/*
*Copyright(c) 2016.煙臺大學計算機與控制工程學院
*ALL rights  reserved.
*檔名稱：main.cpp
*作者：王璵璠
*完成日期：2016年6月16日

 問題描述：

請用類的友元函式，定義複數類過載運算子+、-、*、/，使之能用於複數的加減乘

程式：

#include<iostream>
using namespace std;
class Complex
{
public:
    Complex(){real=0;imag=0;}
    Complex(double r,double i){real=r; imag=i;}
    friend Complex operator+(Complex &c1,Complex &c2);
    friend Complex operator-(Complex &c1,Complex &c2);
    friend Complex operator*(Complex &c1,Complex &c2);
    friend Complex operator/(Complex &c1,Complex &c2);
    void display();
private:
    double real;
    double imag;
};
//下面定義成員函式
//複數相加： (a+bi)+(c+di)=(a+c)+(b+d)i
Complex operator+(Complex &c1,Complex &c2)
{
    Complex c;
    c.real=c1.real+c2.real;
    c.imag=c1.imag+c2.imag;
    return c;
}
//複數相減： (a+bi)-(c+di)=(a-c)+(b-d)i
Complex operator-(Complex &c1,Complex &c2)
{
    Complex c;
    c.real=c1.real-c2.real;
    c.imag=c1.imag-c2.imag;
    return c;
}
//複數相乘：(a+bi)(c+di)=(ac－bd)+(bc+ad)i
Complex operator*(Complex &c1,Complex &c2)
{
    Complex c;
    c.real=c1.real*c2.real-c1.imag*c2.imag;
    c.imag=c1.imag*c2.real+c1.real*c2.imag;
    return c;
}

//複數相除：(a+bi)/(c+di)=(ac+bd)/(c*c+d*d) +(bc-ad)/(c*c+d*d)i
Complex operator/(Complex &c1,Complex &c2)
{
    Complex c;
    c.real=(c1.real*c2.real+c1.imag*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
    c.imag=(c1.imag*c2.real-c1.real*c2.imag)/(c2.real*c2.real+c2.imag*c2.imag);
    return c;
}
 void Complex::display()
{
    cout<<"("<<real<<","<<imag<<"i)"<<endl;
}
//下面定義用於測試的main()函式
int main()
{
    Complex c1(3,4),c2(5,-10),c3;
    cout<<"c1=";
    c1.display();
    cout<<"c2=";
    c2.display();
    c3=c1+c2;
    cout<<"c1+c2=";
    c3.display();
    c3=c1-c2;
    cout<<"c1-c2=";
    c3.display();
    c3=c1*c2;
    cout<<"c1*c2=";
    c3.display();
    c3=c1/c2;
    cout<<"c1/c2=";
    c3.display();
    return 0;
}
 

執行結果：