Agedge_t *agfstin(Agraph_t * g, Agnode_t * n)
{
Agsubnode_t *sn;
Agedge_t *e = NILedge;
sn = agsubrep(g, n);
dtrestore(g->e_seq, sn->in_seq);
e = (Agedge_t *) dtfirst(g->e_seq);
sn->in_seq = dtextract(g->e_seq);
return e;
}
int agdegree(Agraph_t * g, Agnode_t * n, int want_in, int want_out)
{
Agsubnode_t *sn;
int rv = 0;
sn = agsubrep(g, n);
if (sn) {
if (want_out) rv += cnt(g->e_seq,&(sn->out_seq));
if (want_in) rv += cnt(g->e_seq,&(sn->in_seq));
}
return rv;
}
/* return first outedge of <n> */
Agedge_t *agfstout(Agraph_t * g, Agnode_t * n)
{
Agsubnode_t *sn;
Agedge_t *e = NILedge;
sn = agsubrep(g, n);
if (sn) {
dtrestore(g->e_seq, sn->out_seq);
e = (Agedge_t *) dtfirst(g->e_seq);
sn->out_seq = dtextract(g->e_seq);
}
return e;
}
Agedge_t *agnxtin(Agraph_t * g, Agedge_t * e)
{
Agnode_t *n;
Agsubnode_t *sn;
Agedge_t *f;
n = AGHEAD(e);
sn = agsubrep(g, n);
dtrestore(g->e_seq, sn->in_seq);
f = (Agedge_t *) dtnext(g->e_seq, e);
sn->in_seq = dtextract(g->e_seq);
return f;
}
/* return outedge that follows <e> of <n> */
Agedge_t *agnxtout(Agraph_t * g, Agedge_t * e)
{
Agnode_t *n;
Agsubnode_t *sn;
Agedge_t *f = NILedge;
n = AGTAIL(e);
sn = agsubrep(g, n);
if (sn) {
dtrestore(g->e_seq, sn->out_seq);
f = (Agedge_t *) dtnext(g->e_seq, e);
sn->out_seq = dtextract(g->e_seq);
}
return f;
}
int agcountuniqedges(Agraph_t * g, Agnode_t * n, int want_in, int want_out)
{
Agedge_t *e;
Agsubnode_t *sn;
int rv = 0;
sn = agsubrep(g, n);
if (want_out) rv = cnt(g->e_seq,&(sn->out_seq));
if (want_in) {
if (!want_out) rv += cnt(g->e_seq,&(sn->in_seq)); /* cheap */
else { /* less cheap */
for (e = agfstin(g, n); e; e = agnxtin(g, e))
if (e->node != n) rv++; /* don't double count loops */
}
}
return rv;
}
