请编写函数实现并测试运算符重载的方法。 要求： 1、将运算符重载为成员函数，实现复数加实数、复数减实数的功能； 2、将运算符重载为非成员函数，实现实数加复数、实数减法复数的功能； 3、验证上述函数功能的正确性。

好的，我来给你编写这个代码。首先，我们定义一个复数类 `Complex`，并在其中实现加、减、赋值运算符的重载。具体代码如下：

#include <iostream>

using namespace std;

class Complex {
public:
    Complex(double r = 0, double i = 0) : real(r), imag(i) {}
    Complex operator+(double x);
    Complex operator-(double x);
    Complex& operator+=(double x);
    Complex& operator-=(double x);
    friend Complex operator+(double x, const Complex& c);
    friend Complex operator-(double x, const Complex& c);
    void display();
private:
    double real, imag;
};

Complex Complex::operator+(double x) {
    return Complex(real + x, imag);
}

Complex Complex::operator-(double x) {
    return Complex(real - x, imag);
}

Complex& Complex::operator+=(double x) {
    real += x;
    return *this;
}

Complex& Complex::operator-=(double x) {
    real -= x;
    return *this;
}

Complex operator+(double x, const Complex& c) {
    return Complex(c.real + x, c.imag);
}

Complex operator-(double x, const Complex& c) {
    return Complex(x - c.real, -c.imag);
}

void Complex::display() {
    cout << "(" << real << ", " << imag << "i)" << endl;
}

然后，我们来测试一下这个类的运算符重载是否正确：

int main() {
    Complex c1(1, 2), c2;
    c2 = c1 + 3;
    c2.display();
    c2 = c1 - 3;
    c2.display();
    c2 += 3;
    c2.display();
    c2 -= 3;
    c2.display();
    c2 = 3 + c1;
    c2.display();
    c2 = 3 - c1;
    c2.display();
    return 0;
}

输出结果为：

(4, 2i)
(-2, 2i)
(1, 2i)
(-2, 2i)
(4, 2i)
(2, -2i)

可以看到，运算符重载的结果是正确的。