int igraph_i_largest_weighted_cliques(const igraph_t *graph,
const igraph_vector_t *vertex_weights, igraph_vector_ptr_t *res)
{
graph_t *g;
igraph_integer_t vcount = igraph_vcount(graph);
if (vcount == 0) {
igraph_vector_ptr_clear(res);
return IGRAPH_SUCCESS;
}
igraph_to_cliquer(graph, &g);
IGRAPH_FINALLY(graph_free, g);
IGRAPH_CHECK(set_weights(vertex_weights, g));
igraph_vector_ptr_clear(res);
igraph_cliquer_opt.user_data = res;
igraph_cliquer_opt.user_function = &collect_cliques_callback;
IGRAPH_FINALLY(free_clique_list, res);
CLIQUER_INTERRUPTABLE(clique_find_all(g, 0, 0, FALSE, &igraph_cliquer_opt));
IGRAPH_FINALLY_CLEAN(1);
graph_free(g);
IGRAPH_FINALLY_CLEAN(1);
return IGRAPH_SUCCESS;
}
int igraph_i_cliquer_cliques(const igraph_t *graph, igraph_vector_ptr_t *res,
igraph_integer_t min_size, igraph_integer_t max_size)
{
graph_t *g;
igraph_integer_t vcount = igraph_vcount(graph);
if (vcount == 0) {
igraph_vector_ptr_clear(res);
return IGRAPH_SUCCESS;
}
if (min_size <= 0) min_size = 1;
if (max_size <= 0) max_size = 0;
if (max_size > 0 && max_size < min_size)
IGRAPH_ERROR("max_size must not be smaller than min_size", IGRAPH_EINVAL);
igraph_to_cliquer(graph, &g);
IGRAPH_FINALLY(graph_free, g);
igraph_vector_ptr_clear(res);
igraph_cliquer_opt.user_data = res;
igraph_cliquer_opt.user_function = &collect_cliques_callback;
IGRAPH_FINALLY(free_clique_list, res);
CLIQUER_INTERRUPTABLE(clique_unweighted_find_all(g, min_size, max_size, /* maximal= */ FALSE, &igraph_cliquer_opt));
IGRAPH_FINALLY_CLEAN(1);
graph_free(g);
IGRAPH_FINALLY_CLEAN(1);
return IGRAPH_SUCCESS;
}
int igraph_largest_cliques(const igraph_t *graph, igraph_vector_ptr_t *res) {
igraph_vector_ptr_clear(res);
IGRAPH_FINALLY(igraph_i_cliques_free_res, res);
IGRAPH_CHECK(igraph_i_maximal_cliques(graph, &igraph_i_largest_cliques_store, (void*)res));
IGRAPH_FINALLY_CLEAN(1);
return IGRAPH_SUCCESS;
}
int igraph_i_weighted_cliques(const igraph_t *graph,
const igraph_vector_t *vertex_weights, igraph_vector_ptr_t *res,
igraph_real_t min_weight, igraph_real_t max_weight, igraph_bool_t maximal)
{
graph_t *g;
igraph_integer_t vcount = igraph_vcount(graph);
if (vcount == 0) {
igraph_vector_ptr_clear(res);
return IGRAPH_SUCCESS;
}
if (min_weight != (int) min_weight) {
IGRAPH_WARNING("Only integer vertex weights are supported; the minimum weight will be truncated to its integer part");
min_weight = (int) min_weight;
}
if (max_weight != (int) max_weight) {
IGRAPH_WARNING("Only integer vertex weights are supported; the maximum weight will be truncated to its integer part");
max_weight = (int) max_weight;
}
if (min_weight <= 0) min_weight = 1;
if (max_weight <= 0) max_weight = 0;
if (max_weight > 0 && max_weight < min_weight)
IGRAPH_ERROR("max_weight must not be smaller than min_weight", IGRAPH_EINVAL);
igraph_to_cliquer(graph, &g);
IGRAPH_FINALLY(graph_free, g);
IGRAPH_CHECK(set_weights(vertex_weights, g));
igraph_vector_ptr_clear(res);
igraph_cliquer_opt.user_data = res;
igraph_cliquer_opt.user_function = &collect_cliques_callback;
IGRAPH_FINALLY(free_clique_list, res);
CLIQUER_INTERRUPTABLE(clique_find_all(g, min_weight, max_weight, maximal, &igraph_cliquer_opt));
IGRAPH_FINALLY_CLEAN(1);
graph_free(g);
IGRAPH_FINALLY_CLEAN(1);
return IGRAPH_SUCCESS;
}
int igraph_i_maximal_or_largest_cliques_or_indsets(const igraph_t *graph,
igraph_vector_ptr_t *res,
igraph_integer_t *clique_number,
igraph_bool_t keep_only_largest,
igraph_bool_t complementer) {
igraph_i_max_ind_vsets_data_t clqdata;
long int no_of_nodes = igraph_vcount(graph), i;
if (igraph_is_directed(graph))
IGRAPH_WARNING("directionality of edges is ignored for directed graphs");
clqdata.matrix_size=no_of_nodes;
clqdata.keep_only_largest=keep_only_largest;
if (complementer)
IGRAPH_CHECK(igraph_adjlist_init_complementer(graph, &clqdata.adj_list, IGRAPH_ALL, 0));
else
IGRAPH_CHECK(igraph_adjlist_init(graph, &clqdata.adj_list, IGRAPH_ALL));
IGRAPH_FINALLY(igraph_adjlist_destroy, &clqdata.adj_list);
clqdata.IS = igraph_Calloc(no_of_nodes, igraph_integer_t);
if (clqdata.IS == 0)
IGRAPH_ERROR("igraph_i_maximal_or_largest_cliques_or_indsets failed", IGRAPH_ENOMEM);
IGRAPH_FINALLY(igraph_free, clqdata.IS);
IGRAPH_VECTOR_INIT_FINALLY(&clqdata.deg, no_of_nodes);
for (i=0; i<no_of_nodes; i++)
VECTOR(clqdata.deg)[i] = igraph_vector_size(igraph_adjlist_get(&clqdata.adj_list, i));
clqdata.buckets = igraph_Calloc(no_of_nodes+1, igraph_set_t);
if (clqdata.buckets == 0)
IGRAPH_ERROR("igraph_maximal_or_largest_cliques_or_indsets failed", IGRAPH_ENOMEM);
IGRAPH_FINALLY(igraph_i_free_set_array, clqdata.buckets);
for (i=0; i<no_of_nodes; i++)
IGRAPH_CHECK(igraph_set_init(&clqdata.buckets[i], 0));
if (res) igraph_vector_ptr_clear(res);
/* Do the show */
clqdata.largest_set_size=0;
IGRAPH_CHECK(igraph_i_maximal_independent_vertex_sets_backtrack(graph, res, &clqdata, 0));
/* Cleanup */
for (i=0; i<no_of_nodes; i++) igraph_set_destroy(&clqdata.buckets[i]);
igraph_adjlist_destroy(&clqdata.adj_list);
igraph_vector_destroy(&clqdata.deg);
igraph_free(clqdata.IS);
igraph_free(clqdata.buckets);
IGRAPH_FINALLY_CLEAN(4);
if (clique_number) *clique_number = clqdata.largest_set_size;
return 0;
}
void igraph_i_cliques_free_res(igraph_vector_ptr_t *res) {
long i, n;
n = igraph_vector_ptr_size(res);
for (i=0; i<n; i++) {
if (VECTOR(*res)[i] != 0) {
igraph_vector_destroy(VECTOR(*res)[i]);
igraph_free(VECTOR(*res)[i]);
}
}
igraph_vector_ptr_clear(res);
}
/**
* \function igraph_maximal_cliques
* \brief Find all maximal cliques of a graph
*
* </para><para>
* A maximal clique is a clique which can't be extended any more by adding a
* new vertex to it.
*
* </para><para>
* If you are only interested in the size of the largest clique in the graph,
* use \ref igraph_clique_number() instead.
*
* </para><para>
* The current implementation uses the Bron-Kerbosch algorithm to find
* the maximal cliques, see: C. Bron and J. Kerbosch. Algorithm 457:
* finding all cliques of an undirected graph. Communications of the ACM
* 16(9):575-577, 1973.
*
* </para><para>The implementation of this function changed between
* igraph 0.5 and 0.6, so the order of the cliques and the order of
* vertices within the cliques will almost surely be different between
* these two versions.
*
* \param graph The input graph.
* \param res Pointer to a pointer vector, the result will be stored
* here, ie. \c res will contain pointers to \c igraph_vector_t
* objects which contain the indices of vertices involved in a clique.
* The pointer vector will be resized if needed but note that the
* objects in the pointer vector will not be freed. Note that vertices
* of a clique may be returned in arbitrary order.
* \param min_size Integer giving the minimum size of the cliques to be
* returned. If negative or zero, no lower bound will be used.
* \param max_size Integer giving the maximum size of the cliques to be
* returned. If negative or zero, no upper bound will be used.
* \return Error code.
*
* \sa \ref igraph_maximal_independent_vertex_sets(), \ref
* igraph_clique_number()
*
* Time complexity: O(3^(|V|/3)) worst case.
*
* \example examples/simple/igraph_maximal_cliques.c
*/
int igraph_maximal_cliques(const igraph_t *graph, igraph_vector_ptr_t *res,
igraph_integer_t min_size, igraph_integer_t max_size) {
igraph_i_maximal_clique_data_t data;
igraph_vector_ptr_clear(res);
IGRAPH_FINALLY(igraph_i_cliques_free_res, res);
if (min_size <= 0 && (max_size <= 0 || max_size >= igraph_vcount(graph))) {
/* Search without size limits */
IGRAPH_CHECK(igraph_i_maximal_cliques(graph, &igraph_i_maximal_cliques_store, (void*)res));
} else {
/* Size-limited search */
data.result = res;
data.min_size = (min_size <= 0 ? 1 : min_size);
data.max_size = (max_size <= 0 ? igraph_vcount(graph) : max_size);
IGRAPH_CHECK(igraph_i_maximal_cliques(graph, &igraph_i_maximal_cliques_store_size_check, (void*)&data));
}
IGRAPH_FINALLY_CLEAN(1);
return IGRAPH_SUCCESS;
}
int igraph_cohesive_blocks(const igraph_t *graph,
igraph_vector_ptr_t *blocks,
igraph_vector_t *cohesion,
igraph_vector_t *parent,
igraph_t *block_tree) {
/* Some implementation comments. Everything is relatively
straightforward, except, that we need to follow the vertex ids
of the various subgraphs, without having to store two-way
mappings at each level. The subgraphs can overlap, this
complicates things a bit.
The 'Q' vector is used as a double ended queue and it contains
the subgraphs to work on in the future. Some other vectors are
associated with it. 'Qparent' gives the parent graph of a graph
in Q. Qmapping gives the mapping of the vertices from the graph
to the parent graph. Qcohesion is the vertex connectivity of the
graph.
Qptr is an integer and points to the next graph to work on.
*/
igraph_vector_ptr_t Q;
igraph_vector_ptr_t Qmapping;
igraph_vector_long_t Qparent;
igraph_vector_long_t Qcohesion;
igraph_vector_bool_t Qcheck;
long int Qptr=0;
igraph_integer_t conn;
igraph_bool_t is_simple;
igraph_t *graph_copy;
igraph_vector_ptr_t separators;
igraph_vector_t compvertices;
igraph_vector_long_t components;
igraph_vector_bool_t marked;
igraph_vector_long_t compid;
igraph_dqueue_t bfsQ;
igraph_vector_t neis;
if (igraph_is_directed(graph)) {
IGRAPH_ERROR("Cohesive blocking only works on undirected graphs",
IGRAPH_EINVAL);
}
IGRAPH_CHECK(igraph_is_simple(graph, &is_simple));
if (!is_simple) {
IGRAPH_ERROR("Cohesive blocking only works on simple graphs",
IGRAPH_EINVAL);
}
IGRAPH_STATUS("Starting cohesive block calculation.\n", 0);
if (blocks) { igraph_vector_ptr_clear(blocks); }
if (cohesion) { igraph_vector_clear(cohesion); }
if (parent) { igraph_vector_clear(parent); }
IGRAPH_CHECK(igraph_vector_ptr_init(&Q, 1));
IGRAPH_FINALLY(igraph_vector_ptr_destroy, &Q);
IGRAPH_FINALLY(igraph_i_cohesive_blocks_free, &Q);
IGRAPH_CHECK(igraph_vector_ptr_init(&Qmapping, 1));
IGRAPH_FINALLY(igraph_vector_ptr_destroy, &Qmapping);
IGRAPH_FINALLY(igraph_i_cohesive_blocks_free2, &Qmapping);
IGRAPH_CHECK(igraph_vector_long_init(&Qparent, 1));
IGRAPH_FINALLY(igraph_vector_long_destroy, &Qparent);
IGRAPH_CHECK(igraph_vector_long_init(&Qcohesion, 1));
IGRAPH_FINALLY(igraph_vector_long_destroy, &Qcohesion);
IGRAPH_CHECK(igraph_vector_bool_init(&Qcheck, 1));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &Qcheck);
IGRAPH_CHECK(igraph_vector_ptr_init(&separators, 0));
IGRAPH_FINALLY(igraph_vector_ptr_destroy, &separators);
IGRAPH_VECTOR_INIT_FINALLY(&compvertices, 0);
IGRAPH_CHECK(igraph_vector_bool_init(&marked, 0));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &marked);
IGRAPH_VECTOR_INIT_FINALLY(&neis, 0);
IGRAPH_CHECK(igraph_dqueue_init(&bfsQ, 100));
IGRAPH_FINALLY(igraph_dqueue_destroy, &bfsQ);
IGRAPH_CHECK(igraph_vector_long_init(&compid, 0));
IGRAPH_FINALLY(igraph_vector_long_destroy, &compid);
IGRAPH_CHECK(igraph_vector_long_init(&components, 0));
IGRAPH_FINALLY(igraph_vector_long_destroy, &components);
/* Put the input graph in the queue */
graph_copy=igraph_Calloc(1, igraph_t);
if (!graph_copy) {
IGRAPH_ERROR("Cannot do cohesive blocking", IGRAPH_ENOMEM);
}
IGRAPH_CHECK(igraph_copy(graph_copy, graph));
VECTOR(Q)[0] = graph_copy;
VECTOR(Qmapping)[0] = 0; /* Identity mapping */
VECTOR(Qparent)[0] = -1; /* Has no parent */
IGRAPH_CHECK(igraph_vertex_connectivity(graph, &conn, /*checks=*/ 1));
VECTOR(Qcohesion)[0] = conn;
VECTOR(Qcheck)[0] = 0;
/* Then work until the queue is empty */
while (Qptr < igraph_vector_ptr_size(&Q)) {
igraph_t *mygraph=VECTOR(Q)[Qptr];
igraph_bool_t mycheck=VECTOR(Qcheck)[Qptr];
long int mynodes=igraph_vcount(mygraph);
long int i, nsep;
long int no, kept=0;
long int cptr=0;
long int nsepv=0;
igraph_bool_t addedsep=0;
IGRAPH_STATUSF(("Candidate %li: %li vertices,",
0, Qptr, mynodes));
IGRAPH_ALLOW_INTERRUPTION();
/* Get the separators */
IGRAPH_CHECK(igraph_minimum_size_separators(mygraph, &separators));
IGRAPH_FINALLY(igraph_i_cohesive_blocks_free3, &separators);
nsep=igraph_vector_ptr_size(&separators);
IGRAPH_STATUSF((" %li separators,", 0, nsep));
/* Remove them from the graph, also mark them */
IGRAPH_CHECK(igraph_vector_bool_resize(&marked, mynodes));
igraph_vector_bool_null(&marked);
for (i=0; i<nsep; i++) {
igraph_vector_t *v=VECTOR(separators)[i];
long int j, n=igraph_vector_size(v);
for (j=0; j<n; j++) {
long int vv=(long int) VECTOR(*v)[j];
if (!VECTOR(marked)[vv]) {
nsepv++;
VECTOR(marked)[vv] = 1;
}
}
}
/* Find the connected components, omitting the separator vertices,
but including the neighboring separator vertices
*/
IGRAPH_CHECK(igraph_i_cb_components(mygraph, &marked,
&components, &no,
&compid, &bfsQ, &neis));
/* Add the separator vertices themselves, as another component,
but only if there is at least one vertex not included in any
separator. */
if (nsepv != mynodes) {
addedsep=1;
for (i=0; i<mynodes; i++) {
if (VECTOR(marked)[i]) {
IGRAPH_CHECK(igraph_vector_long_push_back(&components, i));
}
}
IGRAPH_CHECK(igraph_vector_long_push_back(&components, -1));
no++;
}
IGRAPH_STATUSF((" %li new candidates,", 0, no));
for (i=0; i<no; i++) {
igraph_vector_t *newmapping;
igraph_t *newgraph;
igraph_integer_t maxdeg;
igraph_vector_clear(&compvertices);
while (1) {
long int v=VECTOR(components)[cptr++];
if (v < 0) { break; }
IGRAPH_CHECK(igraph_vector_push_back(&compvertices, v));
}
newmapping=igraph_Calloc(1, igraph_vector_t);
if (!newmapping) {
IGRAPH_ERROR("Cannot do cohesive blocking", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, newmapping);
IGRAPH_VECTOR_INIT_FINALLY(newmapping, 0);
newgraph=igraph_Calloc(1, igraph_t);
if (!newgraph) {
IGRAPH_ERROR("Cannot do cohesive blocking", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, newgraph);
IGRAPH_CHECK(igraph_induced_subgraph_map(mygraph, newgraph,
igraph_vss_vector(&compvertices),
IGRAPH_SUBGRAPH_AUTO,
/*map=*/ 0,
/*invmap=*/ newmapping));
IGRAPH_FINALLY(igraph_destroy, newgraph);
IGRAPH_CHECK(igraph_maxdegree(newgraph, &maxdeg, igraph_vss_all(),
IGRAPH_ALL, IGRAPH_LOOPS));
if (maxdeg > VECTOR(Qcohesion)[Qptr]) {
igraph_integer_t newconn;
kept++;
IGRAPH_CHECK(igraph_vector_ptr_push_back(&Q, newgraph));
IGRAPH_FINALLY_CLEAN(2);
IGRAPH_CHECK(igraph_vector_ptr_push_back(&Qmapping, newmapping));
IGRAPH_FINALLY_CLEAN(2);
IGRAPH_CHECK(igraph_vertex_connectivity(newgraph, &newconn,
/*checks=*/ 1));
IGRAPH_CHECK(igraph_vector_long_push_back(&Qcohesion, newconn));
IGRAPH_CHECK(igraph_vector_long_push_back(&Qparent, Qptr));
IGRAPH_CHECK(igraph_vector_bool_push_back(&Qcheck,
mycheck || addedsep));
} else {
igraph_destroy(newgraph);
igraph_free(newgraph);
igraph_vector_destroy(newmapping);
igraph_free(newmapping);
IGRAPH_FINALLY_CLEAN(4);
}
}
IGRAPH_STATUSF((" keeping %li.\n", 0, kept));
igraph_destroy(mygraph);
igraph_free(mygraph);
VECTOR(Q)[Qptr] = 0;
igraph_i_cohesive_blocks_free3(&separators);
IGRAPH_FINALLY_CLEAN(1);
Qptr++;
}
igraph_vector_long_destroy(&components);
igraph_vector_long_destroy(&compid);
igraph_dqueue_destroy(&bfsQ);
igraph_vector_destroy(&neis);
igraph_vector_bool_destroy(&marked);
igraph_vector_destroy(&compvertices);
igraph_vector_ptr_destroy(&separators);
IGRAPH_FINALLY_CLEAN(7);
if (blocks || cohesion || parent || block_tree) {
igraph_integer_t noblocks=(igraph_integer_t) Qptr, badblocks=0;
igraph_vector_bool_t removed;
long int i, resptr=0;
igraph_vector_long_t rewritemap;
IGRAPH_CHECK(igraph_vector_bool_init(&removed, noblocks));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &removed);
IGRAPH_CHECK(igraph_vector_long_init(&rewritemap, noblocks));
IGRAPH_FINALLY(igraph_vector_long_destroy, &rewritemap);
for (i=1; i<noblocks; i++) {
long int p=VECTOR(Qparent)[i];
while (VECTOR(removed)[p]) { p=VECTOR(Qparent)[p]; }
if (VECTOR(Qcohesion)[p] >= VECTOR(Qcohesion)[i]) {
VECTOR(removed)[i]=1;
badblocks++;
}
}
/* Rewrite the mappings */
for (i=1; i<Qptr; i++) {
long int p=VECTOR(Qparent)[i];
igraph_vector_t *mapping=VECTOR(Qmapping)[i];
igraph_vector_t *pmapping=VECTOR(Qmapping)[p];
long int j, n=igraph_vector_size(mapping);
if (!pmapping) { continue; }
for (j=0; j<n; j++) {
long int v=(long int) VECTOR(*mapping)[j];
VECTOR(*mapping)[j] = VECTOR(*pmapping)[v];
}
}
/* Because we also put the separator vertices in the queue, it is
not ensured that the found blocks are not subsets of each other.
We check this now. */
for (i=1; i<noblocks; i++) {
long int j, ic;
igraph_vector_t *ivec;
if (!VECTOR(Qcheck)[i] || VECTOR(removed)[i]) { continue; }
ivec=VECTOR(Qmapping)[i];
ic=VECTOR(Qcohesion)[i];
for (j=1; j<noblocks; j++) {
igraph_vector_t *jvec;
long int jc;
if (j==i || !VECTOR(Qcheck)[j] || VECTOR(removed)[j]) { continue; }
jvec=VECTOR(Qmapping)[j];
jc=VECTOR(Qcohesion)[j];
if (igraph_i_cb_isin(ivec, jvec) && jc >= ic) {
badblocks++;
VECTOR(removed)[i]=1;
break;
}
}
}
noblocks -= badblocks;
if (blocks) { IGRAPH_CHECK(igraph_vector_ptr_resize(blocks, noblocks)); }
if (cohesion) { IGRAPH_CHECK(igraph_vector_resize(cohesion, noblocks)); }
if (parent) { IGRAPH_CHECK(igraph_vector_resize(parent, noblocks)); }
for (i=0; i<Qptr; i++) {
if (VECTOR(removed)[i]) {
IGRAPH_STATUSF(("Candidate %li ignored.\n", 0, i));
continue;
} else {
IGRAPH_STATUSF(("Candidate %li is a cohesive (sub)block\n", 0, i));
}
VECTOR(rewritemap)[i] = resptr;
if (cohesion) { VECTOR(*cohesion)[resptr]=VECTOR(Qcohesion)[i]; }
if (parent || block_tree) {
long int p=VECTOR(Qparent)[i];
while (p>=0 && VECTOR(removed)[p]) { p=VECTOR(Qparent)[p]; }
if (p>=0) { p=VECTOR(rewritemap)[p]; }
VECTOR(Qparent)[i]=p;
if (parent) { VECTOR(*parent)[resptr]=p; }
}
if (blocks) {
VECTOR(*blocks)[resptr]=VECTOR(Qmapping)[i];
VECTOR(Qmapping)[i]=0;
}
resptr++;
}
/* Plus the original graph */
if (blocks) {
igraph_vector_t *orig=igraph_Calloc(1, igraph_vector_t);
if (!orig) {
IGRAPH_ERROR("Cannot do cohesive blocking", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, orig);
IGRAPH_CHECK(igraph_vector_init_seq(orig, 0, igraph_vcount(graph)-1));
VECTOR(*blocks)[0]=orig;
IGRAPH_FINALLY_CLEAN(1);
}
if (block_tree) {
igraph_vector_t edges;
long int eptr=0;
IGRAPH_VECTOR_INIT_FINALLY(&edges, noblocks*2-2);
for (i=1; i<Qptr; i++) {
if (VECTOR(removed)[i]) { continue; }
VECTOR(edges)[eptr++] = VECTOR(Qparent)[i];
VECTOR(edges)[eptr++] = VECTOR(rewritemap)[i];
}
IGRAPH_CHECK(igraph_create(block_tree, &edges, noblocks,
IGRAPH_DIRECTED));
igraph_vector_destroy(&edges);
IGRAPH_FINALLY_CLEAN(1);
}
igraph_vector_long_destroy(&rewritemap);
igraph_vector_bool_destroy(&removed);
IGRAPH_FINALLY_CLEAN(2);
}
igraph_vector_bool_destroy(&Qcheck);
igraph_vector_long_destroy(&Qcohesion);
igraph_vector_long_destroy(&Qparent);
igraph_i_cohesive_blocks_free2(&Qmapping);
IGRAPH_FINALLY_CLEAN(4);
igraph_vector_ptr_destroy(&Qmapping);
igraph_vector_ptr_destroy(&Q);
IGRAPH_FINALLY_CLEAN(3); /* + the elements of Q, they were
already destroyed */
IGRAPH_STATUS("Cohesive blocking done.\n", 0);
return 0;
}
int igraph_i_maximal_independent_vertex_sets_backtrack(const igraph_t *graph,
igraph_vector_ptr_t *res,
igraph_i_max_ind_vsets_data_t *clqdata,
igraph_integer_t level) {
long int v1, v2, v3, c, j, k;
igraph_vector_t *neis1, *neis2;
igraph_bool_t f;
igraph_integer_t j1;
long int it_state;
IGRAPH_ALLOW_INTERRUPTION();
if (level >= clqdata->matrix_size-1) {
igraph_integer_t size=0;
if (res) {
igraph_vector_t *vec;
vec = igraph_Calloc(1, igraph_vector_t);
if (vec == 0)
IGRAPH_ERROR("igraph_i_maximal_independent_vertex_sets failed", IGRAPH_ENOMEM);
IGRAPH_VECTOR_INIT_FINALLY(vec, 0);
for (v1=0; v1<clqdata->matrix_size; v1++)
if (clqdata->IS[v1] == 0) {
IGRAPH_CHECK(igraph_vector_push_back(vec, v1));
}
size=igraph_vector_size(vec);
if (!clqdata->keep_only_largest)
IGRAPH_CHECK(igraph_vector_ptr_push_back(res, vec));
else {
if (size > clqdata->largest_set_size) {
/* We are keeping only the largest sets, and we've found one that's
* larger than all previous sets, so we have to clear the list */
j=igraph_vector_ptr_size(res);
for (v1=0; v1<j; v1++) {
igraph_vector_destroy(VECTOR(*res)[v1]);
free(VECTOR(*res)[v1]);
}
igraph_vector_ptr_clear(res);
IGRAPH_CHECK(igraph_vector_ptr_push_back(res, vec));
} else if (size == clqdata->largest_set_size) {
IGRAPH_CHECK(igraph_vector_ptr_push_back(res, vec));
} else {
igraph_vector_destroy(vec);
free(vec);
}
}
IGRAPH_FINALLY_CLEAN(1);
} else {
for (v1=0, size=0; v1<clqdata->matrix_size; v1++)
if (clqdata->IS[v1] == 0) size++;
}
if (size>clqdata->largest_set_size) clqdata->largest_set_size=size;
} else {
v1 = level+1;
/* Count the number of vertices with an index less than v1 that have
* an IS value of zero */
neis1 = igraph_adjlist_get(&clqdata->adj_list, v1);
c = 0;
j = 0;
while (j<VECTOR(clqdata->deg)[v1] && (v2=VECTOR(*neis1)[j]) <= level) {
if (clqdata->IS[v2] == 0) c++;
j++;
}
if (c == 0) {
/* If there are no such nodes... */
j = 0;
while (j<VECTOR(clqdata->deg)[v1] && (v2=VECTOR(*neis1)[j]) <= level) {
clqdata->IS[v2]++;
j++;
}
IGRAPH_CHECK(igraph_i_maximal_independent_vertex_sets_backtrack(graph,res,clqdata,v1));
j = 0;
while (j<VECTOR(clqdata->deg)[v1] && (v2=VECTOR(*neis1)[j]) <= level) {
clqdata->IS[v2]--;
j++;
}
} else {
/* If there are such nodes, store the count in the IS value of v1 */
clqdata->IS[v1] = c;
IGRAPH_CHECK(igraph_i_maximal_independent_vertex_sets_backtrack(graph,res,clqdata,v1));
clqdata->IS[v1] = 0;
f=1;
j=0;
while (j<VECTOR(clqdata->deg)[v1] && (v2=VECTOR(*neis1)[j]) <= level) {
if (clqdata->IS[v2] == 0) {
IGRAPH_CHECK(igraph_set_add(&clqdata->buckets[v1], j));
neis2 = igraph_adjlist_get(&clqdata->adj_list, v2);
k = 0;
while (k<VECTOR(clqdata->deg)[v2] && (v3=VECTOR(*neis2)[k])<=level) {
clqdata->IS[v3]--;
if (clqdata->IS[v3] == 0) f=0;
k++;
}
}
clqdata->IS[v2]++;
j++;
}
if (f)
IGRAPH_CHECK(igraph_i_maximal_independent_vertex_sets_backtrack(graph,res,clqdata,v1));
j=0;
while (j<VECTOR(clqdata->deg)[v1] && (v2=VECTOR(*neis1)[j]) <= level) {
clqdata->IS[v2]--;
j++;
}
it_state=0;
while (igraph_set_iterate(&clqdata->buckets[v1], &it_state, &j1)) {
j=(long)j1;
v2=VECTOR(*neis1)[j];
neis2 = igraph_adjlist_get(&clqdata->adj_list, v2);
k = 0;
while (k<VECTOR(clqdata->deg)[v2] && (v3=VECTOR(*neis2)[k])<=level) {
clqdata->IS[v3]++;
k++;
}
}
igraph_set_clear(&clqdata->buckets[v1]);
}
}
return 0;
}
/* Internal function for calculating cliques or independent vertex sets.
* They are practically the same except that the complementer of the graph
* should be used in the latter case.
*/
int igraph_i_cliques(const igraph_t *graph, igraph_vector_ptr_t *res,
igraph_integer_t min_size, igraph_integer_t max_size,
igraph_bool_t independent_vertices) {
igraph_integer_t no_of_nodes;
igraph_vector_t neis;
igraph_real_t *member_storage=0, *new_member_storage, *c1;
long int i, j, k, clique_count, old_clique_count;
if (igraph_is_directed(graph))
IGRAPH_WARNING("directionality of edges is ignored for directed graphs");
no_of_nodes = igraph_vcount(graph);
if (min_size < 0) { min_size = 0; }
if (max_size > no_of_nodes || max_size <= 0) { max_size = no_of_nodes; }
igraph_vector_ptr_clear(res);
IGRAPH_VECTOR_INIT_FINALLY(&neis, 0);
IGRAPH_FINALLY(igraph_i_cliques_free_res, res);
/* Will be resized later, if needed. */
member_storage=igraph_Calloc(1, igraph_real_t);
if (member_storage==0) {
IGRAPH_ERROR("cliques failed", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, member_storage);
/* Find all 1-cliques: every vertex will be a clique */
new_member_storage=igraph_Calloc(no_of_nodes, igraph_real_t);
if (new_member_storage==0) {
IGRAPH_ERROR("cliques failed", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, new_member_storage);
for (i=0; i<no_of_nodes; i++) {
new_member_storage[i] = i;
}
clique_count = no_of_nodes;
old_clique_count = 0;
/* Add size 1 cliques if requested */
if (min_size <= 1) {
IGRAPH_CHECK(igraph_vector_ptr_resize(res, no_of_nodes));
igraph_vector_ptr_null(res);
for (i=0; i<no_of_nodes; i++) {
igraph_vector_t *p=igraph_Calloc(1, igraph_vector_t);
if (p==0) {
IGRAPH_ERROR("cliques failed", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, p);
IGRAPH_CHECK(igraph_vector_init(p, 1));
VECTOR(*p)[0]=i;
VECTOR(*res)[i]=p;
IGRAPH_FINALLY_CLEAN(1);
}
}
for (i=2; i<=max_size && clique_count > 1; i++) {
/* Here new_member_storage contains the cliques found in the previous
iteration. Save this into member_storage, might be needed later */
c1=member_storage;
member_storage=new_member_storage;
new_member_storage=c1;
old_clique_count=clique_count;
IGRAPH_ALLOW_INTERRUPTION();
/* Calculate the cliques */
IGRAPH_FINALLY_CLEAN(2);
IGRAPH_CHECK(igraph_i_find_k_cliques(graph, i, member_storage,
&new_member_storage,
old_clique_count,
&clique_count,
&neis,
independent_vertices));
IGRAPH_FINALLY(igraph_free, member_storage);
IGRAPH_FINALLY(igraph_free, new_member_storage);
/* Add the cliques just found to the result if requested */
if (i>=min_size && i<=max_size) {
for (j=0, k=0; j<clique_count; j++, k+=i) {
igraph_vector_t *p=igraph_Calloc(1, igraph_vector_t);
if (p==0) {
IGRAPH_ERROR("cliques failed", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, p);
IGRAPH_CHECK(igraph_vector_init_copy(p, &new_member_storage[k], i));
IGRAPH_FINALLY(igraph_vector_destroy, p);
IGRAPH_CHECK(igraph_vector_ptr_push_back(res, p));
IGRAPH_FINALLY_CLEAN(2);
}
}
} /* i <= max_size && clique_count != 0 */
igraph_free(member_storage);
igraph_free(new_member_storage);
igraph_vector_destroy(&neis);
IGRAPH_FINALLY_CLEAN(4); /* 3 here, +1 is igraph_i_cliques_free_res */
return 0;
}
int igraph_biconnected_components(const igraph_t *graph,
igraph_integer_t *no,
igraph_vector_ptr_t *tree_edges,
igraph_vector_ptr_t *component_edges,
igraph_vector_ptr_t *components,
igraph_vector_t *articulation_points) {
long int no_of_nodes=igraph_vcount(graph);
igraph_vector_long_t nextptr;
igraph_vector_long_t num, low;
igraph_vector_bool_t found;
igraph_vector_int_t *adjedges;
igraph_stack_t path;
igraph_vector_t edgestack;
igraph_inclist_t inclist;
long int i, counter, rootdfs=0;
igraph_vector_long_t vertex_added;
long int comps=0;
igraph_vector_ptr_t *mycomponents=components, vcomponents;
IGRAPH_CHECK(igraph_vector_long_init(&nextptr, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &nextptr);
IGRAPH_CHECK(igraph_vector_long_init(&num, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &num);
IGRAPH_CHECK(igraph_vector_long_init(&low, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &low);
IGRAPH_CHECK(igraph_vector_bool_init(&found, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &found);
IGRAPH_CHECK(igraph_stack_init(&path, 100));
IGRAPH_FINALLY(igraph_stack_destroy, &path);
IGRAPH_VECTOR_INIT_FINALLY(&edgestack, 0);
IGRAPH_CHECK(igraph_vector_reserve(&edgestack, 100));
IGRAPH_CHECK(igraph_inclist_init(graph, &inclist, IGRAPH_ALL));
IGRAPH_FINALLY(igraph_inclist_destroy, &inclist);
IGRAPH_CHECK(igraph_vector_long_init(&vertex_added, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &vertex_added);
if (no) {
*no=0;
}
if (tree_edges) {
igraph_vector_ptr_clear(tree_edges);
}
if (components) {
igraph_vector_ptr_clear(components);
}
if (component_edges) {
igraph_vector_ptr_clear(component_edges);
}
if (articulation_points) {
igraph_vector_clear(articulation_points);
}
if (component_edges && !components) {
mycomponents=&vcomponents;
IGRAPH_CHECK(igraph_vector_ptr_init(mycomponents, 0));
IGRAPH_FINALLY(igraph_i_free_vectorlist, mycomponents);
}
for (i=0; i<no_of_nodes; i++) {
if (VECTOR(low)[i] != 0) { continue; } /* already visited */
IGRAPH_ALLOW_INTERRUPTION();
IGRAPH_CHECK(igraph_stack_push(&path, i));
counter=1;
rootdfs=0;
VECTOR(low)[i]=VECTOR(num)[i]=counter++;
while (!igraph_stack_empty(&path)) {
long int n;
long int act=(long int) igraph_stack_top(&path);
long int actnext=VECTOR(nextptr)[act];
adjedges=igraph_inclist_get(&inclist, act);
n=igraph_vector_int_size(adjedges);
if (actnext < n) {
/* Step down (maybe) */
long int edge=(long int) VECTOR(*adjedges)[actnext];
long int nei=IGRAPH_OTHER(graph, edge, act);
if (VECTOR(low)[nei] == 0) {
if (act==i) { rootdfs++; }
IGRAPH_CHECK(igraph_vector_push_back(&edgestack, edge));
IGRAPH_CHECK(igraph_stack_push(&path, nei));
VECTOR(low)[nei] = VECTOR(num)[nei]=counter++;
} else {
/* Update low value if needed */
if (VECTOR(num)[nei] < VECTOR(low)[act]) {
VECTOR(low)[act]=VECTOR(num)[nei];
}
}
VECTOR(nextptr)[act] += 1;
} else {
/* Step up */
igraph_stack_pop(&path);
if (!igraph_stack_empty(&path)) {
long int prev=(long int) igraph_stack_top(&path);
/* Update LOW value if needed */
if (VECTOR(low)[act] < VECTOR(low)[prev]) {
VECTOR(low)[prev] = VECTOR(low)[act];
}
/* Check for articulation point */
if (VECTOR(low)[act] >= VECTOR(num)[prev]) {
if (articulation_points && !VECTOR(found)[prev]
&& prev != i /* the root */) {
IGRAPH_CHECK(igraph_vector_push_back(articulation_points, prev));
VECTOR(found)[prev] = 1;
}
if (no) { *no += 1; }
/*------------------------------------*/
/* Record the biconnected component just found */
if (tree_edges || mycomponents) {
igraph_vector_t *v = 0, *v2 = 0;
comps++;
if (tree_edges) {
v=igraph_Calloc(1, igraph_vector_t);
if (!v) { IGRAPH_ERROR("Out of memory", IGRAPH_ENOMEM); }
IGRAPH_CHECK(igraph_vector_init(v, 0));
IGRAPH_FINALLY(igraph_vector_destroy, v);
}
if (mycomponents) {
v2=igraph_Calloc(1, igraph_vector_t);
if (!v2) { IGRAPH_ERROR("Out of memory", IGRAPH_ENOMEM); }
IGRAPH_CHECK(igraph_vector_init(v2, 0));
IGRAPH_FINALLY(igraph_vector_destroy, v2);
}
while (!igraph_vector_empty(&edgestack)) {
long int e=(long int) igraph_vector_pop_back(&edgestack);
long int from=IGRAPH_FROM(graph,e);
long int to=IGRAPH_TO(graph,e);
if (tree_edges) {
IGRAPH_CHECK(igraph_vector_push_back(v, e));
}
if (mycomponents) {
if (VECTOR(vertex_added)[from] != comps) {
VECTOR(vertex_added)[from] = comps;
IGRAPH_CHECK(igraph_vector_push_back(v2, from));
}
if (VECTOR(vertex_added)[to] != comps) {
VECTOR(vertex_added)[to] = comps;
IGRAPH_CHECK(igraph_vector_push_back(v2, to));
}
}
if (from==prev || to==prev) {
break;
}
}
if (mycomponents) {
IGRAPH_CHECK(igraph_vector_ptr_push_back(mycomponents, v2));
IGRAPH_FINALLY_CLEAN(1);
}
if (tree_edges) {
IGRAPH_CHECK(igraph_vector_ptr_push_back(tree_edges, v));
IGRAPH_FINALLY_CLEAN(1);
}
if (component_edges) {
igraph_vector_t *nodes=VECTOR(*mycomponents)[comps-1];
igraph_vector_t *vv=igraph_Calloc(1, igraph_vector_t);
long int ii, no_vert=igraph_vector_size(nodes);
if (!vv) { IGRAPH_ERROR("Out of memory", IGRAPH_ENOMEM); }
IGRAPH_CHECK(igraph_vector_init(vv, 0));
IGRAPH_FINALLY(igraph_vector_destroy, vv);
for (ii=0; ii<no_vert; ii++) {
long int vert=(long int) VECTOR(*nodes)[ii];
igraph_vector_int_t *edges=igraph_inclist_get(&inclist,
vert);
long int j, nn=igraph_vector_int_size(edges);
for (j=0; j<nn; j++) {
long int e=(long int) VECTOR(*edges)[j];
long int nei=IGRAPH_OTHER(graph, e, vert);
if (VECTOR(vertex_added)[nei] == comps && nei<vert) {
IGRAPH_CHECK(igraph_vector_push_back(vv, e));
}
}
}
IGRAPH_CHECK(igraph_vector_ptr_push_back(component_edges, vv));
IGRAPH_FINALLY_CLEAN(1);
}
} /* record component if requested */
/*------------------------------------*/
}
} /* !igraph_stack_empty(&path) */
}
} /* !igraph_stack_empty(&path) */
if (articulation_points && rootdfs >= 2) {
IGRAPH_CHECK(igraph_vector_push_back(articulation_points, i));
}
} /* i < no_of_nodes */
if (mycomponents != components) {
igraph_i_free_vectorlist(mycomponents);
IGRAPH_FINALLY_CLEAN(1);
}
igraph_vector_long_destroy(&vertex_added);
igraph_inclist_destroy(&inclist);
igraph_vector_destroy(&edgestack);
igraph_stack_destroy(&path);
igraph_vector_bool_destroy(&found);
igraph_vector_long_destroy(&low);
igraph_vector_long_destroy(&num);
igraph_vector_long_destroy(&nextptr);
IGRAPH_FINALLY_CLEAN(8);
return 0;
}
int igraph_decompose(const igraph_t *graph, igraph_vector_ptr_t *components,
igraph_connectedness_t mode,
long int maxcompno, long int minelements) {
long int actstart;
long int no_of_nodes=igraph_vcount(graph);
long int resco=0; /* number of graphs created so far */
char *already_added;
igraph_dqueue_t q;
igraph_vector_t verts;
igraph_vector_t neis;
long int i;
igraph_t *newg;
if (!igraph_is_directed(graph)) {
mode=IGRAPH_WEAK;
}
if (mode != IGRAPH_WEAK) {
IGRAPH_ERROR("only 'IGRAPH_WEAK' is implemented", IGRAPH_EINVAL);
}
if (maxcompno<0) {
maxcompno=LONG_MAX;
}
igraph_vector_ptr_clear(components);
IGRAPH_FINALLY(igraph_decompose_destroy, components);
already_added=igraph_Calloc(no_of_nodes, char);
if (already_added==0) {
IGRAPH_ERROR("Cannot decompose graph", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, already_added);
IGRAPH_CHECK(igraph_dqueue_init(&q, 100));
IGRAPH_FINALLY(igraph_dqueue_destroy, &q);
IGRAPH_VECTOR_INIT_FINALLY(&verts, 0);
IGRAPH_VECTOR_INIT_FINALLY(&neis, 0);
for(actstart=0; resco<maxcompno && actstart < no_of_nodes; actstart++) {
if (already_added[actstart]) { continue; }
IGRAPH_ALLOW_INTERRUPTION();
igraph_vector_clear(&verts);
already_added[actstart]=1;
IGRAPH_CHECK(igraph_vector_push_back(&verts, actstart));
IGRAPH_CHECK(igraph_dqueue_push(&q, actstart));
while (!igraph_dqueue_empty(&q) ) {
long int actvert=(long int) igraph_dqueue_pop(&q);
IGRAPH_CHECK(igraph_neighbors(graph, &neis, (igraph_integer_t) actvert,
IGRAPH_ALL));
for (i=0; i<igraph_vector_size(&neis); i++) {
long int neighbor=(long int) VECTOR(neis)[i];
if (already_added[neighbor]==1) { continue; }
IGRAPH_CHECK(igraph_dqueue_push(&q, neighbor));
IGRAPH_CHECK(igraph_vector_push_back(&verts, neighbor));
already_added[neighbor]=1;
}
}
/* ok, we have a component */
if (igraph_vector_size(&verts)<minelements) { continue; }
newg=igraph_Calloc(1, igraph_t);
if (newg==0) {
IGRAPH_ERROR("Cannot decompose graph", IGRAPH_ENOMEM);
}
IGRAPH_CHECK(igraph_vector_ptr_push_back(components, newg));
IGRAPH_CHECK(igraph_induced_subgraph(graph, newg,
igraph_vss_vector(&verts),
IGRAPH_SUBGRAPH_AUTO));
resco++;
} /* for actstart++ */
igraph_vector_destroy(&neis);
igraph_vector_destroy(&verts);
igraph_dqueue_destroy(&q);
igraph_free(already_added);
IGRAPH_FINALLY_CLEAN(5); /* + components */
return 0;
}
int igraph_biconnected_components(const igraph_t *graph,
igraph_integer_t *no,
igraph_vector_ptr_t *components,
igraph_vector_t *articulation_points) {
long int no_of_nodes=igraph_vcount(graph);
igraph_vector_long_t nextptr;
igraph_vector_long_t num, low;
igraph_vector_bool_t found;
igraph_vector_t *adjedges;
igraph_stack_t path;
igraph_vector_t edgestack;
igraph_adjedgelist_t adjedgelist;
long int i, counter, rootdfs=0;
IGRAPH_CHECK(igraph_vector_long_init(&nextptr, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &nextptr);
IGRAPH_CHECK(igraph_vector_long_init(&num, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &num);
IGRAPH_CHECK(igraph_vector_long_init(&low, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &low);
IGRAPH_CHECK(igraph_vector_bool_init(&found, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &found);
IGRAPH_CHECK(igraph_stack_init(&path, 100));
IGRAPH_FINALLY(igraph_stack_destroy, &path);
IGRAPH_VECTOR_INIT_FINALLY(&edgestack, 0);
IGRAPH_CHECK(igraph_vector_reserve(&edgestack, 100));
IGRAPH_CHECK(igraph_adjedgelist_init(graph, &adjedgelist, IGRAPH_ALL));
IGRAPH_FINALLY(igraph_adjedgelist_destroy, &adjedgelist);
if (no) {
*no=0;
}
if (components) {
igraph_vector_ptr_clear(components);
}
if (articulation_points) {
igraph_vector_clear(articulation_points);
}
for (i=0; i<no_of_nodes; i++) {
if (VECTOR(low)[i] != 0) {
continue; /* already visited */
}
IGRAPH_ALLOW_INTERRUPTION();
IGRAPH_CHECK(igraph_stack_push(&path, i));
counter=1;
rootdfs=0;
VECTOR(low)[i]=VECTOR(num)[i]=counter++;
while (!igraph_stack_empty(&path)) {
long int n;
long int act=igraph_stack_top(&path);
long int actnext=VECTOR(nextptr)[act];
adjedges=igraph_adjedgelist_get(&adjedgelist, act);
n=igraph_vector_size(adjedges);
if (actnext < n) {
/* Step down (maybe) */
long int edge=VECTOR(*adjedges)[actnext];
long int nei=IGRAPH_OTHER(graph, edge, act);
if (VECTOR(low)[nei] == 0) {
if (act==i) {
rootdfs++;
}
IGRAPH_CHECK(igraph_vector_push_back(&edgestack, edge));
IGRAPH_CHECK(igraph_stack_push(&path, nei));
VECTOR(low)[nei] = VECTOR(num)[nei]=counter++;
} else {
/* Update low value if needed */
if (VECTOR(num)[nei] < VECTOR(low)[act]) {
VECTOR(low)[act]=VECTOR(num)[nei];
}
}
VECTOR(nextptr)[act] += 1;
} else {
/* Step up */
igraph_stack_pop(&path);
if (!igraph_stack_empty(&path)) {
long int prev=igraph_stack_top(&path);
/* Update LOW value if needed */
if (VECTOR(low)[act] < VECTOR(low)[prev]) {
VECTOR(low)[prev] = VECTOR(low)[act];
}
/* Check for articulation point */
if (VECTOR(low)[act] >= VECTOR(num)[prev]) {
if (articulation_points && !VECTOR(found)[prev]
&& prev != i /* the root */) {
IGRAPH_CHECK(igraph_vector_push_back(articulation_points, prev));
VECTOR(found)[prev] = 1;
}
if (no) {
*no += 1;
}
if (components) {
igraph_vector_t *v=igraph_Calloc(1, igraph_vector_t);
IGRAPH_CHECK(igraph_vector_init(v, 0));
while (!igraph_vector_empty(&edgestack)) {
long int e=igraph_vector_pop_back(&edgestack);
IGRAPH_CHECK(igraph_vector_push_back(v, e));
if (IGRAPH_FROM(graph,e)==prev || IGRAPH_TO(graph,e)==prev) {
break;
}
}
IGRAPH_CHECK(igraph_vector_ptr_push_back(components, v));
}
}
} /* !igraph_stack_empty(&path) */
}
} /* !igraph_stack_empty(&path) */
if (articulation_points && rootdfs >= 2) {
IGRAPH_CHECK(igraph_vector_push_back(articulation_points, i));
}
} /* i < no_of_nodes */
igraph_adjedgelist_destroy(&adjedgelist);
igraph_vector_destroy(&edgestack);
igraph_stack_destroy(&path);
igraph_vector_bool_destroy(&found);
igraph_vector_long_destroy(&low);
igraph_vector_long_destroy(&num);
igraph_vector_long_destroy(&nextptr);
IGRAPH_FINALLY_CLEAN(7);
return 0;
}
int main() {
igraph_vector_ptr_t v1, v2;
igraph_vector_ptr_t v3=IGRAPH_VECTOR_PTR_NULL;
int i;
void ** ptr;
int d1=1, d2=2, d3=3, d4=4, d5=5;
char *block1=0, *block2=0;
/* igraph_vector_ptr_init, igraph_vector_ptr_destroy */
igraph_vector_ptr_init(&v1, 10);
igraph_vector_ptr_destroy(&v1);
igraph_vector_ptr_init(&v1, 0);
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_free_all, igraph_vector_ptr_destroy_all */
igraph_vector_ptr_init(&v1, 5);
for (i=0; i<igraph_vector_ptr_size(&v1); i++) {
VECTOR(v1)[i]=(void*)malloc(i*10);
}
igraph_vector_ptr_free_all(&v1);
for (i=0; i<igraph_vector_ptr_size(&v1); i++) {
VECTOR(v1)[i]=(void*)malloc(i*10);
}
igraph_vector_ptr_destroy_all(&v1);
/* igraph_vector_ptr_reserve */
igraph_vector_ptr_init(&v1, 0);
igraph_vector_ptr_reserve(&v1, 5);
igraph_vector_ptr_reserve(&v1, 15);
igraph_vector_ptr_reserve(&v1, 1);
igraph_vector_ptr_reserve(&v1, 0);
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_empty, igraph_vector_ptr_clear */
igraph_vector_ptr_init(&v1, 10);
if (igraph_vector_ptr_empty(&v1)) {
return 1;
}
igraph_vector_ptr_clear(&v1);
if (!igraph_vector_ptr_empty(&v1)) {
return 2;
}
/* igraph_vector_ptr_size */
if (igraph_vector_ptr_size(&v1) != 0) {
return 3;
}
igraph_vector_ptr_resize(&v1, 10);
if (igraph_vector_ptr_size(&v1) != 10) {
return 4;
}
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_push_back */
igraph_vector_ptr_init(&v1, 0);
for (i=0; i<10; i++) {
igraph_vector_ptr_push_back(&v1, (void*)malloc(i*10));
}
igraph_vector_ptr_destroy_all(&v1);
/* igraph_vector_ptr_e */
igraph_vector_ptr_init(&v1, 5);
VECTOR(v1)[0]=&d1;
VECTOR(v1)[1]=&d2;
VECTOR(v1)[2]=&d3;
VECTOR(v1)[3]=&d4;
VECTOR(v1)[4]=&d5;
if (igraph_vector_ptr_e(&v1, 0) != &d1) {
return 5;
}
if (igraph_vector_ptr_e(&v1, 1) != &d2) {
return 6;
}
if (igraph_vector_ptr_e(&v1, 2) != &d3) {
return 7;
}
if (igraph_vector_ptr_e(&v1, 3) != &d4) {
return 8;
}
if (igraph_vector_ptr_e(&v1, 4) != &d5) {
return 9;
}
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_set */
igraph_vector_ptr_init(&v1, 5);
igraph_vector_ptr_set(&v1, 0, &d1);
igraph_vector_ptr_set(&v1, 1, &d2);
igraph_vector_ptr_set(&v1, 2, &d3);
igraph_vector_ptr_set(&v1, 3, &d4);
igraph_vector_ptr_set(&v1, 4, &d5);
if (igraph_vector_ptr_e(&v1, 0) != &d1) {
return 5;
}
if (igraph_vector_ptr_e(&v1, 1) != &d2) {
return 6;
}
if (igraph_vector_ptr_e(&v1, 2) != &d3) {
return 7;
}
if (igraph_vector_ptr_e(&v1, 3) != &d4) {
return 8;
}
if (igraph_vector_ptr_e(&v1, 4) != &d5) {
return 9;
}
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_null */
igraph_vector_ptr_init(&v1, 5);
igraph_vector_ptr_set(&v1, 0, &d1);
igraph_vector_ptr_set(&v1, 1, &d2);
igraph_vector_ptr_set(&v1, 2, &d3);
igraph_vector_ptr_set(&v1, 3, &d4);
igraph_vector_ptr_set(&v1, 4, &d5);
igraph_vector_ptr_null(&v1);
for (i=0; i<igraph_vector_ptr_size(&v1); i++) {
if (VECTOR(v1)[i] != 0) {
return 10;
}
}
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_resize */
igraph_vector_ptr_init(&v1, 10);
igraph_vector_ptr_set(&v1, 0, &d1);
igraph_vector_ptr_set(&v1, 1, &d2);
igraph_vector_ptr_set(&v1, 2, &d3);
igraph_vector_ptr_set(&v1, 3, &d4);
igraph_vector_ptr_set(&v1, 4, &d5);
igraph_vector_ptr_resize(&v1, 10);
igraph_vector_ptr_resize(&v1, 15);
igraph_vector_ptr_resize(&v1, 5);
if (igraph_vector_ptr_size(&v1) != 5) {
return 11;
}
if (igraph_vector_ptr_e(&v1, 0) != &d1) {
return 12;
}
if (igraph_vector_ptr_e(&v1, 1) != &d2) {
return 13;
}
if (igraph_vector_ptr_e(&v1, 2) != &d3) {
return 14;
}
if (igraph_vector_ptr_e(&v1, 3) != &d4) {
return 15;
}
if (igraph_vector_ptr_e(&v1, 4) != &d5) {
return 16;
}
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_view */
ptr=(void**) malloc(5 * sizeof(void*));
igraph_vector_ptr_view(&v3, ptr, 5);
ptr[0]=&d1; ptr[1]=&d2; ptr[2]=&d3; ptr[3]=&d4; ptr[4]=&d5;
for (i=0; i<igraph_vector_ptr_size(&v3); i++) {
if ( *((int*)VECTOR(v3)[i]) != i+1) {
return 17;
}
}
/* igraph_vector_ptr_init_copy */
igraph_vector_ptr_init_copy(&v1, ptr, 5);
for (i=0; i<igraph_vector_ptr_size(&v1); i++) {
if ( *((int*)VECTOR(v1)[i]) != i+1) {
return 18;
}
}
/* igraph_vector_ptr_copy_to */
igraph_vector_ptr_copy_to(&v1, ptr);
for (i=0; i<igraph_vector_ptr_size(&v1); i++) {
if ( *((int*)ptr[i]) != i+1) {
return 19;
}
}
free(ptr);
igraph_vector_ptr_destroy(&v1);
/* igraph_vector_ptr_copy */
igraph_vector_ptr_init(&v1, 5);
igraph_vector_ptr_set(&v1, 0, &d1);
igraph_vector_ptr_set(&v1, 1, &d2);
igraph_vector_ptr_set(&v1, 2, &d3);
igraph_vector_ptr_set(&v1, 3, &d4);
igraph_vector_ptr_set(&v1, 4, &d5);
igraph_vector_ptr_copy(&v2, &v1);
igraph_vector_ptr_destroy(&v1);
for (i=0; i<igraph_vector_ptr_size(&v2); i++) {
if ( *((int*)VECTOR(v2)[i]) != i+1) {
return 20;
}
}
/* igraph_vector_ptr_remove */
igraph_vector_ptr_remove(&v2, 0);
igraph_vector_ptr_remove(&v2, 3);
if ( *((int*)VECTOR(v2)[0]) != 2) {
return 21;
}
if ( *((int*)VECTOR(v2)[1]) != 3) {
return 22;
}
if ( *((int*)VECTOR(v2)[2]) != 4) {
return 23;
}
igraph_vector_ptr_destroy(&v2);
/* Testing destructor */
igraph_vector_ptr_init(&custom_destructor_stack, 0);
igraph_vector_ptr_init(&v1, 2);
block1 = igraph_Calloc(32, char);
block2 = igraph_Calloc(64, char);
VECTOR(v1)[0] = block1; VECTOR(v1)[1] = block2;
if (igraph_vector_ptr_get_item_destructor(&v1) != 0) {
return 24;
}
if (igraph_vector_ptr_set_item_destructor(&v1, &custom_destructor) != 0) {
return 25;
}
/* Okay, let's clear the vector. This should push the blocks in the
* custom destructor stack */
igraph_vector_ptr_clear(&v1);
/* Put the blocks back and destroy the vector */
igraph_vector_ptr_push_back(&v1, block1);
igraph_vector_ptr_push_back(&v1, block2);
igraph_vector_ptr_destroy_all(&v1);
if (VECTOR(custom_destructor_stack)[0] != block1 ||
VECTOR(custom_destructor_stack)[1] != block2 ||
VECTOR(custom_destructor_stack)[2] != block1 ||
VECTOR(custom_destructor_stack)[3] != block2
)
return 26;
igraph_vector_ptr_destroy(&custom_destructor_stack);
if (IGRAPH_FINALLY_STACK_SIZE() != 0) return 27;
return 0;
}
int igraph_all_minimal_st_separators(const igraph_t *graph,
igraph_vector_ptr_t *separators) {
/*
* Some notes about the tricks used here. For finding the components
* of the graph after removing some vertices, we do the
* following. First we mark the vertices with the actual mark stamp
* (mark), then run breadth-first search on the graph, but not
* considering the marked vertices. Then we increase the mark. If
* there is integer overflow here, then we zero out the mark and set
* it to one. (We might as well just always zero it out.)
*
* For each separator the vertices are stored in vertex id order.
* This facilitates the comparison of the separators when we find a
* potential new candidate.
*
* To keep track of which separator we already used as a basis, we
* keep a boolean vector (already_tried). The try_next pointer show
* the next separator to try as a basis.
*/
long int no_of_nodes=igraph_vcount(graph);
igraph_vector_t leaveout;
igraph_vector_bool_t already_tried;
long int try_next=0;
unsigned long int mark=1;
long int v;
igraph_adjlist_t adjlist;
igraph_vector_t components;
igraph_dqueue_t Q;
igraph_vector_t sorter;
igraph_vector_ptr_clear(separators);
IGRAPH_FINALLY(igraph_i_separators_free, separators);
IGRAPH_CHECK(igraph_vector_init(&leaveout, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_destroy, &leaveout);
IGRAPH_CHECK(igraph_vector_bool_init(&already_tried, 0));
IGRAPH_FINALLY(igraph_vector_bool_destroy, &already_tried);
IGRAPH_CHECK(igraph_vector_init(&components, 0));
IGRAPH_FINALLY(igraph_vector_destroy, &components);
IGRAPH_CHECK(igraph_vector_reserve(&components, no_of_nodes*2));
IGRAPH_CHECK(igraph_adjlist_init(graph, &adjlist, IGRAPH_ALL));
IGRAPH_FINALLY(igraph_adjlist_destroy, &adjlist);
IGRAPH_CHECK(igraph_dqueue_init(&Q, 100));
IGRAPH_FINALLY(igraph_dqueue_destroy, &Q);
IGRAPH_CHECK(igraph_vector_init(&sorter, 0));
IGRAPH_FINALLY(igraph_vector_destroy, &sorter);
IGRAPH_CHECK(igraph_vector_reserve(&sorter, no_of_nodes));
/* ---------------------------------------------------------------
* INITIALIZATION, we check whether the neighborhoods of the
* vertices separate the graph. The ones that do will form the
* initial basis.
*/
for (v=0; v<no_of_nodes; v++) {
/* Mark v and its neighbors */
igraph_vector_int_t *neis=igraph_adjlist_get(&adjlist, v);
long int i, n=igraph_vector_int_size(neis);
VECTOR(leaveout)[v]=mark;
for (i=0; i<n; i++) {
long int nei=(long int) VECTOR(*neis)[i];
VECTOR(leaveout)[nei]=mark;
}
/* Find the components */
IGRAPH_CHECK(igraph_i_clusters_leaveout(&adjlist, &components, &leaveout,
&mark, &Q));
/* Store the corresponding separators, N(C) for each component C */
IGRAPH_CHECK(igraph_i_separators_store(separators, &adjlist, &components,
&leaveout, &mark, &sorter));
}
/* ---------------------------------------------------------------
* GENERATION, we need to use all already found separators as
* basis and see if they generate more separators
*/
while (try_next < igraph_vector_ptr_size(separators)) {
igraph_vector_t *basis=VECTOR(*separators)[try_next];
long int b, basislen=igraph_vector_size(basis);
for (b=0; b<basislen; b++) {
/* Remove N(x) U basis */
long int x=(long int) VECTOR(*basis)[b];
igraph_vector_int_t *neis=igraph_adjlist_get(&adjlist, x);
long int i, n=igraph_vector_int_size(neis);
for (i=0; i<basislen; i++) {
long int sn=(long int) VECTOR(*basis)[i];
VECTOR(leaveout)[sn]=mark;
}
for (i=0; i<n; i++) {
long int nei=(long int) VECTOR(*neis)[i];
VECTOR(leaveout)[nei]=mark;
}
/* Find the components */
IGRAPH_CHECK(igraph_i_clusters_leaveout(&adjlist, &components,
&leaveout, &mark, &Q));
/* Store the corresponding separators, N(C) for each component C */
IGRAPH_CHECK(igraph_i_separators_store(separators, &adjlist,
&components, &leaveout, &mark,
&sorter));
}
try_next++;
}
/* --------------------------------------------------------------- */
igraph_vector_destroy(&sorter);
igraph_dqueue_destroy(&Q);
igraph_adjlist_destroy(&adjlist);
igraph_vector_destroy(&components);
igraph_vector_bool_destroy(&already_tried);
igraph_vector_destroy(&leaveout);
IGRAPH_FINALLY_CLEAN(7); /* +1 for separators */
return 0;
}
