Арифметические операции. Комплексные числа

Сomplex q1,w2,e3;

char string[]= "(q1 + w2) * e3";

string[0] = "(";
string[1] = "q1";
string[2] = "+";
и т. д.

#include <iostream>
 
class Complex {
    private:
        double  Re,
                Im;
    public:
        Complex() {Re = 0.0; Im = 0.0;}
        Complex(double Re, double Im = 0.0) {this->Re = Re; this->Im = Im;}
        Complex(const Complex &C) {this->Re = C.Re; this->Im = C.Im;}
        
        ~Complex() {}
        
        Complex operator+(const Complex &C) {Complex R(this->Re + C.Re, this->Im + C.Im); return R;}
        Complex operator-(const Complex &C) {Complex R(this->Re - C.Re, this->Im - C.Im); return R;}
        Complex operator*(const Complex &C) {Complex R(this->Re*C.Re - this->Im*C.Im, this->Re*C.Im + this->Im*C.Re); return R;}
        Complex operator/(const Complex &C) {
            double den = C.Re*C.Re + C.Im*C.Im;
            Complex R((this->Re*C.Re + this->Im*C.Im)/den,(this->Im*C.Re - this->Re*C.Im)/den);
            return R;
        }
 
        friend std::ostream & operator << (std::ostream &cout, const Complex &C) {
            cout << C.Re << (C.Im>0?"+":"");
            if (C.Im!=0) cout << C.Im << "i\n";
            return cout;
        }
        
        void setRe (const double Re) {this->Re = Re; return;}
        void setIm (const double Im) {this->Im = Im; return;}
        
        double getRe() {return this->Re;};
        double getIm() {return this->Im;};
};
 
int main()
{
    Complex A(1.2, 0.7);
    Complex B(A);
    Complex C(A*B);
    std::cout << C;
}