#include "check_dot.h"

const double PI = 3.141592653589793;

int point(std::vector<double>& masx, std::vector<double>& masy, double& x, double& y)

{

double anglesum = 0;

double eps = 1e-7;

for (int i = 0; i < masx.size() - 1; ++i)

{

double x1 = masx[i];

double x2 = masx[i + 1];

double y1 = masy[i];

double y2 = masy[i + 1];

double vax = x1 - x;

double vay = y1 - y;

double vbx = x2 - x;

double vby = y2 - y;

double len_a = std::sqrt(pow(vax, 2) + pow(vay, 2));

double len_b = std::sqrt(pow(vbx, 2) + pow(vby, 2));

double det = (vax * vby - vbx * vay);

double direction = (det >= 0) ? 1 : -1;

if ((len_a < eps) or (len_b < eps))

{

return 0;

}

double norm = (len_a * len_b);

double sk = ((vax * vbx) + (vay * vby));

double cosangle = ((vax * vbx) + (vay * vby)) / (len_a * len_b);

double angle = std::acos(cosangle);

if (fabs(fabs(angle) - PI) < eps)

{

return 1;

}

anglesum = anglesum + angle * direction;

}

if (fabs(fabs(anglesum) - 2 * PI) < eps)

{

return 2;

}

return 3;

}