用运算符重载设计复数类，实现复数的+、-、*、/运算。

好的，以下是一个使用运算符重载设计的复数类的示例代码：

#include <iostream>
using namespace std;

class Complex {
public:
    Complex(double real = 0.0, double imag = 0.0) {
        m_real = real;
        m_imag = imag;
    }

    // 重载加号运算符
    Complex operator+(const Complex& other) const {
        return Complex(m_real + other.m_real, m_imag + other.m_imag);
    }

    // 重载减号运算符
    Complex operator-(const Complex& other) const {
        return Complex(m_real - other.m_real, m_imag - other.m_imag);
    }

    // 重载乘号运算符
    Complex operator*(const Complex& other) const {
        return Complex(m_real * other.m_real - m_imag * other.m_imag,
                       m_real * other.m_imag + m_imag * other.m_real);
    }

    // 重载除号运算符
    Complex operator/(const Complex& other) const {
        double denominator = other.m_real * other.m_real + other.m_imag * other.m_imag;
        return Complex((m_real * other.m_real + m_imag * other.m_imag) / denominator,
                       (m_imag * other.m_real - m_real * other.m_imag) / denominator);
    }

    // 重载输出运算符
    friend ostream& operator<<(ostream& os, const Complex& c) {
        os << c.m_real << " + " << c.m_imag << "i";
        return os;
    }

private:
    double m_real;
    double m_imag;
};

int main() {
    Complex a(1, 2);
    Complex b(3, 4);

    cout << "a = " << a << endl;
    cout << "b = " << b << endl;

    Complex c = a + b;
    cout << "a + b = " << c << endl;

    Complex d = a - b;
    cout << "a - b = " << d << endl;

    Complex e = a * b;
    cout << "a * b = " << e << endl;

    Complex f = a / b;
    cout << "a / b = " << f << endl;

    return 0;
}

在这个示例代码中，我们定义了一个名为 Complex 的类，它有两个私有成员变量：m_real 和 m_imag，分别表示复数的实部和虚部。

然后，我们重载了加号、减号、乘号和除号运算符，以便在程序中使用 +、-、* 和 / 运算符对复数进行运算。

此外，我们还重载了输出运算符 <<，以便在程序中使用 cout 输出 Complex 对象。

在 main 函数中，我们创建了两个复数对象 a 和 b，并使用重载的运算符对它们进行加、减、乘、除运算，然后将结果输出到屏幕上。