import java.util.Scanner;

public class Calculator {
    // 加法
    public static double add(double num1, double num2) {
        return num1 + num2;
    }


    // 减法
    public static double subtract(double num1, double num2) {
        return num1 - num2;
    }

    // 乘法
    public static double multiply(double num1, double num2) {
        return num1 * num2;
    }

    // 除法
    public static double divide(double num1, double num2) {
        if (num2 == 0) {
            throw new IllegalArgumentException("除数不能为零");
        }
        return num1 / num2;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入第一个数字:");
        double num1 = scanner.nextDouble();

        System.out.println("请输入第二个数字:");
        double num2 = scanner.nextDouble();

        System.out.println("请选择操作 (+, -, *, /):");
        String operator = scanner.next();

        double result;
        switch (operator) {
            case "+":
                result = add(num1, num2);
                break;
            case "-":
                result = subtract(num1, num2);
                break;
            case "*":
                result = multiply(num1, num2);
                break;
            case "/":
                try {
                    result = divide(num1, num2);
                } catch (IllegalArgumentException e) {
                    System.out.println(e.getMessage());
                    return;
                }
                break;
            default:
                System.out.println("无效的操作符");
                return;
        }

        System.out.println("结果: " + num1 + " " + operator + " " + num2 + " = " + result);
        scanner.close();
    }
}

//hhhh