1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5  6 namespace ConsoleApplication1 7 { 8     class Program 9     {10         static void Main(string[] args)11         {12             //输入13             Console.Write("分别输入a,b,c三个数");14             string a1 = Console.ReadLine();15             string b1 = Console.ReadLine();16             string c1 = Console.ReadLine();17             int a = Convert.ToInt32(a1);18             int b = Convert.ToInt32(b1);19             int c = Convert.ToInt32(c1);20 21             if (a == 0)22             {23                 Console.WriteLine("不是一元二次方程");24             }25             else26             {27                 int d = b * b - 4 * a * c;28                 if (d < 0)29                 {30                     Console.WriteLine("一元二次方程无实根");31                 }32                 else if (d == 0)33                 {34                     Console.WriteLine("一元二次方程有两个相同实根");35                 }36                 else37                 {38                     Console.WriteLine("一元二次方程有两个不同实");39                 }40             }41 42         }43     }44 }