void init(VD & t, int & n, PDD * p, PDD & a, PDD & b) {
t.clear();
double tmp;
for (int i = 0; i < n; ++i) {
scanf("%lf", &tmp);
t.PB(tmp);
}
std::sort(t.begin(), t.end());
t.erase(std::unique(t.begin(), t.end()), t.end());
n = t.size();
for (int i = 0; i < n; ++i) {
p[i] = at(a, b, t[i]);
}
}
vector <double> collision(int vx, int vy, int vz, int x0, int y0, int z0) {
VD result;
if (vx == 0 and vy == 0) {
if (vz == 0) {
double x1 = cos(PI*z0);
double y1 = sin(PI*z0);
DBG2("x1",x1);
DBG2("y1",y1);
bool ok_x = fabs(x1-x0) < EPS;
bool ok_y = fabs(y1-y0) < EPS;
DBG2("ok_x",ok_x);
DBG2("ok_y",ok_y);
if (ok_x and ok_y) {
result.PB(x0); result.PB(y0); result.PB(z0);
}
}
else {
if (x0*x0+y0*y0 == 1) {
result.PB(0); result.PB(0); result.PB(0);
}
}
return result;
}
double a = vx*vx+vy*vy;
double b = vx*x0+vy*y0;
double c = x0*x0+y0*y0-1;
double D = b*b-a*c;
DBG2("a",a);
DBG2("b",b);
DBG2("c",c);
DBG2("D",D);
if (D<0) return result;
//double t1 = (-b-sqrt(D))/a;
//double t2 = (-b+sqrt(D))/a;
//DBG2("t1",t1);
//DBG2("t2",t2);
double x1 = vx*(-b-sqrt(D))/a+x0;
double y1 = vy*(-b-sqrt(D))/a+y0;
double z1 = vz*(-b-sqrt(D))/a+z0;
double x2 = vx*(-b+sqrt(D))/a+x0;
double y2 = vy*(-b+sqrt(D))/a+y0;
double z2 = vz*(-b+sqrt(D))/a+z0;
DBG2("x1",x1);
DBG2("y1",y1);
DBG2("z1",z1);
DBG2("x2",x2);
DBG2("y2",y2);
DBG2("z2",z2);
double th1 = atan2(y1, x1);
double th2 = atan2(y2, x2);
DBG2("th1",th1);
DBG2("th2",th2);
double z1_c = th1/PI;
double z2_c = th2/PI;
DBG2("z1_c",z1_c);
DBG2("z2_c",z2_c);
double diff_z1 = z1 - z1_c;
double diff_z2 = z2 - z2_c;
DBG2("diff_z1",diff_z1);
DBG2("diff_z2",diff_z2);
bool ok1 = fmod(fabs(diff_z1),2) < EPS;
bool ok2 = fmod(fabs(diff_z2),2) < EPS;
DBG2("ok1",ok1);
DBG2("ok2",ok2);
if (ok1 and ok2 and D!=0) {
result.PB(0); result.PB(0); result.PB(0);
}
else if (ok1) {
result.PB(x1); result.PB(y1); result.PB(z1);
}
else if (ok2) {
result.PB(x2); result.PB(y2); result.PB(z2);
}
return result;
}