定义一个复数类Complex，重载运算符“+”，使之能用于复数的加法运算。将运算符函数重载为非成员、非友元的普通函数。编写程序，求两个复数之和。

两个复数

复数之和

3 4
5 -10

(8.00,-6.00i)
#include <iostream> 
#include <iomanip> 
using namespace std; 
class Complex 
{ 
public: 
    Complex(); 
    Complex(double r,double i); 
    double get_real(); 
    double get_imag(); 
    void display(); 
private: 
    double real; 
    double imag; 
}; 
Complex::Complex()  
{  
    return;  
}  
Complex::Complex(double r,double i)  
{  
    real=r;imag=i;  
}  
double Complex::get_real()  
{  
    return real;  
}  
double Complex::get_imag()  
{  
    return imag;  
}  
void Complex::display()  
{  
    cout<<"("<<real<<","<<imag<<"i)"<<endl;  
}  
Complex operator +(Complex a,Complex b)  
{  
    double i,j;  
    i=a.get_real() +b.get_real();  
    j=a.get_imag() +b.get_imag();  
    Complex c(i,j);  
    return c;  
}  
  
int main() 
{ 
    double real,imag; 
    cin>>real>>imag; 
    Complex c1(real,imag); 
    cin>>real>>imag; 
    Complex c2(real,imag); 
    Complex c3=c1+c2; 
    cout<<setiosflags(ios::fixed); 
    cout<<setprecision(2); 
    c3.display(); 
    return 0; 
}