函数有多个返回值

class Program
    {
        /// <summary>
        /// 解一元二次方程
        /// </summary>
        /// <param name="a"></param>
        /// <param name="b"></param>
        /// <param name="c"></param>
        /// <param name="d"></param>
        /// <param name="e"></param>
        /// <returns></returns>
        public int jiefangcheng(int a, int b, int c, out double x1, out double x2)
        {
            x1 = 0;
            x2 = 0;
            if (a == 0)
            {
                return 3;
            }
            else
            {
            int del = b * b - 4 * a * c;


            if (del > 0)
            {
                x1 = (-b + Math.Sqrt(del)) / (2 * a);
                x2 = (-b - Math.Sqrt(del)) / (2 * a);
                return 2;
            }
            else if (del == 0)
            {
                x1 = (-b + Math.Sqrt(del)) / (2 * a);
                x2 = x1;
                return 1;
            }

            else
            {
                return 0;

            }
            }

        }


        static void Main(string[] args)
        {
            //解一元二次方程
            Console.Write("请输入a=");
            int a = int.Parse(Console.ReadLine());
            Console.Write("请输入b=");
            int b = int.Parse(Console.ReadLine());
            Console.Write("请输入c=");
            int c = int.Parse(Console.ReadLine());
            double x1, x2;
            int jieguo = new Program().jiefangcheng(a,b,c,out x1,out x2);
            if(jieguo ==0)
            {
                Console.WriteLine("方程无实根");
            }
            if (jieguo == 1)
            {
                Console.WriteLine("方程有两个相等实根x1=x2="+x1);
            }
            if (jieguo == 2)
            {
                Console.WriteLine("方程有两个相等实根x1=" + x1 + "x2=" + x2);
            }
            if (jieguo == 3)
            {
                Console.WriteLine("不是一元二次方程");
            }
            Console.ReadLine();
        }
    }