2 * src/lemon/list_graph.h - Part of LEMON, a generic C++ optimization library
4 * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Combinatorial Optimization Research Group, EGRES).
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
17 #ifndef LEMON_LIST_GRAPH_H
18 #define LEMON_LIST_GRAPH_H
22 ///\brief ListGraph, SymListGraph, NodeSet and EdgeSet classes.
24 #include <lemon/erasable_graph_extender.h>
25 #include <lemon/clearable_graph_extender.h>
26 #include <lemon/extendable_graph_extender.h>
27 #include <lemon/iterable_graph_extender.h>
28 #include <lemon/alteration_notifier.h>
29 #include <lemon/default_map.h>
31 #include <lemon/undir_graph_extender.h>
41 int first_in,first_out;
47 int prev_in, prev_out;
48 int next_in, next_out;
51 std::vector<NodeT> nodes;
57 std::vector<EdgeT> edges;
63 typedef ListGraphBase Graph;
66 friend class ListGraphBase;
70 Node(int pid) { id = pid;}
74 Node (Invalid) { id = -1; }
75 bool operator==(const Node& node) const {return id == node.id;}
76 bool operator!=(const Node& node) const {return id != node.id;}
77 bool operator<(const Node& node) const {return id < node.id;}
81 friend class ListGraphBase;
85 Edge(int pid) { id = pid;}
89 Edge (Invalid) { id = -1; }
90 bool operator==(const Edge& edge) const {return id == edge.id;}
91 bool operator!=(const Edge& edge) const {return id != edge.id;}
92 bool operator<(const Edge& edge) const {return id < edge.id;}
98 : nodes(), first_node(-1),
99 first_free_node(-1), edges(), first_free_edge(-1) {}
106 int maxId(Node = INVALID) const { return nodes.size()-1; }
112 int maxId(Edge = INVALID) const { return edges.size()-1; }
114 Node source(Edge e) const { return edges[e.id].source; }
115 Node target(Edge e) const { return edges[e.id].target; }
118 void first(Node& node) const {
119 node.id = first_node;
122 void next(Node& node) const {
123 node.id = nodes[node.id].next;
127 void first(Edge& e) const {
130 n!=-1 && nodes[n].first_in == -1;
132 e.id = (n == -1) ? -1 : nodes[n].first_in;
135 void next(Edge& edge) const {
136 if (edges[edge.id].next_in != -1) {
137 edge.id = edges[edge.id].next_in;
140 for(n = nodes[edges[edge.id].target].next;
141 n!=-1 && nodes[n].first_in == -1;
143 edge.id = (n == -1) ? -1 : nodes[n].first_in;
147 void firstOut(Edge &e, const Node& v) const {
148 e.id = nodes[v.id].first_out;
150 void nextOut(Edge &e) const {
151 e.id=edges[e.id].next_out;
154 void firstIn(Edge &e, const Node& v) const {
155 e.id = nodes[v.id].first_in;
157 void nextIn(Edge &e) const {
158 e.id=edges[e.id].next_in;
162 static int id(Node v) { return v.id; }
163 static int id(Edge e) { return e.id; }
165 /// Adds a new node to the graph.
167 /// \warning It adds the new node to the front of the list.
168 /// (i.e. the lastly added node becomes the first.)
172 if(first_free_node==-1) {
174 nodes.push_back(NodeT());
177 first_free_node = nodes[n].next;
180 nodes[n].next = first_node;
181 if(first_node != -1) nodes[first_node].prev = n;
185 nodes[n].first_in = nodes[n].first_out = -1;
190 Edge addEdge(Node u, Node v) {
193 if (first_free_edge == -1) {
195 edges.push_back(EdgeT());
198 first_free_edge = edges[n].next_in;
201 edges[n].source = u.id;
202 edges[n].target = v.id;
204 edges[n].next_out = nodes[u.id].first_out;
205 if(nodes[u.id].first_out != -1) {
206 edges[nodes[u.id].first_out].prev_out = n;
209 edges[n].next_in = nodes[v.id].first_in;
210 if(nodes[v.id].first_in != -1) {
211 edges[nodes[v.id].first_in].prev_in = n;
214 edges[n].prev_in = edges[n].prev_out = -1;
216 nodes[u.id].first_out = nodes[v.id].first_in = n;
221 void erase(const Node& node) {
224 if(nodes[n].next != -1) {
225 nodes[nodes[n].next].prev = nodes[n].prev;
228 if(nodes[n].prev != -1) {
229 nodes[nodes[n].prev].next = nodes[n].next;
231 first_node = nodes[n].next;
234 nodes[n].next = first_free_node;
239 void erase(const Edge& edge) {
242 if(edges[n].next_in!=-1) {
243 edges[edges[n].next_in].prev_in = edges[n].prev_in;
246 if(edges[n].prev_in!=-1) {
247 edges[edges[n].prev_in].next_in = edges[n].next_in;
249 nodes[edges[n].target].first_in = edges[n].next_in;
253 if(edges[n].next_out!=-1) {
254 edges[edges[n].next_out].prev_out = edges[n].prev_out;
257 if(edges[n].prev_out!=-1) {
258 edges[edges[n].prev_out].next_out = edges[n].next_out;
260 nodes[edges[n].source].first_out = edges[n].next_out;
263 edges[n].next_in = first_free_edge;
271 first_node = first_free_node = first_free_edge = -1;
275 void _moveTarget(Edge e, Node n)
277 if(edges[e.id].next_in != -1)
278 edges[edges[e.id].next_in].prev_in = edges[e.id].prev_in;
279 if(edges[e.id].prev_in != -1)
280 edges[edges[e.id].prev_in].next_in = edges[e.id].next_in;
281 else nodes[edges[e.id].target].first_in = edges[e.id].next_in;
282 edges[e.id].target = n.id;
283 edges[e.id].prev_in = -1;
284 edges[e.id].next_in = nodes[n.id].first_in;
285 nodes[n.id].first_in = e.id;
287 void _moveSource(Edge e, Node n)
289 if(edges[e.id].next_out != -1)
290 edges[edges[e.id].next_out].prev_out = edges[e.id].prev_out;
291 if(edges[e.id].prev_out != -1)
292 edges[edges[e.id].prev_out].next_out = edges[e.id].next_out;
293 else nodes[edges[e.id].source].first_out = edges[e.id].next_out;
294 edges[e.id].source = n.id;
295 edges[e.id].prev_out = -1;
296 edges[e.id].next_out = nodes[n.id].first_out;
297 nodes[n.id].first_out = e.id;
302 typedef AlterableGraphExtender<ListGraphBase> AlterableListGraphBase;
303 typedef IterableGraphExtender<AlterableListGraphBase> IterableListGraphBase;
304 typedef DefaultMappableGraphExtender<IterableListGraphBase> MappableListGraphBase;
305 typedef ExtendableGraphExtender<MappableListGraphBase> ExtendableListGraphBase;
306 typedef ClearableGraphExtender<ExtendableListGraphBase> ClearableListGraphBase;
307 typedef ErasableGraphExtender<ClearableListGraphBase> ErasableListGraphBase;
309 /// \addtogroup graphs
312 ///A list graph class.
314 ///This is a simple and fast erasable graph implementation.
316 ///It addition that it conforms to the
317 ///\ref concept::ErasableGraph "ErasableGraph" concept,
318 ///it also provides several additional useful extra functionalities.
319 ///\sa concept::ErasableGraph.
321 class ListGraph : public ErasableListGraphBase
324 /// Moves the target of \c e to \c n
326 /// Moves the target of \c e to \c n
328 ///\note The <tt>Edge</tt>'s and <tt>OutEdge</tt>'s
329 ///referencing the moved edge remain
330 ///valid. However <tt>InEdge</tt>'s are invalidated.
331 void moveTarget(Edge e, Node n) { _moveTarget(e,n); }
332 /// Moves the source of \c e to \c n
334 /// Moves the source of \c e to \c n
336 ///\note The <tt>Edge</tt>'s and <tt>InEdge</tt>'s
337 ///referencing the moved edge remain
338 ///valid. However <tt>OutEdge</tt>'s are invalidated.
339 void moveSource(Edge e, Node n) { _moveSource(e,n); }
341 /// Invert the direction of an edge.
343 ///\note The <tt>Edge</tt>'s
344 ///referencing the moved edge remain
345 ///valid. However <tt>OutEdge</tt>'s and <tt>InEdge</tt>'s are invalidated.
346 void reverseEdge(Edge e) {
348 _moveTarget(e,source(e));
352 ///Using this it possible to avoid the superfluous memory allocation.
354 ///Using this it possible to avoid the superfluous memory allocation.
355 ///\todo more docs...
356 void reserveEdge(int n) { edges.reserve(n); };
358 ///Contract two nodes.
360 ///This function contracts two nodes.
362 ///Node \p b will be removed but instead of deleting
363 ///its neighboring edges, they will be joined to \p a.
364 ///The last parameter \p r controls whether to remove loops. \c true
365 ///means that loops will be removed.
367 ///\note The <tt>Edge</tt>s
368 ///referencing the moved edge remain
369 ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
370 ///may be invalidated.
371 void contract(Node a,Node b,bool r=true)
373 for(OutEdgeIt e(*this,b);e!=INVALID;) {
376 if(r && target(e)==a) erase(e);
377 else moveSource(e,b);
380 for(InEdgeIt e(*this,b);e!=INVALID;) {
383 if(r && source(e)==a) erase(e);
384 else moveTarget(e,b);
391 ///Class to make a snapshot of the graph and to restrore to it later.
393 ///Class to make a snapshot of the graph and to restrore to it later.
395 ///The newly added nodes and edges can be removed using the
396 ///restore() function.
398 ///\warning Edge and node deletions cannot be restored.
399 ///\warning SnapShots cannot be nested.
401 ///\todo \c SnapShot or \c Snapshot?
402 class SnapShot : protected AlterationNotifier<Node>::ObserverBase,
403 protected AlterationNotifier<Edge>::ObserverBase
408 std::list<Node> added_nodes;
409 std::list<Edge> added_edges;
412 virtual void add(const Node& n) {
413 added_nodes.push_back(n);
417 virtual void erase(const Node&)
421 virtual void add(const Edge& n) {
422 added_edges.push_back(n);
426 virtual void erase(const Edge&)
431 void regist(ListGraph &_g) {
433 AlterationNotifier<Node>::ObserverBase::
434 attach(g->node_observers);
435 AlterationNotifier<Edge>::ObserverBase::
436 attach(g->edge_observers);
440 AlterationNotifier<Node>::ObserverBase::
442 AlterationNotifier<Edge>::ObserverBase::
448 ///Default constructur.
450 ///Default constructur.
451 ///To actually make a snapshot you must call save().
454 ///Constructor that immediately makes a snapshot.
456 ///This constructor immediately makes a snapshot of the graph.
457 ///\param _g The graph we make a snapshot of.
458 SnapShot(ListGraph &_g) {
461 ///\bug Is it necessary?
470 ///Make a snapshot of the graph.
472 ///This function can be called more than once. In case of a repeated
473 ///call, the previous snapshot gets lost.
474 ///\param _g The graph we make the snapshot of.
475 void save(ListGraph &_g)
485 ///Undo the changes until the last snapshot.
487 ///Undo the changes until last snapshot created by save().
489 ///\todo This function might be called undo().
492 while(!added_edges.empty()) {
493 g->erase(added_edges.front());
494 added_edges.pop_front();
496 while(!added_nodes.empty()) {
497 g->erase(added_nodes.front());
498 added_nodes.pop_front();
506 /**************** Undirected List Graph ****************/
508 typedef ErasableUndirGraphExtender<
509 ClearableUndirGraphExtender<
510 ExtendableUndirGraphExtender<
511 MappableUndirGraphExtender<
512 IterableUndirGraphExtender<
513 AlterableUndirGraphExtender<
514 UndirGraphExtender<ListGraphBase> > > > > > > ErasableUndirListGraphBase;
516 ///An undirected list graph class.
518 ///This is a simple and fast erasable undirected graph implementation.
520 ///It conforms to the
521 ///\ref concept::UndirGraph "UndirGraph" concept.
523 ///\sa concept::UndirGraph.
525 ///\todo SnapShot hasn't been implemented yet.
527 class UndirListGraph : public ErasableUndirListGraphBase {