/* Merge the nodes of a min, max, or same rank set. */
void collapse_rankset(graph_t *g, graph_t *subg, int kind)
{
node_t *u,*v;
u = v = agfstnode(subg);
if (u) {
ND_ranktype(u) = kind;
while ((v = agnxtnode(subg,v))) {
UF_union(u,v);
ND_ranktype(v) = ND_ranktype(u);
}
switch (kind) {
case MINRANK: case SOURCERANK:
if (GD_minset(g) == NULL) GD_minset(g) = u;
else GD_minset(g) = UF_union(GD_minset(g),u);
break;
case MAXRANK: case SINKRANK:
if (GD_maxset(g) == NULL) GD_maxset(g) = u;
else GD_maxset(g) = UF_union(GD_maxset(g),u);
break;
}
switch (kind) {
case SOURCERANK: GD_minset(g)->u.ranktype = kind; break;
case SINKRANK: GD_maxset(g)->u.ranktype = kind; break;
}
}
}
static void
cluster_leader(graph_t * clust)
{
node_t *leader, *n;
int maxrank = 0;
/* find number of ranks and select a leader */
leader = NULL;
for (n = GD_nlist(clust); n; n = ND_next(n)) {
if ((ND_rank(n) == 0) && (ND_node_type(n) == NORMAL))
leader = n;
if (maxrank < ND_rank(n))
maxrank = ND_rank(n);
}
assert(leader != NULL);
GD_leader(clust) = leader;
for (n = agfstnode(clust); n; n = agnxtnode(clust, n)) {
assert((ND_UF_size(n) <= 1) || (n == leader));
UF_union(n, leader);
ND_ranktype(n) = CLUSTER;
}
}
