第三次上机练习

/*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 practice3;

public class Code1 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		for (int i = 100; i <= 999; i++){
			int ge = i%10;
			int shi = i/10%10;
			int bai = i/100;
			if (i == ge*ge*ge + shi*shi*shi + bai*bai*bai){
				System.out.println("水仙花数为：" + i);
			}
		}
	}

}

　　

//在控制台输出以下图形（知识点：循环语句、条件语句）
/*(1)1      (2)123456     (3)1 (4)123456
 *   12        12345        21     12345
 *   123       1234        321      1234
 *   1234      123        4321       123
 *   12345     12        54321        12
 *   123456    1        654321         1
 */
package practice3;

public class Code2 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

	//(1)
		for (int i = 1; i <= 6; i++){
			for (int j = 1; j <= i; j++){
				System.out.print(j);				
			}
			System.out.print("
");
		}
	//(2)
		for (int i = 6; i > 0; i--){
			for (int j = 1; j <= i; j++){
				System.out.print(j);
			}
			System.out.print("
");
		}
	//(3)
		for(int i = 1; i < 7; i++) {
            for (int n = 1; n <  7-i; n++) {
                System.out.print(" ");
            }
            for(int j = i; j > 0; j--) {
                System.out.print(j);
            }
            System.out.println();
        }
	//(4)
		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 practice3;

import java.util.Scanner;

public class Code3 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner input = new Scanner(System.in);
        System.out.print("year:");
        int year = input.nextInt();
        System.out.print("month:");
        int month = input.nextInt();
        System.out.print("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 practice3;

import java.util.Scanner;

public class Code4 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner input=new Scanner(System.in);
        System.out.print("input:");
        int a = input.nextInt();
        int b , c , d , e;
        b = a % 10;
        c = a % 100 / 10;
        d = a % 1000 / 100;
        e = a / 1000;
        System.out.println("output:" + b + c + d + e);
	}

}