2023.7.14

2023.7.14 周五
//递归:适用于基数bi'ji
public class test
{
    public static void main(String[] args)
    {

       System.out.println(f(5));
    }
    public static int f(int n)
    {
        if(n == 1)
        {
            return 1;
        }
        else
        {
            return n*f(n-1);
        }
    }
}
import java.util.Scanner;
//简单计算器（加减乘除）
public class test {
    public static void main(String[] args)
    {
        double a = 0.0;
        double b = 0.0;
        double ret = 0.0;
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入第一个数：");
        a = scanner.nextDouble();
        System.out.println("请输入运算符：");
        String c = scanner.next();
        System.out.println("请输入第二个数：");
        b = scanner.nextDouble();
        switch(c)
        {
            case "+":
                ret = jia(a,b);
                System.out.println(a+"+"+b+"="+ret);
                break;
            case "-":
                ret = jian(a,b);
                System.out.println(a+"-"+b+"="+ret);
                break;
            case "*":
                ret = cheng(a,b);
                System.out.println(a+"*"+b+"="+ret);
                break;
            case "/":
                ret = chu(a,b);
                System.out.println(a+"/"+b+"="+ret);
                break;
            default:
                System.out.println("输入有误");
                break;
        }
        scanner.close();
    }
    public static double jia(double m,double n)
    {
        return m+n;
    }
    public static double jian(double m,double n)
    {
        return m-n;
    }
    public static double cheng(double m,double n)
    {
        return m*n;
    }
    public static double chu(double m,double n)
    {
        return m/n;
    }
}