circle spanning_circle(vector<point>& T)
{
int n = T.size();
random_shuffle(ALL(T));
circle C(point(), -INFINITY);
for (int i = 0; i < n; i++) if (!in_circle(C, T[i]))
{
C = circle(T[i], 0);
for (int j = 0; j < i; j++) if (!in_circle(C, T[j]))
{
C = circle((T[i] + T[j]) / 2, abs(T[i] - T[j]) / 2);
for (int k = 0; k < j; k++) if (!in_circle(C, T[k]))
{
point o = circumcenter(T[i], T[j], T[k]);
C = circle(o, abs(o - T[k]));
}
}
}
return C;
}
circle minimum_circle(vector<point> p) {
circle ret;
random_shuffle(p.begin(), p.end());
for (int i = 0; i < (int)p.size(); ++i)
if (!in_circle(p[i], ret)) {
ret = circle(p[i], 0);
for (int j = 0; j < i; ++j)
if (!in_circle(p[j], ret)) {
ret = make_circle(p[j], p[i]);
for (int k = 0; k < j; ++k)
if (!in_circle(p[k], ret))
ret = make_circle(p[i], p[j], p[k]);
}
}
return ret;
}
double serial_execution(){
int circle=0;
for(int i=1;i<=ITERS;i++){
int x = safe_rand()%100;
int y = safe_rand()%100;
circle += in_circle(x,y);
}
return circle/(double)ITERS;
}
/*
* validate a link
*/
static halfedge_t* del_valid_link( halfedge_t *b )
{
point2d_t *g, *g_p, *d, *d_p;
halfedge_t *gd, *dd, *new_gd, *new_dd;
int a;
g = b->vertex;
gd = del_valid_left(b);
g_p = gd->vertex;
d = b->alpha->vertex;
dd = del_valid_right(b);
d_p = dd->vertex;
if( g != g_p && d != d_p )
{
a = in_circle(g, d, g_p, d_p);
if( a != ON_CIRCLE )
{
if( a == INSIDE )
{
g_p = g;
gd = b;
}
else
{
d_p = d;
dd = b->alpha;
}
}
}
/* create the 2 halfedges */
new_gd = halfedge_alloc();
new_dd = halfedge_alloc();
/* setup new_gd and new_dd */
new_gd->vertex = gd->vertex;
new_gd->alpha = new_dd;
new_gd->amgis = gd;
new_gd->sigma = gd->sigma;
gd->sigma->amgis = new_gd;
gd->sigma = new_gd;
new_dd->vertex = dd->vertex;
new_dd->alpha = new_gd;
new_dd->amgis = dd->amgis;
dd->amgis->sigma = new_dd;
new_dd->sigma = dd;
dd->amgis = new_dd;
return new_gd;
}
/*
* pass through all the halfedges on the left side and validate them
*/
static halfedge_t* del_valid_left( halfedge_t* b )
{
point2d_t *g, *d, *u, *v;
halfedge_t *c, *du, *dg;
g = b->vertex; /* base halfedge point */
dg = b;
d = b->alpha->vertex; /* alpha(halfedge) point */
b = b->sigma;
u = b->alpha->vertex; /* sigma(alpha(halfedge)) point */
du = b->alpha;
v = b->sigma->alpha->vertex; /* alpha(sigma(sigma(halfedge)) point */
if( classify_point_seg(g, d, u) == ON_LEFT )
{
/* 3 points aren't colinear */
/* as long as the 4 points belong to the same circle, do the cleaning */
while( v != d && in_circle(g, d, u, v) == INSIDE )
{
c = b->sigma;
du = b->sigma->alpha;
del_remove_halfedge(b);
b = c;
u = du->vertex;
v = b->sigma->alpha->vertex;
}
if( v != d && in_circle(g, d, u, v) == ON_CIRCLE )
{
du = du->amgis;
del_remove_halfedge(b);
}
} else /* treat the case where the 3 points are colinear */
du = dg;
return du;
}
/*
* Function goes through a number of darts, each time randomly gets a pair of x,y coords that
* are inside a 1x1 square. Checks if point is in circle, if so increments cnt.
*/
int throw_darts(unsigned int darts) {
double x, y;
int cnt = 0;
for (unsigned int i = 0; i < darts; ++i) {
x = rand() / (float)RAND_MAX;
y = rand() / (float)RAND_MAX;
if (in_circle(x, y, RADIUS))
cnt++;
}
return cnt;
}
/*
* pass through all the halfedges on the right side and validate them
*/
static halfedge_t* del_valid_right( halfedge_t *b )
{
point2d_t *g, *d, *u, *v;
halfedge_t *c, *dd, *du;
b = b->alpha;
d = b->vertex;
dd = b;
g = b->alpha->vertex;
b = b->amgis;
u = b->alpha->vertex;
du = b->alpha;
v = b->amgis->alpha->vertex;
if( classify_point_seg(g, d, u) == ON_LEFT )
{
while( v != g && in_circle(g, d, u, v) == INSIDE )
{
c = b->amgis;
du = c->alpha;
del_remove_halfedge(b);
b = c;
u = du->vertex;
v = b->amgis->alpha->vertex;
}
if( v != g && in_circle(g, d, u, v) == ON_CIRCLE )
{
du = du->sigma;
del_remove_halfedge(b);
}
} else
du = dd;
return du;
}
double parallel_execution(int t){
int circle=0;
int i,x,y;
omp_set_num_threads(t);
double start_time = omp_get_wtime();
#pragma omp parallel private(x,y) reduction(+:circle)
{
#pragma parallel for
for(i=1;i<=ITERS;i++){
x = safe_rand()%100;
y = safe_rand()%100;
circle += in_circle(x,y);
}
}
printf("Threads: %d, Value: %lf, Time: %lf\n",t,circle/(double)ITERS*4, omp_get_wtime() - start_time);
}
