C++编程,定义一个复数类

//complex类#include#includeclass complex{double real,imag;public:complex(){real=5;imag=5;}//缺省构造函数complex(double r){real=r;imag=0;}//只给实部赋值的构造函数complex(double r,double i){real=r;imag=i;}//同时给实、虚部赋值的函数double displayreal(){return real;}//返回复数实部double displayimag(){return imag;}//返回复数虚部complex operator+(complex c);//实现复数相加complex operator-(complex c);//实现复数相减complex operator*(complex c);//实现复数相乘double cab(complex c);//求复数绝对值（模）complex sqr(complex c);//求复数平方根friend ostream &operato