c++复数的四则运算

C++中的复数四则运算可以通过自定义复数类来实现。下面是一个复数类的示例代码，其中包括了加、减、乘、除四种运算：

#include <iostream>
using namespace std;

class Complex {
private:
    double real; // 实部
    double imag; // 虚部
public:
    Complex(double r = 0, double i = 0) : real(r), imag(i) {}
    Complex operator+(const Complex& c2) const { // 加法运算
        return Complex(real + c2.real, imag + c2.imag);
    }
    Complex operator-(const Complex& c2) const { // 减法运算
        return Complex(real - c2.real, imag - c2.imag);
    }
    Complex operator*(const Complex& c2) const { // 乘法运算
        return Complex(real * c2.real - imag * c2.imag, real * c2.imag + imag * c2.real);
    }
    Complex operator/(const Complex& c2) const { // 除法运算
        double denominator = c2.real * c2.real + c2.imag * c2.imag;
        return Complex((real * c2.real + imag * c2.imag) / denominator, (imag * c2.real - real * c2.imag) / denominator);
    }
    bool operator==(const Complex& c2) const { // 判断两个复数是否相等
        return (real == c2.real) && (imag == c2.imag);
    }
    bool operator!=(const Complex& c2) const { // 判断两个复数是否不相等
        return !(*this == c2);
    }
    friend ostream& operator<<(ostream& os, const Complex& c); // 重载输出运算符
};

ostream& operator<<(ostream& os, const Complex& c) {
    os << c.real << "+" << c.imag << "i";
    return os;
}

int main() {
    Complex a(1, 2);
    Complex b(3, 4);
    Complex c = a + b;
    Complex d = a - b;
    Complex e = a * b;
    Complex f = a / b;
    cout << "a = " << a << endl;
    cout << "b = " << b << endl;
    cout << "a + b = " << c << endl;
    cout << "a - b = " << d << endl;
    cout << "a * b = " << e << endl;
    cout << "a / b = " << f << endl;
    if (a == b) {
        cout << "a == b" << endl;
    }
    if (a != b) {
        cout << "a != b" << endl;
    }
    return 0;
}