第五周上机练习
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）
1 package pro1; 2 import java.util.Scanner; 3 public class test { 4 public static void main(String[] args) { 5 for (int i = 100; i < 1000; i++) { 6 int ge = i % 10; 7 int shi = i % 100 / 10; 8 int bai = i / 100; 9 if (ge * ge * ge + shi * shi * shi + bai * bai * bai == i) { 10 System.out.println(i); 11 } 12 } 13 } 14 }
2.在控制台输出以下图形（知识点：循环语句、条件语句）
1 package pro1; 2 import java.util.Scanner; 3 public class test { 4 public static void main(String[] args) { 5 for(int i=1;i<=6;i++){ 6 for(int j=1;j<=i;j++){ 7 System.out.print(j); 8 } 9 System.out.println(); 10 } 11 } 12 }
1 package pro1; 2 import java.util.Scanner; 3 public class test { 4 public static void main(String[] args) { 5 for(int i=6;i>=0;i--){ 6 for(int j=1;j<=i;j++){ 7 System.out.print(j); 8 } 9 System.out.println(); 10 } 11 } 12 }
1 package pro1; 2 import java.util.Scanner; 3 public class test { 4 public static void main(String[] args) { 5 for(int i=1;i<7;i++) { 6 for (int k = 1; k <=6-i ; k++) { 7 System.out.print(" "); 8 } 9 for(int j=i;j>0;j--) { 10 System.out.print(j); 11 } 12 System.out.println(); 13 } 14 } 15 }
1 package pro1; 2 import java.util.Scanner; 3 public class test { 4 public static void main(String[] args) { 5 for(int i = 6;i >= 1;i--) { 6 for(int k = 0;k < 6-i;k++) { 7 System.out.print(" "); 8 } 9 for(int j = 1;j <= i;j++) { 10 System.out.print(j); 11 } 12 System.out.println(""); 13 14 } 15 } 16 }
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）
1 package pro1; 2 import java.util.Scanner; 3 public class test { 4 public static void main(String[] args) { 5 int year,month,day,sum=0,eryue=28; 6 Scanner in = new Scanner(System.in); 7 System.out.print("请输入年份:"); 8 year = in.nextInt(); 9 System.out.print("请输入月份:"); 10 month = in.nextInt(); 11 System.out.print("请输入几号:"); 12 day = in.nextInt(); 13 if((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) 14 { 15 eryue = 29; 16 } 17 switch(month) 18 { 19 case 1: 20 sum = day; 21 break; 22 case 2: 23 sum = 31 + day; 24 break; 25 case 3: 26 sum = 31+eryue+day; 27 break; 28 case 4: 29 sum = 31+eryue+31+day; 30 break; 31 case 5: 32 sum = 31+eryue+31+30+day; 33 break; 34 case 6: 35 sum = 31+eryue+31+30+31+day; 36 break; 37 case 7: 38 sum = 31+eryue+31+30+31+30+day; 39 break; 40 case 8: 41 sum = 31+eryue+31+30+31+30+31+day; 42 break; 43 case 9: 44 sum = 31+eryue+31+30+31+30+31+31+day; 45 break; 46 case 10: 47 sum = 31+eryue+31+30+31+30+31+31+30+day; 48 break; 49 case 11: 50 sum = 31+eryue+31+30+31+30+31+31+30+31+day; 51 break; 52 case 12: 53 sum = 31+eryue+31+30+31+30+31+31+30+31+30+day; 54 } 55 System.out.println(year+" 年 "+month+" 月 " + day + "号是当年的第"+sum+"天"); 56 } 57 }
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）
1 package pro1; 2 import java.util.Scanner; 3 public class test { 4 public static void main(String[] args) { 5 Scanner aaa = new Scanner(System.in); 6 System.out.println("请输入一个数："); 7 int x = aaa.nextInt(); 8 if(x >= 1000 && x < 10000){ 9 int ge = x % 10; 10 int shi = x % 100 / 10; 11 int bai = x % 1000 / 100; 12 int qian = x / 1000; 13 int sum = qian + bai*10 +shi*100 +ge*1000; 14 System.out.println(sum); 15 } 16 } 17 }
