2020.4.2作业（上机）

1.打印出水仙花数

package work;

public class Five1 {

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

    }

}

2.在控制台输出以下图形（知识点：循环语句、条件语

第一个

package work;

public class Five2 {

    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("");
        }

    }

}

第二个

package work;

public class Five3 {

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

    }

}

第三个

package work;

public class Five4 {

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

第四个

package work;

public class Five4 {

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

import java.util.Scanner;

public class Five5 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("year");
        int year = input.nextInt();
        System.out.println("month");
        int month = input.nextInt();
        System.out.println("day");
        int day = input.nextInt();
        int total = 0;
        for (int i = 1; i < month; i++) {
            switch (i) {
            case 4:
            case 6:
            case 9:
            case 11:
                total += 30;
                break;
            case 2:
                if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
                    total += 29;
                else
                    total += 28;
                break;
            default:
                total += 31;
                break;
            }
        }
        total += day;
        System.out.println("该天是第" + total + "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 work;

import java.util.Scanner;

public class Five6 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        System.out.println("输入一位四位数");
        int i = input.nextInt();
         if(i>=1000&&i<10000){
             int ge = i%10;
             int shi = i%100/10;
             int bai = i%1000/100;
             int qian = i/1000;
             System.out.println(ge+""+shi+""+bai+""+qian);
         }else{
             System.out.println("NO!");
         }

    }

}