定义一个复数类,要求能执行“＋”和“－”运算,并能按“a＋bi”的格式显示一个复数.测试这个类.

#include
class complex
{
public:
complex(){real=imag=0;}
complex(double r,double i)
{real=r;imag=i;}
complex operator+(const complex &c);
complex operator-(const complex &c);
friend void print(const complex &c);
private:
double real,imag;
};
inline complex complex ::operator+(const complex &c)
{return complex (real+c.real,imag+c.imag);}
inline complex complex ::operator-(const complex &c)
{return complex (real-c.real,imag-c.imag);};
void print(const complex &c)
{
if(c.imag