题解 | #简单计算器#

import java.util.Scanner;
public class Main {
    
    public static void main(String[] args) {
        
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        if(str.contains("+")) {
            String[] s = str.split("\\+");
            double a = Double.parseDouble(s[0]);
            double b = Double.parseDouble(s[1]);
            System.out.printf("%.4f+%.4f=%.4f",a,b,a+b);
        } else if(str.contains("-")) {
            String[] s = str.split("-");
            double a = Double.parseDouble(s[0]);
            double b = Double.parseDouble(s[1]);
            System.out.printf("%.4f-%.4f=%.4f",a,b,a-b);
        } else if(str.contains("*")) {
            String[] s = str.split("\\*");
            double a = Double.parseDouble(s[0]);
            double b = Double.parseDouble(s[1]);
            System.out.printf("%.4f*%.4f=%.4f",a,b,a*b);
        } else if(str.contains("/")) {
            String[] s = str.split("/");
            double a = Double.parseDouble(s[0]);
            double b = Double.parseDouble(s[1]);
            if(b == 0) {
                System.out.println("Wrong!Division by zero!");
            } else {
                System.out.printf("%.4f/%.4f=%.4f",a,b,a/b);
            }
        } else {
            System.out.println("Invalid operation!");
        }
    }
}