#include <vector>
#include <iostream>

#ifdef _MSC_VER
#include <cfloat>
#else
#include <cmath>
#endif

void buggy_function(double eps = 1e-13, int length = 3, double delta = 1 / 7.0)
{
  using namespace std;
  double alpha = 1e-13;
  double beta = eps;
  double a = length * delta;
  double b = length * delta;
  vector<double> inverse;
  for (int i = 0; i < length; ++i)
    inverse.push_back(1.0/(2*i+1));
  vector<double> sorted;
  for (int i = 0; i < length; ++i)
    sorted.push_back(inverse[i]*delta);

  double t = -delta*sorted.size();
  double tt = -sorted.size()*delta;
  bool t_tt = (abs(t-tt) < eps);
  bool abs_t = (abs(t) == -t);
  double c = (1-alpha) * a + alpha * b;
  double d = (1-beta) * a + beta * b;
  bool a_c = (a == c);
  bool b_d = (b == d);
  vector<bool> equal;
  for (int i = 0; i < length; ++i)
    equal.push_back(inverse[i]*delta == sorted[i]);

  std::cout << "t_tt  = " << t_tt << "\nabs_t = "  << abs_t << "\na_c   = " << a_c << "\nb_d   = " << b_d << "\n";
  std::cout << "equal = [";
  for (int i = 0; i < length; ++i)
    std::cout << " " << equal[i];
  std::cout << " ]\n";
}

int main ()
{
  buggy_function();
#ifdef _MCW_PC
  _controlfp(_PC_64, _MCW_PC);
  std::cout << "set floating point unit to 'high' precision:\n";
  buggy_function();
#endif
  return 0;
}