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 doom4;
public class thefiveweekclasswork1 {
public static void main(String[] args) {
// TODO Auto-generated method stub
int i = 100;
for (i = 100; i < 1000; i++) {
int ge = i % 10;
int shi = i / 10 % 10;
int bai = i / 100;
if (i == bai * bai * bai + shi * shi * shi + ge * ge * ge)
System.out.println(i + "是一个水仙花数");
}
}
}
2
package doom4;
public class thefiveweekclasswork2_1 {
public static void main(String[] args) {
// TODO Auto-generated method stub
int i;
int j;
for (i = 1; i <= 6; i++) {
for (j = 1; j <= i; j++) {
System.out.print(j);
}
System.out.println();
}
}
}
package doom4;
public class thefiveweekclasswork2_2 {
public static void main(String[] args) {
// TODO Auto-generated method stub
int i;
int j;
for (i = 1; i <= 6; i++) {
for (j = 1; j <= 7 - i; j++) {
System.out.print(j);
}
System.out.println();
}
}
}
package doom4;
public class thefiveweekclasswork2_3 {
public static void main(String[] args) {
// TODO Auto-generated method stub
int i;
int j;
for (i = 1; i <= 6; i++) {
for (j = 1; j <= 7 - i; j++) {
System.out.print(" ");
}
for (j = i; j >= 1; j--)
System.out.print(j);
System.out.println();
}
System.out.println();
}
}
package doom4;
public class thefiveweekclasswork2_4 {
public static void main(String[] args) {
// TODO Auto-generated method stub
int i;
int j;
for (i = 1; i <= 6; i++) {
for (j = 1; j <= i; j++) {
System.out.print(" ");
}
for (j = 1; j <= 7 - 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 doom4;
import java.util.Scanner;
public class thefiveweekclasswork3 {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input = new Scanner(System.in);
System.out.print("请输入一个年份:");
int year = input.nextInt();
System.out.print("请输入一个月份:");
int month = input.nextInt();
System.out.print("请输入一个日:");
int day = input.nextInt();
int sum = 0;
for (int i = 1; i < month; i++) {
switch (i) {
case 2:
if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
sum += 29;
else
sum += 28;
break;
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
sum += 31;
break;
case 4:
case 6:
case 9:
case 11:
sum += 30;
break;
}
}
sum += day;
System.out.println(year + "年" + month + "月" + day + "日" + "是" + year + "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 doom4;
import java.util.Scanner;
public class thefiveweekclasswork4 {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input = new Scanner(System.in);
System.out.print("请输入一个四位数:");
int x = input.nextInt();
int ge = x % 10;
int shi = x / 10 % 10;
int bai = x / 100 % 10;
int qian = x / 1000;
System.out.print(ge);
System.out.print(shi);
System.out.print(bai);
System.out.print(qian);
}
}
