using System;

public class QuadraticEq{

    private int a, b, c;

    private int discriminant;

    public int Discriminant{

        get{return discriminant;}

    }

    public QuadraticEq(int ax, int bx, int cx){

        a=ax;

        b=bx;

        c=cx;

        discriminant=b*b-4*a*c;

    }

    public double[] GetRealRoots(){

        double[] soln;

        double dis,ad,bd;

        dis=discriminant;

        ad=a;

        bd=b;

        if(discriminant<0){

            soln=new double[0];

            //soln=null;

        }else if(discriminant==0){

            soln= new double[1];

            soln[0]=(Math.Sqrt(dis)-bd)/2.0/ad;

        }else{

            soln=new double[2];

            /*double x=(Math.Sqrt(dis)-bd)/2.0/ad;

            Console.WriteLine("{0}",x);*/

            soln[0]=(Math.Sqrt(dis)-bd)/2.0/ad;

            soln[1]=(-Math.Sqrt(dis)-bd)/2.0/ad;

        }

        return soln;

    }

}

​

public class Program

{

    public static void Main()

    {

        QuadraticEq q = new QuadraticEq(1,4,1);

        Console.WriteLine("d = {0}", q.Discriminant);

        double[] results = q.GetRealRoots();        

        foreach (double x in results)

        Console.WriteLine(x);

​

    }

}