/* clone_graph:
* Create two copies of the argument graph
* One is a subgraph, the other is an actual copy since we will be
* adding edges to it.
*/
static Agraph_t*
clone_graph(Agraph_t* ing, Agraph_t** xg)
{
Agraph_t* clone;
Agraph_t* xclone;
Agnode_t* n;
Agnode_t* xn;
Agnode_t* xh;
Agedge_t* e;
Agedge_t* xe;
char gname[SMALLBUF];
static int id = 0;
sprintf (gname, "_clone_%d", id++);
clone = agsubg(ing, gname);
sprintf (gname, "_clone_%d", id++);
xclone = agopen(gname, ing->kind);
for(n = agfstnode(ing); n; n = agnxtnode(ing, n)) {
aginsert (clone, n);
xn = agnode (xclone, n->name);
CLONE(n) = xn;
}
for(n = agfstnode(ing); n; n = agnxtnode(ing, n)) {
xn = CLONE(n);
for(e = agfstout(ing, n); e; e = agnxtout(ing, e)) {
aginsert (clone, e);
xh = CLONE(e->head);
xe = agedge (xclone, xn, xh);
ORIGE(xe) = e;
DEGREE(xn) += 1;
DEGREE(xh) += 1;
}
}
*xg = xclone;
#ifdef OLD
clone = agopen("clone", root->kind);
for(n = agfstnode(root); n; n = agnxtnode(root, n)) {
cn = agnode(clone, n->name);
ND_alg(cn) = DATA(n);
BCDONE(cn) = 0;
}
for(n = agfstnode(root); n; n = agnxtnode(root, n)) {
Agnode_t *t = agnode(clone, n);
for(e = agfstout(root, n); e; e = agnxtout(root, e)) {
Agnode_t *h = agnode(clone, e->head->name);
agedge(clone, t, h);
}
}
#endif
return clone;
}
/* find_pair_edges:
*/
static void find_pair_edges(Agraph_t * g, Agnode_t * n, Agraph_t * outg)
{
Agnode_t **neighbors_with;
Agnode_t **neighbors_without;
Agedge_t *e;
Agedge_t *ep;
Agedge_t *ex;
Agnode_t *n1;
Agnode_t *n2;
int has_pair_edge;
int diff;
int has_pair_count = 0;
int no_pair_count = 0;
int node_degree;
int edge_cnt = 0;
node_degree = DEGREE(n);
neighbors_with = N_GNEW(node_degree, Agnode_t *);
neighbors_without = N_GNEW(node_degree, Agnode_t *);
for (e = agfstedge(g, n); e; e = agnxtedge(g, e, n)) {
n1 = e->head;
if (n1 == n)
n1 = e->tail;
has_pair_edge = 0;
for (ep = agfstedge(g, n); ep; ep = agnxtedge(g, ep, n)) {
if (ep == e)
continue;
n2 = ep->head;
if (n2 == n)
n2 = ep->tail;
ex = agfindedge(g, n1, n2);
if (ex) {
has_pair_edge = 1;
if (n1 < n2) { /* count edge only once */
edge_cnt++;
if (ORIGE(ex)) {
agdelete(outg, ORIGE(ex));
ORIGE(ex) = 0; /* delete only once */
}
}
}
}
if (has_pair_edge) {
neighbors_with[has_pair_count] = n1;
has_pair_count++;
} else {
neighbors_without[no_pair_count] = n1;
no_pair_count++;
}
}
diff = node_degree - 1 - edge_cnt;
if (diff > 0) {
int mark;
Agnode_t *hp;
Agnode_t *tp;
if (diff < no_pair_count) {
for (mark = 0; mark < no_pair_count; mark += 2) {
if ((mark + 1) >= no_pair_count)
break;
tp = neighbors_without[mark];
hp = neighbors_without[mark + 1];
agedge(g, tp, hp);
DEGREE(tp)++;
DEGREE(hp)++;
diff--;
}
mark = 2;
while (diff > 0) {
tp = neighbors_without[0];
hp = neighbors_without[mark];
agedge(g, tp, hp);
DEGREE(tp)++;
DEGREE(hp)++;
mark++;
diff--;
}
}
else if (diff == no_pair_count) {
tp = neighbors_with[0];
for (mark = 0; mark < no_pair_count; mark++) {
hp = neighbors_without[mark];
agedge(g, tp, hp);
DEGREE(tp)++;
DEGREE(hp)++;
}
}
}
free(neighbors_without);
free(neighbors_with);
}
