/* #include "igraph_visitor.h"
#include "igraph_memory.h"
#include "igraph_adjlist.h"
#include "igraph_interface.h"
#include "igraph_dqueue.h"
#include "igraph_stack.h"
#include "config.h"*/
int igraph_bfsr(const igraph_t *graph,
igraph_integer_t root,igraph_vector_t *roots,
igraph_neimode_t mode, igraph_bool_t unreachable,
const igraph_vector_t *restricted,
igraph_vector_t *order, igraph_vector_t *rank,
igraph_vector_t *father,
igraph_vector_t *pred, igraph_vector_t *succ,
igraph_vector_t *dist, igraph_bfshandler_t *callback,
void *extra) {
igraph_dqueue_t Q;
long int no_of_nodes=igraph_vcount(graph);
long int actroot=0;
igraph_vector_char_t added;
igraph_lazy_adjlist_t adjlist;
long int act_rank=0;
long int pred_vec=-1;
long int rootpos=0;
long int noroots= roots ? igraph_vector_size(roots) : 1;
if (!roots && (root < 0 || root >= no_of_nodes)) {
IGRAPH_ERROR("Invalid root vertex in BFS", IGRAPH_EINVAL);
}
if (roots) {
igraph_real_t min, max;
igraph_vector_minmax(roots, &min, &max);
if (min < 0 || max >= no_of_nodes) {
IGRAPH_ERROR("Invalid root vertex in BFS", IGRAPH_EINVAL);
}
}
if (restricted) {
igraph_real_t min, max;
igraph_vector_minmax(restricted, &min, &max);
if (min < 0 || max >= no_of_nodes) {
IGRAPH_ERROR("Invalid vertex id in restricted set", IGRAPH_EINVAL);
}
}
if (mode != IGRAPH_OUT && mode != IGRAPH_IN &&
mode != IGRAPH_ALL) {
IGRAPH_ERROR("Invalid mode argument", IGRAPH_EINVMODE);
}
if (!igraph_is_directed(graph)) { mode=IGRAPH_ALL; }
IGRAPH_CHECK(igraph_vector_char_init(&added, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_char_destroy, &added);
IGRAPH_CHECK(igraph_dqueue_init(&Q, 100));
IGRAPH_FINALLY(igraph_dqueue_destroy, &Q);
IGRAPH_CHECK(igraph_lazy_adjlist_init(graph, &adjlist, mode, /*simplify=*/ 0));
IGRAPH_FINALLY(igraph_lazy_adjlist_destroy, &adjlist);
/* Mark the vertices that are not in the restricted set, as already
found. Special care must be taken for vertices that are not in
the restricted set, but are to be used as 'root' vertices. */
if (restricted) {
long int i, n=igraph_vector_size(restricted);
igraph_vector_char_fill(&added, 1);
for (i=0; i<n; i++) {
long int v=(long int) VECTOR(*restricted)[i];
VECTOR(added)[v]=0;
}
}
/* Resize result vectors, and fill them with IGRAPH_NAN */
# define VINIT(v) if (v) { \
igraph_vector_resize((v), no_of_nodes); \
igraph_vector_fill((v), IGRAPH_NAN); }
VINIT(order);
VINIT(rank);
VINIT(father);
VINIT(pred);
VINIT(succ);
VINIT(dist);
# undef VINIT
while (1) {
/* Get the next root vertex, if any */
if (roots && rootpos < noroots) {
/* We are still going through the 'roots' vector */
actroot=(long int) VECTOR(*roots)[rootpos++];
} else if (!roots && rootpos==0) {
/* We have a single root vertex given, and start now */
actroot=root;
rootpos++;
} else if (rootpos==noroots && unreachable) {
/* We finished the given root(s), but other vertices are also
tried as root */
actroot=0;
rootpos++;
} else if (unreachable && actroot+1 < no_of_nodes) {
/* We are already doing the other vertices, take the next one */
actroot++;
} else {
/* No more root nodes to do */
break;
}
/* OK, we have a new root, start BFS */
if (VECTOR(added)[actroot]) { continue; }
IGRAPH_CHECK(igraph_dqueue_push(&Q, actroot));
IGRAPH_CHECK(igraph_dqueue_push(&Q, 0));
VECTOR(added)[actroot] = 1;
if (father) { VECTOR(*father)[actroot] = -1; }
pred_vec=-1;
while (!igraph_dqueue_empty(&Q)) {
long int actvect=(long int) igraph_dqueue_pop(&Q);
long int actdist=(long int) igraph_dqueue_pop(&Q);
long int succ_vec;
igraph_vector_t *neis=igraph_lazy_adjlist_get(&adjlist,
(igraph_integer_t) actvect);
long int i, n=igraph_vector_size(neis);
if (pred) { VECTOR(*pred)[actvect] = pred_vec; }
if (rank) { VECTOR(*rank) [actvect] = act_rank; }
if (order) { VECTOR(*order)[act_rank++] = actvect; }
if (dist) { VECTOR(*dist)[actvect] = actdist; }
igraph_vector_shuffle(neis);
for (i=0; i<n; i++) {
long int nei=(long int) VECTOR(*neis)[i];
if (! VECTOR(added)[nei]) {
VECTOR(added)[nei] = 1;
IGRAPH_CHECK(igraph_dqueue_push(&Q, nei));
IGRAPH_CHECK(igraph_dqueue_push(&Q, actdist+1));
if (father) { VECTOR(*father)[nei] = actvect; }
}
}
succ_vec = igraph_dqueue_empty(&Q) ? -1L :
(long int) igraph_dqueue_head(&Q);
if (callback) {
igraph_bool_t terminate=
callback(graph, (igraph_integer_t) actvect, (igraph_integer_t)
pred_vec, (igraph_integer_t) succ_vec,
(igraph_integer_t) act_rank-1, (igraph_integer_t) actdist,
extra);
if (terminate) {
igraph_lazy_adjlist_destroy(&adjlist);
igraph_dqueue_destroy(&Q);
igraph_vector_char_destroy(&added);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
}
if (succ) { VECTOR(*succ)[actvect] = succ_vec; }
pred_vec=actvect;
} /* while Q !empty */
} /* for actroot < no_of_nodes */
igraph_lazy_adjlist_destroy(&adjlist);
igraph_dqueue_destroy(&Q);
igraph_vector_char_destroy(&added);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
int dfs_d(const igraph_t *graph, igraph_integer_t root,
igraph_neimode_t mode, igraph_bool_t unreachable,
igraph_vector_t *order,
igraph_vector_t *order_out, igraph_vector_t *father,
igraph_vector_t *dist, igraph_dfshandler_t *in_callback,
igraph_dfshandler_t *out_callback,
void *extra) {
long int no_of_nodes=igraph_vcount(graph);
igraph_lazy_adjlist_t adjlist;
igraph_stack_t stack;
igraph_vector_char_t added;
igraph_vector_long_t nptr;
long int actroot;
long int act_rank=0;
long int rank_out=0;
long int act_dist=0;
if (root < 0 || root >= no_of_nodes) {
IGRAPH_ERROR("Invalid root vertex for DFS", IGRAPH_EINVAL);
}
if (mode != IGRAPH_OUT && mode != IGRAPH_IN &&
mode != IGRAPH_ALL) {
IGRAPH_ERROR("Invalid mode argument", IGRAPH_EINVMODE);
}
if (!igraph_is_directed(graph)) { mode=IGRAPH_ALL; }
IGRAPH_CHECK(igraph_vector_char_init(&added, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_char_destroy, &added);
IGRAPH_CHECK(igraph_stack_init(&stack, 100));
IGRAPH_FINALLY(igraph_stack_destroy, &stack);
IGRAPH_CHECK(igraph_lazy_adjlist_init(graph, &adjlist, mode, /*simplify=*/ 0));
IGRAPH_FINALLY(igraph_lazy_adjlist_destroy, &adjlist);
IGRAPH_CHECK(igraph_vector_long_init(&nptr, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &nptr);
# define FREE_ALL() do { \
igraph_vector_long_destroy(&nptr); \
igraph_lazy_adjlist_destroy(&adjlist); \
igraph_stack_destroy(&stack); \
igraph_vector_char_destroy(&added); \
IGRAPH_FINALLY_CLEAN(4); } while (0)
/* Resize result vectors and fill them with IGRAPH_NAN */
# define VINIT(v) if (v) { \
igraph_vector_resize(v, no_of_nodes); \
igraph_vector_fill(v, IGRAPH_NAN); }
VINIT(order);
VINIT(order_out);
VINIT(father);
VINIT(dist);
# undef VINIT
IGRAPH_CHECK(igraph_stack_push(&stack, root));
VECTOR(added)[(long int)root] = 1;
if (father) { VECTOR(*father)[(long int)root] = -1; }
if (order) { VECTOR(*order)[act_rank++] = root; }
if (dist) { VECTOR(*dist)[(long int)root] = 0; }
if (in_callback) {
igraph_bool_t terminate=in_callback(graph, root, 0, extra);
if (terminate) { FREE_ALL(); return 0; }
}
for (actroot=0; actroot<no_of_nodes; actroot++) {
/* 'root' first, then all other vertices */
if (igraph_stack_empty(&stack)) {
if (!unreachable) { break; }
if (VECTOR(added)[actroot]) { continue; }
IGRAPH_CHECK(igraph_stack_push(&stack, actroot));
VECTOR(added)[actroot] = 1;
if (father) { VECTOR(*father)[actroot] = -1; }
if (order) { VECTOR(*order)[act_rank++] = actroot; }
if (dist) { VECTOR(*dist)[actroot] = 0; }
if (in_callback) {
igraph_bool_t terminate=in_callback(graph, (igraph_integer_t) actroot,
0, extra);
if (terminate) { FREE_ALL(); return 0; }
}
}
while (!igraph_stack_empty(&stack)) {
long int actvect=(long int) igraph_stack_top(&stack);
igraph_vector_t *neis=igraph_lazy_adjlist_get(&adjlist,
(igraph_integer_t) actvect);
long int n=igraph_vector_size(neis);
long int *ptr=igraph_vector_long_e_ptr(&nptr, actvect);
igraph_vector_shuffle(neis);
igraph_vector_print(neis);
/* Search for a neighbor that was not yet visited */
igraph_bool_t any=0;
long int nei;
while (!any && (*ptr) <n) {
nei=(long int) VECTOR(*neis)[(*ptr)];
any=!VECTOR(added)[nei];
(*ptr) ++;
}
if (any) {
/* There is such a neighbor, add it */
IGRAPH_CHECK(igraph_stack_push(&stack, nei));
VECTOR(added)[nei] = 1;
if (father) { VECTOR(*father)[ nei ] = actvect; }
if (order) { VECTOR(*order)[act_rank++] = nei; }
act_dist++;
if (dist) { VECTOR(*dist)[nei] = act_dist; }
if (in_callback) {
igraph_bool_t terminate=in_callback(graph, (igraph_integer_t) nei,
(igraph_integer_t) act_dist,
extra);
if (terminate) { FREE_ALL(); return 0; }
}
} else {
/* There is no such neighbor, finished with the subtree */
igraph_stack_pop(&stack);
if (order_out) { VECTOR(*order_out)[rank_out++] = actvect; }
act_dist--;
if (out_callback) {
igraph_bool_t terminate=out_callback(graph, (igraph_integer_t)
actvect, (igraph_integer_t)
act_dist, extra);
if (terminate) { FREE_ALL(); return 0; }
}
}
}
}
FREE_ALL();
# undef FREE_ALL
return 0;
}
int main() {
igraph_real_t d;
igraph_vector_t u, v;
int ret;
long int i, k, n;
/********************************
* Example usage
********************************/
/* Sequences with one element. Such sequences are trivially permuted.
* The result of any Fisher-Yates shuffle on a sequence with one element
* must be the original sequence itself.
*/
n = 1;
igraph_vector_init(&v, n);
igraph_rng_seed(igraph_rng_default(), time(0));
k = R_INTEGER(-1000, 1000);
VECTOR(v)[0] = k;
igraph_vector_shuffle(&v);
if (VECTOR(v)[0] != k) {
return 1;
}
d = R_UNIF(-1000.0, 1000.0);
VECTOR(v)[0] = d;
igraph_vector_shuffle(&v);
if (VECTOR(v)[0] != d) {
return 2;
}
igraph_vector_destroy(&v);
/* Sequences with multiple elements. A Fisher-Yates shuffle of a sequence S
* is a random permutation \pi(S) of S. Thus \pi(S) must have the same
* length and elements as the original sequence S. A major difference between
* S and its random permutation \pi(S) is that the order in which elements
* appear in \pi(S) is probably different from how elements are ordered in S.
* If S has length n = 1, then both \pi(S) and S are equivalent sequences in
* that \pi(S) is merely S and no permutation has taken place. If S has
* length n > 1, then there are n! possible permutations of S. Assume that
* each such permutation is equally likely to appear as a result of the
* Fisher-Yates shuffle. As n increases, the probability that S is different
* from \pi(S) also increases. We have a probability of 1 / n! that S and
* \pi(S) are equivalent sequences.
*/
n = 100;
igraph_vector_init(&u, n);
igraph_vector_init(&v, n);
for (i = 0; i < n; i++) {
k = R_INTEGER(-1000, 1000);
VECTOR(u)[i] = k;
VECTOR(v)[i] = k;
}
igraph_vector_shuffle(&v);
/* must have same length */
if (igraph_vector_size(&v) != n) {
return 3;
}
if (igraph_vector_size(&u) != igraph_vector_size(&v)) {
return 4;
}
/* must have same elements */
igraph_vector_sort(&u);
igraph_vector_sort(&v);
if (!igraph_vector_all_e(&u, &v)) {
return 5;
}
igraph_vector_destroy(&u);
igraph_vector_destroy(&v);
/* empty sequence */
igraph_vector_init(&v, 0);
ret = igraph_vector_shuffle(&v);
igraph_vector_destroy(&v);
return ret == 0 ? 0 : 6;
}
