/* A complex number can be expressed as (a, b) or as a + bi. a is called the number's real part, and b is called its imaginary part. i is defined by i x i = -1. Write a program that reads complex numbers from the input, multiplies, and prints the result. For example: Input: 1, 2, 3, 4 Output: -5, 10 Explanation: (1+2i) *(3+4i) = 1*3 + 1*4*i + 2*i*3 + 2*i*4*i = 3 + 10*i + 8*i*i = 3 + 10*i + -8 = -5 + 10i Bonus: Implement complex number division. */ #include #include #include //std::numeric_limits() #include //std::isnan() class Complex { double real; double imag; public: Complex(const double& real = 0, const double& imag = 0) :real(real), imag(imag) {} const Complex operator*(const Complex&) const; const Complex operator/(const Complex&) const; const Complex operator/(const double&) const; Complex& operator=(const Complex&); Complex& operator*=(const Complex& z) { return *this = *this * z; } Complex& operator/=(const Complex& z) { return *this = *this / z; } Complex& operator/=(const double& d) { return *this = *this / d; } double getReal() const { return real; } double getImag() const { return imag; } friend std::istream& operator>>(std::istream&, Complex&); friend std::ostream& operator<<(std::ostream&, const Complex&); }; int main() { using namespace std; try { Complex z1; Complex z2; cout << "Input numbers (e.g. 3 5.2 4.5 2):" << endl; cin >> z1 >> z2; cout << "Numbers are: " << z1.getReal() << " " << z1.getImag() << " " << z2.getReal() << " " << z2.getImag(); cout << endl << endl; cout << "z1 = " << z1 << endl; cout << "z2 = " << z2 << endl; cout << endl; cout << "z1 * z2 = " << z1 * z2 << endl; cout << "z1 / z2 = " << z1 / z2 << endl; } catch(exception ex) { cout << ex.what() << endl; } return 0; } const Complex Complex::operator*(const Complex& z) const { Complex tmp(*this); tmp.real = real * z.real - imag * z.imag; tmp.imag = real * z.imag + z.real * imag; return tmp; } const Complex Complex::operator/(const Complex& z) const { Complex numerator = *this * Complex(z.real, z.imag * (-1)); Complex denominator = z * Complex(z.real, z.imag * (-1)); //denominator hasn't imaginary part, so denominator == denominator.real //and therefore we can use operator/(const double&) return numerator / denominator.real; } const Complex Complex::operator/(const double& d) const { return Complex(real / d, imag / d); } Complex& Complex::operator=(const Complex& z) { real = z.real; imag = z.imag; return *this; } std::istream& operator>>(std::istream& in, Complex& z) { in >> z.real >> z.imag; return in; } std::ostream& operator<<(std::ostream& out, const Complex& z) { //in case of infinity or not a number just out real part //to avoid infinf or nannan values or smth like that if(z.real == std::numeric_limits::infinity() || std::isnan(z.real)) { out << z.real; } else { const char *sign = (z.imag >= 0) ? "+" : ""; out << z.real << sign << z.imag << "i"; } return out; }

[Assignment] Complex Number Multiplication