关于#c++#的问题，如何解决？

从键盘上输入一个复数的实数部分与虚数部分，计算它与另个一个复数的差并输出。
主函数如下图所示，请你创建复数类，写出运算符重载的程序。
注意：
（1）实部与虚部均为0时，只输出实部；
（2）实部为0，虚部不为0时，只输出虚部；
（3）实部不为0，虚部为0时，只输出实部；

#include <iostream>
using namespace std;

class Complex {
public:
    Complex(double a = 0, double b = 0);
    Complex operator-(const Complex& c);
    friend ostream& operator<<(ostream& os, const Complex& c);
    void show(); 

private:
    double real;
    double imag;
};

Complex::Complex(double a, double b) : real(a), imag(b) {}

Complex Complex::operator-(const Complex& c) {
    return Complex(real - c.real, imag - c.imag);
}
/*
（1）实部与虚部均为0时，只输出实部；
（2）实部为0，虚部不为0时，只输出虚部；
（3）实部不为0，虚部为0时，只输出实部；
*/
ostream& operator<<(ostream& os, const Complex& c) {
    if (c.imag == 0) {
        os << c.real;
    } else if (c.real == 0) {
        os << c.imag << "i";
    } else {
        os << c.real << '+' << c.imag << "i";
    }
    return os;
}
void Complex::show() {
    cout<<*this<<endl;
}
int main() {
    double real, imag;
    cin>>real>>imag;
    Complex c1(real,imag),c2(3.14,2.72),c3;
    c3 = c1 - c2;
    c3.show(); 

    return 0;
}

#include <iostream>
#include <cmath>
using namespace std;

class Complex 
{
public:
    Complex(double r = 0, double i = 0) : real(r), imag(i) {}
    Complex operator-(const Complex& c) const {
        return Complex(real - c.real, imag - c.imag);
    }
    void show() const {
        if (real == 0 && imag == 0) {
            cout << "0" << endl;
        } else if (real == 0) {
            cout << imag << "i" << endl;
        } else if (imag == 0) {
            cout << real << endl;
        } else {
            if (imag < 0)
                cout << real << imag << "i" << endl;
            else
                cout << real << "+" << imag << "i" << endl;
        }
    }
private:
    double real;
    double imag;
};