_sink = &_vertices[sink];
for(int e = 0; e < nb_edges; e++) {
- _vertices[vertex_from[e]].add_leaving_edge(_edges + e);
+ _vertices[vertex_from[e]].add_leaving_edge(&_edges[e]);
_edges[e].occupied = 0;
- _edges[e].origin_vertex = _vertices + vertex_from[e];
- _edges[e].terminal_vertex = _vertices + vertex_to[e];
+ _edges[e].origin_vertex = &_vertices[vertex_from[e]];
+ _edges[e].terminal_vertex = &_vertices[vertex_to[e]];
}
for(int v = 0; v < _nb_vertices; v++) {
paths = 0;
nb_paths = 0;
- compute_dp_ranks();
- for(int v = 0; v < _nb_vertices; v++) { _dp_order[v] = &_vertices[v]; }
- qsort(_dp_order, _nb_vertices, sizeof(Vertex *), compare_vertices_on_distance);
+ compute_dp_ordering();
}
MTPGraph::~MTPGraph() {
//////////////////////////////////////////////////////////////////////
-void MTPGraph::compute_dp_ranks() {
- Vertex *v;
- Edge *e;
- int tv;
-
- // This procedure computes for each node the longest link from the
- // source and abort if the graph is not a DAG. It works by removing
- // successively nodes without predecessor: At the first iteration it
- // removes the source, then the nodes with incoming edge only from
- // the source, etc. If it can remove all the nodes that way, the
- // graph is a DAG. If at some point it can not remove node anymore
- // and there are some remaining nodes, the graph is not a DAG. The
- // rank of a node is the iteration at which is it removed, and we
- // set the distance_from_source fields to this value.
-
- int *nb_predecessors = new int[_nb_vertices];
- int *without_predecessor = new int[_nb_vertices];
- int *new_without_predecessor = new int[_nb_vertices];
- int nb_without_predecessor, new_nb_without_predecessor;
-
- for(int k = 0; k < _nb_vertices; k++) {
- nb_predecessors[k] = 0;
- }
-
- for(int k = 0; k < _nb_vertices; k++) {
- v = _vertices + k;
- for(e = v->leaving_edge_list_root; e; e = e->next_leaving_edge) {
- tv = int(e->terminal_vertex - _vertices);
- nb_predecessors[tv]++;
- }
- }
-
- nb_without_predecessor = 0;
- for(int k = 0; k < _nb_vertices; k++) {
- if(nb_predecessors[k] == 0) {
- without_predecessor[nb_without_predecessor++] = k;
- }
- }
-
- scalar_t rank = 1;
- while(nb_without_predecessor > 0) {
- new_nb_without_predecessor = 0;
- for(int l = 0; l < nb_without_predecessor; l++) {
- v = _vertices + without_predecessor[l];
- v->distance_from_source = rank;
- for(e = v->leaving_edge_list_root; e; e = e->next_leaving_edge) {
- tv = int(e->terminal_vertex - _vertices);
- nb_predecessors[tv]--;
- ASSERT(nb_predecessors[tv] >= 0);
- if(nb_predecessors[tv] == 0) {
- new_without_predecessor[new_nb_without_predecessor++] = tv;
- }
- }
- }
-
- swap(without_predecessor, new_without_predecessor);
- nb_without_predecessor = new_nb_without_predecessor;
- rank++;
- }
-
- for(int k = 0; k < _nb_vertices; k++) {
- if(nb_predecessors[k] > 0) {
- cerr << __FILE__ << ": The graph is not a DAG." << endl;
- abort();
- }
- }
-
- delete[] nb_predecessors;
- delete[] without_predecessor;
- delete[] new_without_predecessor;
-}
-
-//////////////////////////////////////////////////////////////////////
-
void MTPGraph::print(ostream *os) {
for(int k = 0; k < _nb_edges; k++) {
- Edge *e = _edges + k;
+ Edge *e = &_edges[k];
(*os) << e->origin_vertex - _vertices
<< " -> "
<< e->terminal_vertex - _vertices
(*os) << " " << _source - _vertices << " [peripheries=2];" << endl;
(*os) << " " << _sink - _vertices << " [peripheries=2];" << endl;
for(int k = 0; k < _nb_edges; k++) {
- Edge *e = _edges + k;
+ Edge *e = &_edges[k];
(*os) << " "
<< e->origin_vertex - _vertices
<< " -> "
void MTPGraph::update_positivized_lengths() {
for(int k = 0; k < _nb_edges; k++) {
- Edge *e = _edges + k;
+ Edge *e = &_edges[k];
e->positivized_length +=
e->origin_vertex->distance_from_source - e->terminal_vertex->distance_from_source;
}
scalar_t max_error = 0.0;
#endif
for(int k = 0; k < _nb_edges; k++) {
- Edge *e = _edges + k;
+ Edge *e = &_edges[k];
if(e->positivized_length < 0) {
#ifdef VERBOSE
// Put back the graph in its original state (i.e. invert edges which
// have been inverted in the process)
for(int k = 0; k < _nb_edges; k++) {
- e = _edges + k;
+ e = &_edges[k];
if(e->occupied) { e->invert(); }
}
}
return l;
}
+//////////////////////////////////////////////////////////////////////
+
+void MTPGraph::compute_dp_ordering() {
+ Vertex *v;
+ Edge *e;
+ int tv;
+
+ // This procedure computes for each node the longest link from the
+ // source, and abort if the graph is not a DAG, and order the node
+ // in _dp_order according to that value.
+
+ int *nb_predecessors = new int[_nb_vertices];
+
+ Vertex **already_processed = _dp_order, **front = _dp_order, **new_front = _dp_order;
+
+ for(int k = 0; k < _nb_vertices; k++) {
+ nb_predecessors[k] = 0;
+ }
+
+ for(int k = 0; k < _nb_vertices; k++) {
+ v = &_vertices[k];
+ for(e = v->leaving_edge_list_root; e; e = e->next_leaving_edge) {
+ tv = int(e->terminal_vertex - _vertices);
+ nb_predecessors[tv]++;
+ }
+ }
+
+ for(int k = 0; k < _nb_vertices; k++) {
+ if(nb_predecessors[k] == 0) {
+ *(front++) = _vertices + k;
+ }
+ }
+
+ scalar_t rank = 1;
+ while(already_processed < front) {
+ new_front = front;
+ while(already_processed < front) {
+ v = *(already_processed++);
+ v->distance_from_source = rank;
+ for(e = v->leaving_edge_list_root; e; e = e->next_leaving_edge) {
+ tv = int(e->terminal_vertex - _vertices);
+ nb_predecessors[tv]--;
+ ASSERT(nb_predecessors[tv] >= 0);
+ if(nb_predecessors[tv] == 0) {
+ *(new_front++) = e->terminal_vertex;
+ }
+ }
+ }
+ front = new_front;
+ rank++;
+ }
+
+ if(already_processed < _dp_order + _nb_vertices) {
+ cerr << __FILE__ << ": The graph is not a DAG." << endl;
+ abort();
+ }
+
+ delete[] nb_predecessors;
+
+ for(int v = 0; v < _nb_vertices; v++) { _dp_order[v] = &_vertices[v]; }
+ qsort(_dp_order, _nb_vertices, sizeof(Vertex *), compare_vertices_on_distance);
+}
+
+//////////////////////////////////////////////////////////////////////
+
void MTPGraph::retrieve_disjoint_paths() {
Edge *e;
int p, l;