#include <iostream>
#include <math.h>

using namespace std;

int main()
{
    cout << "This program solves quadratic equations." << endl;

    double a, b, c, d, x1, x2;        //Initializes variables
    double e;        //This is for the complex calculation

    cout <<"a: ";   //Asks for variables
    cin >> a;
    cin.ignore();
    cout <<"b: ";
    cin >> b;
    cin.ignore();
    cout <<"c: ";
    cin >> c;
    cin.ignore();

    d = pow(b,2) - 4*a*c;    //Calculates what is under the square root
    e = sqrt(fabs(d));       //For complex calculation

    if (d < 0)
        if (b > 0)
            {cout << "The equation has two complex solutions." << endl;
            cout << "X1 = " << b/(2*a) <<" + " << e/(2*a) << "i" << endl;
            cout << "X1 = " << b/(2*a) <<" - " << e/(2*a) << "i" << endl;
            cin.get();
            return(0);}
        else
            {cout << "The equation has two complex solutions." << endl;
            cout << "X1 =  " << e/(2*a) << "i" << endl;
            cout << "X1 = " << -e/(2*a) << "i" << endl;
            cin.get();
            return(0);}
    else if (a == 0)
        {cout<< "That is not a quadratic equation." << endl;
        cin.get();
        return(0);}
    else if (d == 0)
        {cout<<"The equation has one solution." << endl;
        x1 = ((-b)+sqrt(d))/(2*a);
        cout<<"X: " << x1 << endl;
        cin.get();
        return(0);}
    else
        {cout<<"The equation has two solutions." << endl;
        x1 = ((-b)+sqrt(d))/(2*a);
        x2 = ((-b)-sqrt(d))/(2*a);
        cout<<"X1: " << x1 << endl;
        cout<<"X2: " << x2 << endl;
        cin.get();
        return(0);}
}