JavaHomeWorkList

3.17 关键词：剪刀石头布；随机数

 1 import java.util.Scanner;
 2 public class JSB {
 3     public static void main(String[] args) {
 4         int a = (int)(Math.random() * 3);
 5         Scanner input = new Scanner(System.in);
 6         System.out.println("输入0（剪刀）/1（石头）/2（布）：");
 7         int x = input.nextInt();
 8
 9         if (x != 0 && x != 1 && x != 2)
10             System.out.println("请输入0/1/2！");
11         else {
12             if (a == 0 && x == 2)
13                 System.out.println("电脑是剪刀，你是布，电脑赢！");
14             if (a == 1 && x == 0)
15                 System.out.println("电脑是石头，你是剪刀，电脑赢！");
16             if (a == 2 && x == 1)
17                 System.out.println("电脑是布，你是石头，电脑赢！");
18             if (a == 0 && x == 1)
19                 System.out.println("电脑是剪刀，你是石头，你赢！");
20             if (a == 1 && x == 2)
21                 System.out.println("电脑是石头，你是布，你赢！");
22             if (a == 2 && x == 0)
23                 System.out.println("电脑是布，你是剪刀，你赢！");
24             if (a == x)
25                 System.out.println("平手！");
26             System.out.println("电脑是：" + a);
27         }
28         input.close();
29     }
30
31 }

3.16 关键词：矩形；随机坐标；中心点（0，0）、宽100、高200

1 public class rectangle {
2     public static void main(String[] args) {
3         int x = (int)(Math.random() * 101 - 50);
4         int y = (int)(Math.random() * 201 - 100);
5         System.out.println("矩形内随机坐标为：" + "(" + x + " , " + y + ")");
6
7     }
8
9 }

3.14 关键词：硬币；正面；反面；0；1

 1 import java.util.Scanner;
 2 public class guesscoin {
 3     public static void main(String[] args) {
 4         int coin = (int)(Math.random() * 2);
 5         Scanner input = new Scanner(System.in);
 6         System.out.println("输入0或1，1代表正面，0代表反面：");
 7         int guess = input.nextInt();
 8
 9         if (guess != 0 && guess != 1)
10             System.out.println("请输入0或1！");
11         else {
12             if (guess == coin)
13             System.out.println("猜对了！");
14             else
15                 System.out.println("猜错了！");
16             System.out.println("硬币数字为：" + coin + " ；* 1代表正面，0代表反面");
17              }
18         input.close();
19     }
20 }

3.9 关键词：ISBN-10；检验和

 1 import java.util.*;
 2 public class ISBN10 {
 3     public static void main(String[] args) {
 4         Scanner input = new Scanner(System.in);
 5         System.out.println("输入9个数字：");
 6
 7         int d1 = input.nextInt();
 8         int d2 = input.nextInt();
 9         int d3 = input.nextInt();
10         int d4 = input.nextInt();
11         int d5 = input.nextInt();
12         int d6 = input.nextInt();
13         int d7 = input.nextInt();
14         int d8 = input.nextInt();
15         int d9 = input.nextInt();
16
17         int sum = (int)(d1 * Math.pow(10, 8) + d2 * Math.pow(10, 7) + d3 * Math.pow(10, 6) + d4 * Math.pow(10, 5) + d5 * Math.pow(10, 4) + d6 * Math.pow(10, 3) + d7 * Math.pow(10, 2) + d8 * Math.pow(10, 1) + d9);
18
19         int d10 = (d1 * 1 + d2 * 2 + d3 * 3 + d4 * 4 + d5 * 5 + d6 * 6 + d7 * 7 + d8 * 8 + d9 * 9) % 11;
20         System.out.println("校验和为： " + d10);
21
22         if (d1 == 0)
23             if (d10 == 10)
24                 System.out.println("ISBN-10为：" + "0" + sum + "X");
25             else
26                 System.out.println("ISBN-10为：" + "0" + sum + d10);
27         else
28             System.out.println("ISBN-10为：" + sum * 10 + d10);
29         input.close();
30
31     }
32
33 }

3.8 关键词：非降序

 1 import java.util.*;
 2 public class NodescendingOeder {
 3     public static void main(String[] args) {
 4         Scanner input = new Scanner(System.in);
 5         System.out.println("输入三个整数：");
 6         int num1 = input.nextInt();
 7         int num2 = input.nextInt();
 8         int num3 = input.nextInt();
 9         /*非降序列：通常非降序列的元素定义在有序域上，每一项不小于它的前一项。非降序列通常指无穷序列。
10         例如：定义在实数域上的非降序列 1,2,3,4,5,...6
11         非降序列每项不一定严格大于它的前一项，例如 1,1,1,1,1,...
12         */
13         if (num1 < num2) {
14             if (num1 < num3) {
15                 System.out.print(num1);
16                 if (num2 < num3)
17                     System.out.print(" " + num2 + " " + num3);
18                 else
19                     System.out.print(" " + num3 + " " + num2);
20                 }
21             else
22                 System.out.print(num3 + " " + num1 + " " + num2);
23         }
24         else if (num1 < num3)
25                 System.out.print(num2 + " " + num1 + " " + num3);
26                 else if (num2 < num3)
27                     System.out.print(num2 + " " + num3 + " " + num1);
28                 else
29                     System.out.print(num3 + " " + num2 + " " + num1);
30         input.close();
31     }
32 }

3.5 关键词：找到将来的日期

 1 import java.util.*;
 2 public class FindFutureDay {
 3     public static void main(String[] args) {
 4         Scanner input = new Scanner(System.in);
 5         System.out.println("输入一个数字，周日是0，周一是1，... 周六是6 ");
 6         int day0 = input.nextInt();
 7         System.out.println("输入一个数字，表示天数： ");
 8         int day1 = input.nextInt();
 9         int futureday = ( day0 + day1 ) % 7;
10         //System.out.println("Today is " + day0 + " Futureday is " + futureday); 这个语句太粗糙！！！
11         switch (day0) {
12           case 0: System.out.print("Today is Sunday and the future day is "); break;
13           case 1: System.out.print("Today is Monday and the future day is "); break;
14           case 2: System.out.print("Today is Tuesday and the future day is "); break;
15           case 3: System.out.print("Today is Wendesday and the future day is "); break;
16           case 4: System.out.print("Today is Thursday and the future day is "); break;
17           case 5: System.out.print("Today is Friday and the future day is "); break;
18           case 6: System.out.print("Today is Saturday and the future day is ");
19         }
20
21         switch (futureday) {
22         case 0: System.out.print("Sunday "); break;
23         case 1: System.out.print("Monday "); break;
24         case 2: System.out.print("Tuesday "); break;
25         case 3: System.out.print("Wendesday "); break;
26         case 4: System.out.print("Thursday "); break;
27         case 5: System.out.print("Friday "); break;
28         case 6: System.out.print("Saturday ");
29         }
30         //双重switch语句
31         input.close();
32
33     }
34
35 }

3.11 关键词：一个月的总天数

 1 import java.util.*;
 2 public class DaysOfMonth {
 3     public static void main(String[] args) {
 4         // TODO Auto-generated method stub
 5         Scanner input = new Scanner(System.in);
 6         System.out.println("Enter a month and a year: ");
 7         int month = input.nextInt();
 8         int year = input.nextInt();
 9
10         /*if (month ==2)
11             if ((year % 4 == 0 && year % 100 != 0) || year % 400 ==0)
12                 System.out.println("February of " + year + " has" + " 29 days ");
13             else
14                 System.out.println("February " + year + " has" + " 28 days ");
15         else if (month == 1 ||month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12)
16             System.out.println(month + " of " + year + " has 31 days ");
17         else
18             System.out.println(month + " of " + year + " has 30 days ");
19             */
20         if ((year % 4 == 0 && year % 100 != 0) || year % 400 ==0)
21             switch(month) {
22               case 1:System.out.println("Jan. " + year + " has 31 days."); break;
23               case 2:System.out.println("Feb. " + year + " has 29 days."); break;
24               case 3:System.out.println("Mar. " + year + " has 31 days."); break;
25               case 4:System.out.println("Apr. " + year + " has 30 days."); break;
26               case 5:System.out.println("May. " + year + " has 31 days."); break;
27               case 6:System.out.println("Jun. " + year + " has 30 days."); break;
28               case 7:System.out.println("Jul. " + year + " has 31 days."); break;
29               case 8:System.out.println("Aug. " + year + " has 31 days."); break;
30               case 9:System.out.println("Sep. " + year + " has 30 days."); break;
31               case 10:System.out.println("Oct. " + year + " has 31 days."); break;
32               case 11:System.out.println("Nov. " + year + " has 30 days."); break;
33               case 12:System.out.println("Dec. " + year + " has 31 days.");
34             }
35         else
36             switch(month) {
37             case 1:System.out.println("Jan. " + year + " has 31 days."); break;
38               case 2:System.out.println("Feb. " + year + " has 28 days."); break;
39               case 3:System.out.println("Mar. " + year + " has 31 days."); break;
40               case 4:System.out.println("Apr. " + year + " has 30 days."); break;
41               case 5:System.out.println("May. " + year + " has 31 days."); break;
42               case 6:System.out.println("Jun. " + year + " has 30 days."); break;
43               case 7:System.out.println("Jul. " + year + " has 31 days."); break;
44               case 8:System.out.println("Aug. " + year + " has 31 days."); break;
45               case 9:System.out.println("Sep. " + year + " has 30 days."); break;
46               case 10:System.out.println("Oct. " + year + " has 31 days."); break;
47               case 11:System.out.println("Nov. " + year + " has 30 days."); break;
48               case 12:System.out.println("Dec. " + year + " has 31 days.");
49             }
50           input.close();
51     }
52
53 }

练习题，关键词：彩票

 1 import java.util.Scanner;
 2 public class caipiao {
 3     public static void main(String[] args) {
 4         int cp = (int)(Math.random() * 100);//获取一个两位数的数字作为彩票号码
 5
 6         Scanner input = new Scanner(System.in);
 7         System.out.println("输入你猜测的彩票号码：");
 8         int guess = input.nextInt();
 9
10         int cp1 = cp / 10;
11         int cp2 = cp % 10;
12
13         int guess1 = guess / 10;
14         int guess2 = guess % 10;
15
16         System.out.println("彩票号码是：" + cp);
17
18         if (guess == cp)
19             System.out.println("恭喜你猜对了，你将获得100元！");
20         else if (guess1 == cp2 && guess2 == cp2)
21             System.out.println("数字对了，顺序不对，你将获得50元！");
22         else if (guess1 == cp1 || guess1 == cp2 || guess2 == cp1 || guess2 == cp2)
23             System.out.println("猜对了一个数字，你将获得30元！");
24         else
25             System.out.println("很遗憾，你没有猜对！");
26         input.close();
27
28     }
29
30 }