#include <iostream>

 #include <string>

 using namespace std;

 /*运算符重载可以通过类的成员函数和友元函数两种途径来实现*/

 class complex

 {

     public:

         complex(int x=,int y=)

         {

             real = x;

             image = y;

         }

         ~complex(){}

         void show()

         {

             if(image >= )

                 cout<<real<<"+"<<image<<"i"<<endl;

             else

                 cout<<real<<image<<"i"<<endl;

         }

         /*重载双目运算符*/

         complex operator +(const complex& a);

         complex operator -(const complex& a);

         /*重载单目运算符*/

         complex operator ++(); //原本为一个参数，但是少一个参数就没有参数了。

         complex operator ++(int);

     private:

         int real,image;

 };

 /*注意：以成员函数的形式来重载运算符，此时参数要比原本的参数少一个，因为在非静态成员函数中有this指针访问该对象*/

 /*但是如果是用友元函数来实现运算符重载，那么运算符函数的参数个数就是操作数的个数*/

 complex complex::operator +(const complex& a)

 {

     return complex(real+a.real,image+a.image);

 }

 complex complex::operator -(const complex& a)

 {

     complex c;

     c.real = real - a.real;

     c.image = image - a.image;

     return c;

 }

 /*默认为不带参数为前置运算符，带参数int为后置运算符重载*/

 complex complex::operator ++()  //前置++

 {

     complex c;

     real++;

     image++;

     c.real = real;

     c.image = image;

     return c;

 }

 complex complex::operator ++(int) //后置++

 {

     complex c;

     c.real = real;

     c.image = image;

     real++;

     image++;

     return c;

 }

 /*之前对为什么可以直接调用complex类型的对象的私有变量表示疑惑，我个人理解是可以在complex的成员函数中调用任何complex类的对象的私有变量*/

 int main()

 {

     complex a1(,);

     complex a2(,);

     complex c1,c2,c3,c4;

     c1 = a1 + a2;

     c2 = a1 - a2;

     c3 = ++c1;

     c4 = c2++;

     c1.show();

     c2.show();

     c3.show();

     c4.show();

     return ;

 }