定义一个复数类，通过重载运算符：”+”、”-”和”*”为复数类的成员函数，直接 实现两个复数之间的运算。编写一个完整的程序包括主函数测试。

#include
using namespace std;
class Complex {
private:
	double real;
	double image;
public:
	Complex()
	{
		real = 0;
		image = 0;
	}
	Complex(double a, double b)
	{
		real = a;
		image = b;
	}
	Complex operator+(const Complex &c)
	{
		/*Complex tmp;
		tmp.real = real + c.real;
		tmp.image = image + c.image;
		return tmp;*/
		real = real + c.real;
		image = image + c.image;
		return *this;

	}
	Complex operator-(const Complex &c)const
	{
		Complex tmp;
		tmp.real = real - c.real;
		tmp.image = image - c.image;
		return tmp;
	}
	Complex operator*(const Complex &c)const
	{
		Complex tmp;
		tmp.real = real*c.real - image*c.image;
		tmp.image = image*c.real + real*c.image;
		return tmp;
	}
	void show()
	{
		cout << real << "+" << image << "i" << endl;
	}
};
int main()
{
	Complex c1(2, 3);
	Complex c2(1, 1);
	Complex c3;
	c1.show();
	c2.show();
	(c1 + c2).show();
	c3 = c1 + c2;
	c3.show();
	return 0;

}