定义一个复数类,实部和虚部都是整数类型,用成员函数形式重载复数的“+”运算,用友元函数的形式重载 “

class complex
{
int real;
int img;
public:
complex( int _real,int _img ) { real = _real; img = _img; }
complex & operator + ( complex & x )
{
real += x.real;
img += x.img;
}
};