c++用运算符重载设计复数类，实现复数的+、-、*、/运算。

在 C++ 中，可以利用运算符重载（operator overloading）来设计复数类（Complex），使得我们可以像操作普通数值一样直接对复数进行加减乘除等操作。首先，我们创建一个名为 Complex 的结构体或类，包含两个成员变量代表实部（real）和虚部（imaginary）。然后，我们定义运算符重载函数，分别对应四种基本算术运算：

class Complex {
public:
    double real, imag;

    // 构造函数
    Complex(double r = 0.0, double i = 0.0) : real(r), imag(i) {}

    // 运算符重载 - 加法
    Complex operator+(const Complex& other) const {
        return Complex(real + other.real, imag + other.imag);
    }

    // 运算符重载 - 减法
    Complex operator-(const Complex& other) const {
        return Complex(real - other.real, imag - other.imag);
    }

    // 运算符重载 - 乘法
    Complex operator*(const Complex& other) const {
        double newReal = real * other.real - imag * other.imag;
        double newImag = real * other.imag + imag * other.real;
        return Complex(newReal, newImag);
    }

    // 运算符重载 - 除法
    Complex operator/(const Complex& other) const {
        double denominator = other.real * other.real + other.imag * other.imag;
        if (denominator == 0)
            throw std::runtime_error("Division by zero is not allowed for complex numbers.");
        double newReal = (real * other.real + imag * other.imag) / denominator;
        double newImag = (imag * other.real - real * other.imag) / denominator;
        return Complex(newReal, newImag);
    }
};

// 使用示例
int main() {
    Complex a(1, 2);
    Complex b(3, 4);

    Complex sum = a + b;     // a + b 的结果
    Complex diff = a - b;    // a - b 的结果
    Complex product = a * b;   // a * b 的结果
    Complex quotient = a / b; // a / b 的结果

    return 0;
}