如何在c ++中编写此代码

#include<iostream>

int main() {
    char op;
    double num1, num2;

    std::cout << "请输入第一个数字：";
    std::cin >> num1;
    std::cout << "请输入运算符（+、-、*、/）：";
    std::cin >> op;
    std::cout << "请输入第二个数字：";
    std::cin >> num2;

    switch (op) {
        case '+':
            std::cout<< num1 << " + "<< num2 << " = "<< num1 + num2<< std::endl;
            break;
        case '-':
            std::cout<< num1 << " - "<< num2 << " = "<< num1 - num2<< std::endl;
            break;
        case '*':
            std::cout<< num1 << " * "<< num2 << " = "<< num1 * num2<< std::endl;
            break;
        case '/':
            if (num2 != 0) {
                std::cout<< num1 << " / "<< num2 << " = "<< num1 / num2<< std::endl;
            } else {
                std::cout << "除数不能为零！"<< std::endl;
            }
            break;
        default:
            std::cout << "无效的运算符！"<< std::endl;
            break;
    }

    return 0;
}