flowtype Graph<captype,tcaptype,flowtype>::maxflow(bool reuse_trees, Block<node_id>* _changed_list) { node *i, *j, *current_node = NULL; arc *a; nodeptr *np, *np_next; if (!nodeptr_block) { nodeptr_block = new DBlock<nodeptr>(NODEPTR_BLOCK_SIZE, error_function); } changed_list = _changed_list; if (maxflow_iteration == 0 && reuse_trees) { if (error_function) (*error_function)("reuse_trees cannot be used in the first call to maxflow()!"); exit(1); } if (changed_list && !reuse_trees) { if (error_function) (*error_function)("changed_list cannot be used without reuse_trees!"); exit(1); } if (reuse_trees) maxflow_reuse_trees_init(); else maxflow_init(); // main loop while ( 1 ) { // test_consistency(current_node); if ((i=current_node)) { i -> next = NULL; /* remove active flag */ if (!i->parent) i = NULL; } if (!i) { if (!(i = next_active())) break; } /* growth */ if (!i->is_sink) { /* grow source tree */ for (a=i->first; a; a=a->next) if (a->r_cap) { j = a -> head; if (!j->parent) { j -> is_sink = 0; j -> parent = a -> sister; j -> TS = i -> TS; j -> DIST = i -> DIST + 1; set_active(j); add_to_changed_list(j); } else if (j->is_sink) break; else if (j->TS <= i->TS && j->DIST> i->DIST) { /* heuristic - trying to make the distance from j to the source shorter */ j -> parent = a -> sister; j -> TS = i -> TS; j -> DIST = i -> DIST + 1; } } } else { /* grow sink tree */ for (a=i->first; a; a=a->next) if (a->sister->r_cap) { j = a -> head; if (!j->parent) { j -> is_sink = 1; j -> parent = a -> sister; j -> TS = i -> TS; j -> DIST = i -> DIST + 1; set_active(j); add_to_changed_list(j); } else if (!j->is_sink) { a = a -> sister; break; } else if (j->TS <= i->TS && j->DIST> i->DIST) { /* heuristic - trying to make the distance from j to the sink shorter */ j -> parent = a -> sister; j -> TS = i -> TS; j -> DIST = i -> DIST + 1; } } } TIME ++; if (a) { i -> next = i; /* set active flag */ current_node = i; /* augmentation */ augment(a); /* augmentation end */ /* adoption */ while ((np=orphan_first)) { np_next = np -> next; np -> next = NULL; while ((np=orphan_first)) { orphan_first = np -> next; i = np -> ptr; nodeptr_block -> Delete(np); if (!orphan_first) orphan_last = NULL; if (i->is_sink) process_sink_orphan(i); else process_source_orphan(i); } orphan_first = np_next; } /* adoption end */ } else current_node = NULL; } // test_consistency(); if (!reuse_trees || (maxflow_iteration % 64) == 0) { delete nodeptr_block; nodeptr_block = NULL; } maxflow_iteration ++; return flow; }
void Graph<captype,tcaptype,flowtype>::maxflow_reuse_trees_init() { node* i; node* j; node* queue = queue_first[1]; arc* a; nodeptr* np; queue_first[0] = queue_last[0] = NULL; queue_first[1] = queue_last[1] = NULL; orphan_first = orphan_last = NULL; TIME ++; while ((i=queue)) { queue = i->next; if (queue == i) queue = NULL; i->next = NULL; i->is_marked = 0; set_active(i); if (i->tr_cap == 0) { if (i->parent) set_orphan_rear(i); continue; } if (i->tr_cap> 0) { if (!i->parent || i->is_sink) { i->is_sink = 0; for (a=i->first; a; a=a->next) { j = a->head; if (!j->is_marked) { if (j->parent == a->sister) set_orphan_rear(j); if (j->parent && j->is_sink && a->r_cap> 0) set_active(j); } } add_to_changed_list(i); } } else { if (!i->parent || !i->is_sink) { i->is_sink = 1; for (a=i->first; a; a=a->next) { j = a->head; if (!j->is_marked) { if (j->parent == a->sister) set_orphan_rear(j); if (j->parent && !j->is_sink && a->sister->r_cap> 0) set_active(j); } } add_to_changed_list(i); } } i->parent = TERMINAL; i -> TS = TIME; i -> DIST = 1; } //test_consistency(); /* adoption */ while ((np=orphan_first)) { orphan_first = np -> next; i = np -> ptr; nodeptr_block -> Delete(np); if (!orphan_first) orphan_last = NULL; if (i->is_sink) process_sink_orphan(i); else process_source_orphan(i); } /* adoption end */ //test_consistency(); }
void Graph<captype,tcaptype,flowtype>::process_sink_orphan(node *i) { node *j; arc *a0, *a0_min = NULL, *a; int d, d_min = INFINITE_D; /* trying to find a new parent */ for (a0=i->first; a0; a0=a0->next) if (a0->r_cap) { j = a0 -> head; if (j->is_sink && (a=j->parent)) { /* checking the origin of j */ d = 0; while ( 1 ) { if (j->TS == TIME) { d += j -> DIST; break; } a = j -> parent; d ++; if (a==TERMINAL) { j -> TS = TIME; j -> DIST = 1; break; } if (a==ORPHAN) { d = INFINITE_D; break; } j = a -> head; } if (d<INFINITE_D) /* j originates from the sink - done */ { if (d<d_min) { a0_min = a0; d_min = d; } /* set marks along the path */ for (j=a0->head; j->TS!=TIME; j=j->parent->head) { j -> TS = TIME; j -> DIST = d --; } } } } if (i->parent = a0_min) { i -> TS = TIME; i -> DIST = d_min + 1; } else { /* no parent is found */ add_to_changed_list(i); /* process neighbors */ for (a0=i->first; a0; a0=a0->next) { j = a0 -> head; if (j->is_sink && (a=j->parent)) { if (a0->r_cap) set_active(j); if (a!=TERMINAL && a!=ORPHAN && a->head==i) { set_orphan_rear(j); // add j to the end of the adoption list } } } } }
void QPBO<REAL>::maxflow_reuse_trees_init() { Node* i; Node* j; Node* queue = queue_first[1]; Arc* a; nodeptr* np; queue_first[0] = queue_last[0] = NULL; queue_first[1] = queue_last[1] = NULL; orphan_first = orphan_last = NULL; TIME ++; while ((i=queue)) { queue = i->next; if (queue == i) queue = NULL; if (IsNode0(i)) { if (i->is_removed) continue; } else { if (GetMate1(i)->is_removed) continue; } i->next = NULL; i->is_marked = 0; set_active(i); if (i->tr_cap == 0) { if (i->parent) set_orphan_rear(i); continue; } if (i->tr_cap > 0) { if (!i->parent || i->is_sink) { i->is_sink = 0; for (a=i->first; a; a=a->next) { j = a->head; if (!j->is_marked) { if (j->parent == a->sister) set_orphan_rear(j); if (j->parent && j->is_sink && a->r_cap > 0) set_active(j); } } add_to_changed_list(i); } } else { if (!i->parent || !i->is_sink) { i->is_sink = 1; for (a=i->first; a; a=a->next) { j = a->head; if (!j->is_marked) { if (j->parent == a->sister) set_orphan_rear(j); if (j->parent && !j->is_sink && a->sister->r_cap > 0) set_active(j); } } add_to_changed_list(i); } } i->parent = QPBO_MAXFLOW_TERMINAL; i -> TS = TIME; i -> DIST = 1; } code_assert(stage == 1); //test_consistency(); /* adoption */ while ((np=orphan_first)) { orphan_first = np -> next; i = np -> ptr; nodeptr_block -> Delete(np); if (!orphan_first) orphan_last = NULL; if (i->is_sink) process_sink_orphan(i); else process_source_orphan(i); } /* adoption end */ //test_consistency(); }