/* randomly shuffle edges */
static void shuffle(rng_t* rng, edge_t* edges, unsigned long n)
{
unsigned long i, j;
edge_t e;
for (i = n - 1; i > 0; --i) {
j = rng_uniform_int(rng, i + 1);
// swap
edgecpy(&e, &edges[j]);
edgecpy(&edges[j], &edges[i]);
edgecpy(&edges[i], &e);
}
}
static void push_edge(edge_array_t* E, const edge_t* e)
{
if (E->m >= E->size) {
E->size *= 2;
E->es = realloc_or_die(E->es, E->size * sizeof(edge_t));
}
edgecpy(&E->es[E->m++], e);
}
void reduce_group_vertices(int g)
{
int *rtab;
int g_size;
Bool changed=False;
g_size=group_size(g,group, vertex_used);
if(g_size==0)
{
printf("current group contains 0 vertices !!!\n");
return;
}
rtab= (int*) malloc(2*g_size*sizeof(int));
{
int i,j;
j=0;
for(i=0; i<VERTEX_MAX && j<g_size; i++)
if(vertex_used[i] && group[i]==g)
{
*(rtab+2*j)=i;
*(rtab+2*j+1)=j;
j++;
}
for(i=1; i<g_size; i++)
for(j=0; j<i && *(rtab+2*i+1)== i; j++)
if(vector_distance(vertex[*(rtab+2*i)],vertex[*(rtab+2*j)])<=
reduction_epsilon)
{
changed=True;
while(*(rtab+2*j+1)!=j) j=*(rtab+2*j+1);
*(rtab+2*i+1)=j;
}
}
if(!changed)
{
printf("No vertex reductions can be done.\n");
free(rtab);
return;
}
group_statistics(g);
backup();
printf("REDUCING ...\n");
{
int i, old_top, e[3], t[4];
graph_marked_init();
for(i=0; i<g_size; i++)
graph_marked[*(rtab+2*i)]= *(rtab+2*(*(rtab+2*i+1)));
/* if graph_marked[i]!=-1 thten group[i]== g and i should be replaced */
/* by graph_marked[i] */
/* REDUCE EDGES */
old_top=edge_top;
i=0;
while(i<edge_top)
if(graph_marked[edge[i][0]]!= -1||
graph_marked[edge[i][1]]!= -1
)
{
edgecpy(e, edge[i]);
edge_delete(i);
e[0]=graph_marked[e[0]];
e[1]=graph_marked[e[1]];
edge_sort(e);
edgecpy(edge[edge_top],e);
}
else i++;
qsort(edge+edge_top, old_top-edge_top, sizeof(int[3]), edge_compare);
i=edge_top;
while(i<old_top)
{
if(i==0 || !edge_eq(edge[i-1],edge[i]))
{
edgecpy(edge[edge_top],edge[i]);
vertex_used[edge[edge_top][0]]++;
vertex_used[edge[edge_top][1]]++;
edge_top++;
}
i++;
}
/* REDUCE TRIANGLES */
old_top=triangle_top;
i=0;
while(i<triangle_top)
if(graph_marked[triangle[i][0]]!= -1||
graph_marked[triangle[i][1]]!= -1||
graph_marked[triangle[i][2]]!= -1
)
{
trianglecpy(t, triangle[i]);
triangle_delete(i);
t[0]=graph_marked[t[0]];
t[1]=graph_marked[t[1]];
t[2]=graph_marked[t[2]];
triangle_sort(t);
trianglecpy(triangle[triangle_top],t);
}
else i++;
qsort(triangle+triangle_top, old_top-triangle_top, sizeof(int[4]),
triangle_compare);
i=triangle_top;
while(i<old_top)
{
if(i==0 || !triangle_eq(triangle[i-1],triangle[i]))
{
trianglecpy(triangle[triangle_top],triangle[i]);
vertex_used[triangle[triangle_top][0]]++;
vertex_used[triangle[triangle_top][1]]++;
vertex_used[triangle[triangle_top][2]]++;
triangle_top++;
}
i++;
}
/* DOKONCZ ... dla triangles */
}
free(rtab);
group_statistics(g);
}
