complex class 구현

Complex Class

C++에서 제공하는 연산자 overloading을 이용해서 복소수를 클래스로 구현해보았다.

복소수 클래스의 멤버 변수들을 외부에서 변경하지 못하게 하기 위해서 private으로 선언하였으며, 멤버 함수는 사칙 연산 및 입출력에 대한 내용에 대해서만 구현을 하였다.

#ifndef COMPLEX_H
#define COMPLEX_H

#include <iostream>

using namespace std;

class Complex{
private:
	double real;
	double imag;
public:
	Complex(double real = 0, double imag = 0) : real(real), imag(imag) {}
	friend Complex operator+(const Complex& c1, const Complex& c2);
	friend Complex operator-(const Complex& c1, const Complex& c2);
	friend Complex operator*(const Complex& c1, const Complex& c2);
	friend Complex operator/(const Complex& c1, const Complex& c2);

	friend bool operator==(const Complex& c1, const Complex& c2);
	friend bool operator!=(const Complex& c1, const Complex& c2);

	friend ostream& operator<< (ostream& out, const Complex& c);
	friend istream& operator>> (istream& in, Complex& c);
};

Complex operator+(const Complex& c1, const Complex& c2){
	return Complex(c1.real + c2.real, c1.imag + c2.imag);
}

Complex operator-(const Complex& c1, const Complex& c2){
	return Complex(c1.real - c2.real, c1.imag - c2.imag);
}

Complex operator*(const Complex& c1, const Complex& c2){
	return Complex(c1.real * c2.real - c1.imag * c2.imag, c1.real * c2.imag + c1.imag * c2.real);
}

Complex operator/(const Complex& c1, const Complex& c2){
	double common = c2.real * c2.real + c2.imag * c2.imag;
	return Complex((c1.real * c2.real + c1.imag * c2.imag)/common, (c1.real * c2.imag - c1.imag * c2.real)/common);
}

bool operator==(const Complex& c1, const Complex& c2){
	return (c1.real == c2.real) && (c1.imag == c2.imag);
}

bool operator!=(const Complex& c1, const Complex& c2){
	return !(c1==c2);
}

ostream& operator<< (ostream& out, const Complex& c){
	out << c.real << " + " << c.imag << "i";
	return out;
}

istream& operator>> (istream& in, Complex& c){
	in >> c.real >> c.imag;
	return in;
}

#endif

만약 멤버 변수들을 public으로 선언하면 아래와 같이 코드를 수정할 수 있다.

#ifndef COMPLEX_H
#define COMPLEX_H

#include <iostream>

using namespace std;

class Complex{
	friend ostream& operator<< (ostream& out, const Complex& c);
	friend istream& operator>> (istream& in, Complex& c);
public:
	Complex(double real = 0, double imag = 0) : real(real), imag(imag) {}
	Complex operator+(const Complex& c);
	Complex operator-(const Complex& c);
	Complex operator*(const Complex& c);
	Complex operator/(const Complex& c);

	bool operator==(const Complex& c);
	bool operator!=(const Complex& c);

	double real;
	double imag;
};

Complex Complex::operator+(const Complex& c){
	return Complex(this->real + c.real, this->imag + c.imag);
}

Complex Complex::operator-(const Complex& c){
	return Complex(this->real - c.real, this->imag - c.imag);
}

Complex Complex::operator*(const Complex& c){
	return Complex(this->real * c.real - this->imag * c.imag, this->real * c.imag + this->imag * c.real);
}

Complex Complex::operator/(const Complex& c){
	double common = c.real * c.real + c.imag * c.imag;
	return Complex((this->real * c.real + this->imag * c.imag)/common, (this->real * c.imag - this->imag * c.real)/common);
}

bool Complex::operator==(const Complex& c){
	return (this->real == c.real) && (this->imag == c.imag);
}

bool Complex::operator!=(const Complex& c){
	return !(*this==c);
}

ostream& operator<< (ostream& out, const Complex& c){
	out << c.real << " + " << c.imag << "i";
	return out;
}

istream& operator>> (istream& in, Complex& c){
	in >> c.real >> c.imag;
	return in;
}

#endif

이것을 complex.h라는 헤더파일로 만들어놓고 필요할 때 불러와서 사용해도 된다.