квадратное уравнение

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
short a=0, b=0, c=0;
double x1=0, x2=0, D=0;

cin >> a >> b >> c;

if (a==0)
{
    if ((b==0) && (c==0))
      cout << -1;
    if ((b==0) && (c!=0))
      cout << 0;
    if (b!=0)
      cout << 1 << " " << -c/b;
}
else
  {
     if ((b==0) && (c==0))
       cout << 1 << " " << 0;
     else
     {
      D = b*b - 4*a*c;
        if (D>=0)
           {
             x1=(-b+sqrt(D))/2/a;
             x2=(-b-sqrt(D))/2/a;
              if (x1==x2)
                cout << 1 << " " << x1;
              else
                {
                  if (x1 < x2)
                   cout << 2 << " " << x1 << " " << x2;
                  else cout << 2 << " " << x2 << " " << x1;
                }
            }
            else cout << 0;
    }
  }
}