Simple C# Code for finding roots of Quadratic Equation

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;


namespace Postslush
{
    class Quadratic
    {
        double a, b, c;

        public void read()
        {
            Console.WriteLine(" \n To find the roots of a quadratic equation of the form a*x*x + b*x + c = 0");
            Console.Write("\n Enter value for a : ");
            a = double.Parse(Console.ReadLine());
            Console.Write("\n Enter value for b : ");
            b = double.Parse(Console.ReadLine());
            Console.Write("\n Enter value for c : ");
            c = double.Parse(Console.ReadLine());
        }
        public void compute()
        {
            int m;
            double r1, r2, disc;
            disc = b * b - 4 * a * c;
            if (a == 0)
                m = 1;
            else if (disc > 0)
                m = 2;
            else if (disc == 0)
                m = 3;
            else
                m = 4;
            switch (m)
            {
                case 1: Console.WriteLine("\n Not a Quadratic equation, Linear equation !!!");
                    Console.ReadLine();
                    break;
                case 2: Console.WriteLine("\n Roots are Real and Distinct");
                    r1 = (-b + Math.Sqrt(disc)) / (2 * a);
                    r2 = (-b - Math.Sqrt(disc)) / (2 * a);
                    Console.WriteLine("\n First root is {0:#.##}", r1);
                    Console.WriteLine("\n Second root is {0:#.##}", r2);
                    Console.ReadLine();
                    break;
                case 3: Console.WriteLine("\n Roots are Real and Equal");
                    r1 = r2 = (-b) / (2 * a);
                    Console.WriteLine("\n First root is {0:#.##}", r1);
                    Console.WriteLine("\n Second root is {0:#.##}", r2);
                    Console.ReadLine();
                    break;
                case 4: Console.WriteLine("\n Roots are Imaginary");
                    r1 = (-b) / (2 * a);
                    r2 = Math.Sqrt(-disc) / (2 * a);
                    Console.WriteLine("\n First root is {0:#.##} + i {1:#.##}", r1, r2);
                    Console.WriteLine("\n Second root is {0:#.##} - i {1:#.##}", r1, r2);
                    Console.ReadLine();
                    break;
            }
        }
    }

    class Roots
    {
        public static void Main()
        {
            Quadratic qd = new Quadratic();
            qd.read();
            qd.compute();
        }
    }
}