复数的完整C++实现

复数的完整C++实现

// Author:  Keith A. Shomper
// Date:    11/17/03
// Purpose: To demonstrate a class
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
using std::ostream;
using std::istream;

class complex_number {
    public:
        complex_number(double real = 0.0, double imag = 0.0):r(real),i(imag) {}
        complex_number(const complex_number& rhs):r(rhs.r),i(rhs.i){};
        complex_number operator=(const complex_number& rhs){
            if(this!=&rhs){
                r=rhs.r;
                i=rhs.i;
            }
            return *this;
        }
        complex_number& operator+=(const complex_number& rhs);
        complex_number& operator-=(const complex_number& rhs);
        complex_number& operator*=(const complex_number& rhs);
        complex_number& operator/=(const complex_number& rhs);

        friend complex_number operator+ (const complex_number &a, const complex_number &b);
        friend complex_number operator- (const complex_number &a, const complex_number &b);
        friend complex_number operator* (const complex_number &a, const complex_number &b);
        friend complex_number operator/ (const complex_number &a, const complex_number &b);

        friend ostream& operator<<(ostream& os, const complex_number& rhs);
    private:
        double r;
        double i;
};
complex_number& complex_number::operator+=(const complex_number& rhs){
    r+=rhs.r;
    i+=rhs.i;
    return *this;
}
complex_number& complex_number::operator-=(const complex_number& rhs){
    r-=rhs.r;
    i-=rhs.i;
    return *this;
}
complex_number& complex_number::operator*=(const complex_number& rhs){
    r = (r * rhs.r - i * rhs.i);
    i = (r * rhs.i + i * rhs.r);
    return *this;
}
complex_number& complex_number::operator/=(const complex_number& rhs){
    r = (r * rhs.r + i * rhs.i) / (rhs.r * rhs.r + rhs.i * rhs.i);
    i = (i * rhs.r - r * rhs.i) / (rhs.r * rhs.r + rhs.i * rhs.i);
    return *this;
}

complex_number operator+ (const complex_number &a, const complex_number &b) {
    complex_number result(a);
    result+=b;

    return result;
}
complex_number operator- (const complex_number &a, const complex_number &b) {
    complex_number result(a);
    result-=b;

    return result;
}

complex_number operator* (const complex_number &a, const complex_number &b) {
    complex_number result(a);
    result*=b;

    return result;
}

complex_number operator/ (const complex_number &a, const complex_number &b) {
    complex_number result(a);
    result/=b;
    return result;
}

ostream& operator<<(ostream& os,const complex_number& rhs){
    os<<rhs.r<<"+"<<rhs.i<<"i";
}

int main () {
    complex_number x(1, 2), y, z;
    complex_number sum, difference, product, quotient;

    y = complex_number(2, 4);

    z = complex_number(3, 0);

    cout << "x is:  "<< x<< endl;
    cout << "y is:  "<< y<< endl;
    cout << "z is:  "<< z<< endl;

    sum        = x + y;
    difference = x - y;
    product    = x * y;
    quotient   = sum / z;
    cout << "The sum (x + y) is:  "<<sum << endl;
    cout << "The difference (x - y) is:  "<<difference<< endl;
    cout << "The product (x * y) is:  "<<product << endl;
    cout << "The quotient (sum / z) is:  "<<quotient << endl;
    complex_number a=5;
    cout<<"a="<<a<<endl;
    a+=3;
    cout<<"a="<<a<<endl;

    return 0;
}