哪位大神能帮忙看看下边的空格里该填写什么。。

Question

#include <iostream.h>class Complex{public: Complex(){real=0;imag=0;} Complex(double r){real=r;imag=0;} Complex(double r,double i){real=r;imag=i;} friend Complex operator+ (Complex &c1,Complex &c2); _____________private: _____________ double imag;};Complex operator+ (Complex &c1,Complex &c2){return Complex(c1.real+c2.real, c1.imag+c2.imag);}void Complex::display(){cout<<"("<<real<<","<<imag<<"i)"<<endl;}int main(){ int a,b,c,d; cin>>a>>b>>c>>d; Complex c1(a,b),c2(c,d),c3; c3=c1+c2; cout<<"c1="; c1.display(); cout<<"c2="; c2.display(); cout<<"c1+c2="; c3.display(); return 0;}

Answer 1

void display();

double real;

Answer 2

说的不是你

Answer 3

什么鬼程序