my code c#


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


namespace kyrsach1294
{
    class Program
    {
        static int Main(string[] args)
        { int a,b,c,d;
            string[] dlins = Console.ReadLine().Split(' ');
         a = int.Parse(dlins[0]);
         b = int.Parse(dlins[1]);
         c = int.Parse(dlins[2]);
         d = int.Parse(dlins[3]);
         if (a * b==c * d)
         {
             {
                 Console.WriteLine("Impossible.");
                 return 0;
             }
         }


       double s,s1,s2;
       s1 = c * d / (c * d - a * b);

        s2 = a * b / (c * d - a * b);
       s = s1*a*a+s1*b*b-s2*c*c-s2*d*d;
            if (s < 0)
            {
                Console.WriteLine("Impossible.");
                return 0;
            }
            int answer;

            s = Math.Sqrt(s) * 1000;
            answer = Convert.ToInt32(s);
            Console.WriteLine("Distance is "+answer+" km.");
            return 0;
        }
    }
}
please help

Edited by author 03.04.2012 22:40

Hi, guy.
Don't use Convert.ToInt32 for answer, it's wrong. You should go some other way. For example, first, I used double instead of int, and a small value EPS = 1e-9.
if(Math.Abs(a*b - c*d) < EPS)
{
     Console.WriteLine("Impossible.");
     return;
}

Second, I don't used :
if (s < 0)
{
     Console.WriteLine("Impossible.");
     return 0;
}
It's not necessary. I passed without this.

Third, you should approximate on another way. Convert.ToInt32 don't work correct, but I found the simple trick :
bool flag = false;
x = Math.Sqrt((a*b*(c*c + d*d) - c*d*(a*a + b*b)) / (a*b - c*d));
int y = ((int)(x * 10000.0)) % 10;
if (y >= 5) flag = true;
int ans = (int)(x * 1000.0);
if (flag == true) ++ans;
Console.WriteLine("Distance is {0} km.", ans);

I hope that I helped you. If you will get WA again and again I can send you correct code on your email.

4615234    03:01:21
13 ноя 2012    ZamNick    1294. Марсианские спутники    C#    Accepted
0.109    2 096 КБ