quadraticequation

namespace Masodfoku
{
    internal class Equation
    {
        private double a, b, c;
        public Equation(double a, double b, double c)
        {
            this.a = a; this.b = b; this.c = c;
        }

        public double FirstDegreeSolution { get; set; }

        public double[] SecondDegreeSolution { get; set; }

        public string ComplexSolution { get; set; }


        //Eldönti, hogy másodfokú-e az egyenlet. Ha igen, true
        //értékkel tér vissza.
        public bool SecondDegree()
        {
            return this.a != 0;
        }

        //Eldönti, hogy az egyenlet megoldása csak komplex szám
        //lehet-e. Ehhez az kell, hogy a diszkrimináns negatív legyen.
        public bool Complex()
        {
            return Math.Pow(this.b, 2) - 4 * this.a * this.c < 0;
        }

        private void EquationHelper()
        {
            if (Complex())
            {
                SolveComplex();
            }
            else if (SecondDegree())
            {
                SolveQuadratic();
            }
            else if(this.a==0)
            {
                SolveSimple();
            }
            throw new ArgumentException();
        }

        private void SolveQuadratic()
        {
            double partOne = -this.b;
            double partTwo = Math.Sqrt(Math.Pow(this.b, 2) - 4 * this.a * this.c);
            double partThree = 2 * this.a;

            this.SecondDegreeSolution = new double[] { (partOne + partTwo) / partThree, (partOne - partTwo) / partThree };
        }

        private void SolveComplex()
        {
            double partOne = -this.b / (2 * this.a);
            double partTwoHelper = Math.Pow(this.b, 2) - 4 * this.a * this.c;
            double rootPartTwo = Math.Sqrt(-partTwoHelper);
            double partTwo = rootPartTwo / (2 * this.a);
            this.ComplexSolution= String.Format("{0}+/-{1}i", partOne, partTwo);
        }

        private void SolveSimple()
        {
            this.FirstDegreeSolution = -this.b / (2 * this.a);
        }
    }
}