            sum = 59;
            break;
        case 4:
            sum = 90;
            break;
        case 5:
            sum = 120;
            break;
        case 6:
            sum = 151;
            break;
        case 7:
            sum = 181;
            break;
        case 8:
            sum = 212;
            break;
        case 9:
            sum = 243;
            break;
        case 10:
            sum = 273;
            break;
        case 11:
            sum = 304;
            break;
        case 12:
            sum = 334;
            break;
        default:
            System.out.println("请输入正确的年，月，日！");
            break;
        }
        sum = sum + day;
        if (month >= 0 && month <= 12 && day >= 1 && day <= 31) {
            if (year % 400 == 0 || year % 4 == 0 && year % 100 != 0) {
                a = 1;
            } else {
                a = 0;
            }
            if (a == 1 && month > 2) {
                sum++;
                System.out.println(year + "年" + month + "月" + day + "号是这一年的第" + sum + "天。");
            } else {
                System.out.println(year + "年" + month + "月" + day + "号是这一年的第" + sum + "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（知识点：循环语句、条件语句）

package book1;

import java.util.Scanner;

public class five04 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入一个四位数");
        int n = sc.nextInt();
        int d = n / 1000;
        int c = n / 100 % 10;
        int b = n / 10 % 10;
        int a = n % 10;
        int s = a * 1000 + b * 100 + c* 10 + d;
        System.out.println("反转后数为" + s);
    }

}