函数解一元二次方程

namespace ConsoleApplication10
{
    class Program
    {

        //函数多个返回值、

            //输入参数前加out就变成输出参数

        public int jiefangcheng(int a, int b , int c,out double x1,out double x2)
        {
            x1 = 0;
            x2 = 0;
            if(0== b*b-4*a*c)
            {
                x1 = (-b) / (2 * a);
                x2 = x1;
                return 1;
            }

            else if (0 < b * b - 4 * a * c)
            {
                x1 = (-b + Math.Sqrt(b * b - 4.0 * a * c)) / (2.0 * a);
                x2 = (-b - Math.Sqrt(b * b - 4.0 * a * c)) / (2.0 * a);

                return 2;
            }
               else

            {
                return 0;
            }
        }
        static void Main(string[] args)
        {
            Console.WriteLine("请输入数值a");
            int a = int.Parse(Console.ReadLine());
            Console.WriteLine("请输入数值b");
            int b = int.Parse(Console.ReadLine());
            Console.WriteLine("请输入数值c");
            int c = int.Parse(Console.ReadLine());

            double x1, x2;
            int fanhui = new Program().jiefangcheng(a, b, c, out x1, out x2);

            if(fanhui ==0)
            {

                Console.WriteLine("两个相等的实数根");

                Console.ReadLine();
            }
        }
    }