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 }
