2023.7.14

 1 2023.7.14 周五
 2 //递归:适用于基数bi'ji
 3 public class test
 4 {
 5     public static void main(String[] args)
 6     {
 7 
 8        System.out.println(f(5));
 9     }
10     public static int f(int n)
11     {
12         if(n == 1)
13         {
14             return 1;
15         }
16         else
17         {
18             return n*f(n-1);
19         }
20     }
21 }
22 import java.util.Scanner;
23 //简单计算器（加减乘除）
24 public class test {
25     public static void main(String[] args)
26     {
27         double a = 0.0;
28         double b = 0.0;
29         double ret = 0.0;
30         Scanner scanner = new Scanner(System.in);
31         System.out.println("请输入第一个数：");
32         a = scanner.nextDouble();
33         System.out.println("请输入运算符：");
34         String c = scanner.next();
35         System.out.println("请输入第二个数：");
36         b = scanner.nextDouble();
37         switch(c)
38         {
39             case "+":
40                 ret = jia(a,b);
41                 System.out.println(a+"+"+b+"="+ret);
42                 break;
43             case "-":
44                 ret = jian(a,b);
45                 System.out.println(a+"-"+b+"="+ret);
46                 break;
47             case "*":
48                 ret = cheng(a,b);
49                 System.out.println(a+"*"+b+"="+ret);
50                 break;
51             case "/":
52                 ret = chu(a,b);
53                 System.out.println(a+"/"+b+"="+ret);
54                 break;
55             default:
56                 System.out.println("输入有误");
57                 break;
58         }
59         scanner.close();
60     }
61     public static double jia(double m,double n)
62     {
63         return m+n;
64     }
65     public static double jian(double m,double n)
66     {
67         return m-n;
68     }
69     public static double cheng(double m,double n)
70     {
71         return m*n;
72     }
73     public static double chu(double m,double n)
74     {
75         return m/n;
76     }
77 }