#include <iostream> using namespace std; class Complex { public: Complex();//此函数必须定义 Complex(double r,double i); friend Complex operator+(Complex &c1,Complex &c2); void display(); private: double real,imag; }; Complex::Complex() {} Complex::Complex(double r,double i) { real=r; imag=i; } 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() { double cr1,ci1,cr2,ci2; cin>>cr1>>ci1>>cr2>>ci2; Complex c1(cr1,ci1),c2(cr2,ci2),c3; c3=c1+c2; c3.display(); return 0; }