複數是一個數學中很重要的東西，下面是我用c++實現的複數的類

#define _CRT_SECURE_NO_WARNINGS

#include <iostream>
using namespace std;
#include <cstdlib>

class Plural
{
public:
	Plural(int real = 0, int image = 0)     // 建構函式
		: _real(real)
		, _image(image)
	{ }
	~Plural()                               //解構函式
	{ }
	Plural(const Plural &num)               //拷貝建構函式
	{
		_real = num._real;
		_image = num._image;
	}
	bool operator>(const Plural& num)        //大於號的過載
	{
		if (_image == 0 && num._image == 0)
		{
			if (_real > num._real)
			{
				return true;
			}
			else
			{
				return false;
			}
		}
		else
		{
			return false;
		}
	}
	bool operator<(const Plural& num)            //小於號的過載
	{
		if (_image == 0 && num._image == 0)
		{
			if (_real < num._real)
			{
				return true;
			}
			else
			{
				return false;
			}
		}
		else
		{
			return false;
		}
	}
	bool operator=(const Plural& num)                //複製運算子的過載
	{
		if (_real == num._real && _image == num._image)
		{
			return true;
		}
		else
		{
			return false;
		}
	}
	Plural operator+(const Plural num)                 //加號的過載
	{
		Plural temp;
		temp._real = _real + num._real;
		temp._image = _image + num._image;
		return temp;
	}
	Plural operator-(const Plural num)           // 減號的過載
	{
		Plural temp;
		temp._real = _real - num._real;
		temp._image = _image - num._image;
		return temp;
	}
	Plural operator++(int)                     //後置加加
	{
		return _real++;
	}
	Plural operator--(int)                     //後置減減
	{
		return _real--;
	}
	Plural operator+=(const Plural num)             //加等
	{
		return _real += num._real;
	}
	Plural operator-=(const Plural num)             //減等
	{
		return _real -= num._image;
	}
	Plural operator*(const Plural num)               //乘法
	{
		Plural temp;
		temp._real = _real*num._real - _image*num._image;
		temp._image = _image*num._real + _real*num._image;
		return temp;
	}
	Plural operator/(const Plural num)               //除法
	{
		Plural temp;
		temp._real = ((_real * num._real + _image * num._image) / (num._real * num._real + num._image * num._image));
		temp._image = ((_image * num._real - _real * num._image) / (num._real * num._real + num._image * num._image));
		return temp;
	}
	friend ostream& operator<<(ostream& os, Plural& c);          //輸出運算子的過載
private:
	int _real;
	int _image;
};


ostream& operator<<(ostream& os, Plural& c)
{
	os << c._real << "+" << c._image << "i";
	return os;
}



int main()
{
	Plural p1(3, 4);
	Plural p2(1, 2);
	Plural p3(1, 0);
	Plural p4(1, 0);
	cout << "p1=" << p1 << endl;
	cout << "p2=" << p2 << endl;
	cout << "p3=" << p3 << endl;
	cout << "p4=" << p4 << endl;
	cout << "p1" << "-" << "p2" << "=" <<(p1 - p2) << endl;
	cout << "p1" << "+" << "p2" << "=" << (p1 + p2) << endl;
	cout << "p1" << ">" << "p2" << "=" << (p1 > p2) << endl;
	cout << "p1" << "<" << "p2" << "=" << (p1 > p2) << endl;
	cout << "p1" << "=" << "p2" << "=" << (p1 = p2) << endl;
	cout << "p3" << "=" << "p4" << "=" << (p3 = p4) << endl;
	cout << "p1" << "++" << "=" << (p1++) << endl;
	cout << "p1" << "--" << "=" << (p1++) << endl;
	cout << "p1" << "+=" << "p2" << "=" << (p1+=p2) << endl;
	cout << "p1" << "-=" << "p2" << "=" << (p1-=p2) << endl;

	system("pause");
	return 0;
}