2 * lemon/list_graph.h - Part of LEMON, a generic C++ optimization library
4 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Research Group on Combinatorial Optimization, 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 classes.
24 #include <lemon/bits/erasable_graph_extender.h>
25 #include <lemon/bits/clearable_graph_extender.h>
26 #include <lemon/bits/extendable_graph_extender.h>
27 #include <lemon/bits/iterable_graph_extender.h>
28 #include <lemon/bits/alteration_notifier.h>
29 #include <lemon/bits/default_map.h>
31 #include <lemon/bits/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 static Node fromId(int id, Node) { return Node(id);}
166 static Edge fromId(int id, Edge) { return Edge(id);}
168 /// Adds a new node to the graph.
170 /// \warning It adds the new node to the front of the list.
171 /// (i.e. the lastly added node becomes the first.)
175 if(first_free_node==-1) {
177 nodes.push_back(NodeT());
180 first_free_node = nodes[n].next;
183 nodes[n].next = first_node;
184 if(first_node != -1) nodes[first_node].prev = n;
188 nodes[n].first_in = nodes[n].first_out = -1;
193 Edge addEdge(Node u, Node v) {
196 if (first_free_edge == -1) {
198 edges.push_back(EdgeT());
201 first_free_edge = edges[n].next_in;
204 edges[n].source = u.id;
205 edges[n].target = v.id;
207 edges[n].next_out = nodes[u.id].first_out;
208 if(nodes[u.id].first_out != -1) {
209 edges[nodes[u.id].first_out].prev_out = n;
212 edges[n].next_in = nodes[v.id].first_in;
213 if(nodes[v.id].first_in != -1) {
214 edges[nodes[v.id].first_in].prev_in = n;
217 edges[n].prev_in = edges[n].prev_out = -1;
219 nodes[u.id].first_out = nodes[v.id].first_in = n;
224 void erase(const Node& node) {
227 if(nodes[n].next != -1) {
228 nodes[nodes[n].next].prev = nodes[n].prev;
231 if(nodes[n].prev != -1) {
232 nodes[nodes[n].prev].next = nodes[n].next;
234 first_node = nodes[n].next;
237 nodes[n].next = first_free_node;
242 void erase(const Edge& edge) {
245 if(edges[n].next_in!=-1) {
246 edges[edges[n].next_in].prev_in = edges[n].prev_in;
249 if(edges[n].prev_in!=-1) {
250 edges[edges[n].prev_in].next_in = edges[n].next_in;
252 nodes[edges[n].target].first_in = edges[n].next_in;
256 if(edges[n].next_out!=-1) {
257 edges[edges[n].next_out].prev_out = edges[n].prev_out;
260 if(edges[n].prev_out!=-1) {
261 edges[edges[n].prev_out].next_out = edges[n].next_out;
263 nodes[edges[n].source].first_out = edges[n].next_out;
266 edges[n].next_in = first_free_edge;
274 first_node = first_free_node = first_free_edge = -1;
278 void _changeTarget(Edge e, Node n)
280 if(edges[e.id].next_in != -1)
281 edges[edges[e.id].next_in].prev_in = edges[e.id].prev_in;
282 if(edges[e.id].prev_in != -1)
283 edges[edges[e.id].prev_in].next_in = edges[e.id].next_in;
284 else nodes[edges[e.id].target].first_in = edges[e.id].next_in;
285 edges[e.id].target = n.id;
286 edges[e.id].prev_in = -1;
287 edges[e.id].next_in = nodes[n.id].first_in;
288 nodes[n.id].first_in = e.id;
290 void _changeSource(Edge e, Node n)
292 if(edges[e.id].next_out != -1)
293 edges[edges[e.id].next_out].prev_out = edges[e.id].prev_out;
294 if(edges[e.id].prev_out != -1)
295 edges[edges[e.id].prev_out].next_out = edges[e.id].next_out;
296 else nodes[edges[e.id].source].first_out = edges[e.id].next_out;
297 edges[e.id].source = n.id;
298 edges[e.id].prev_out = -1;
299 edges[e.id].next_out = nodes[n.id].first_out;
300 nodes[n.id].first_out = e.id;
305 typedef AlterableGraphExtender<ListGraphBase> AlterableListGraphBase;
306 typedef IterableGraphExtender<AlterableListGraphBase> IterableListGraphBase;
307 typedef MappableGraphExtender<IterableListGraphBase> MappableListGraphBase;
308 typedef ExtendableGraphExtender<MappableListGraphBase> ExtendableListGraphBase;
309 typedef ClearableGraphExtender<ExtendableListGraphBase> ClearableListGraphBase;
310 typedef ErasableGraphExtender<
311 ClearableGraphExtender<
312 ExtendableGraphExtender<
313 MappableGraphExtender<
314 IterableGraphExtender<
315 AlterableGraphExtender<ListGraphBase> > > > > > ExtendedListGraphBase;
317 /// \addtogroup graphs
320 ///A list graph class.
322 ///This is a simple and fast erasable graph implementation.
324 ///It addition that it conforms to the
325 ///\ref concept::ErasableGraph "ErasableGraph" concept,
326 ///it also provides several additional useful extra functionalities.
327 ///\sa concept::ErasableGraph.
329 class ListGraph : public ExtendedListGraphBase
332 /// Changes the target of \c e to \c n
334 /// Changes the target of \c e to \c n
336 ///\note The <tt>Edge</tt>'s and <tt>OutEdge</tt>'s
337 ///referencing the changed edge remain
338 ///valid. However <tt>InEdge</tt>'s are invalidated.
339 void changeTarget(Edge e, Node n) { _changeTarget(e,n); }
340 /// Changes the source of \c e to \c n
342 /// Changes the source of \c e to \c n
344 ///\note The <tt>Edge</tt>'s and <tt>InEdge</tt>'s
345 ///referencing the changed edge remain
346 ///valid. However <tt>OutEdge</tt>'s are invalidated.
347 void changeSource(Edge e, Node n) { _changeSource(e,n); }
349 /// Invert the direction of an edge.
351 ///\note The <tt>Edge</tt>'s
352 ///referencing the changed edge remain
353 ///valid. However <tt>OutEdge</tt>'s and <tt>InEdge</tt>'s are invalidated.
354 void reverseEdge(Edge e) {
356 _changeTarget(e,source(e));
360 ///Using this it possible to avoid the superfluous memory allocation.
362 ///Using this it possible to avoid the superfluous memory allocation.
363 ///\todo more docs...
364 void reserveEdge(int n) { edges.reserve(n); };
366 ///Contract two nodes.
368 ///This function contracts two nodes.
370 ///Node \p b will be removed but instead of deleting
371 ///its neighboring edges, they will be joined to \p a.
372 ///The last parameter \p r controls whether to remove loops. \c true
373 ///means that loops will be removed.
375 ///\note The <tt>Edge</tt>s
376 ///referencing a moved edge remain
377 ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
378 ///may be invalidated.
379 void contract(Node a,Node b,bool r=true)
381 for(OutEdgeIt e(*this,b);e!=INVALID;) {
384 if(r && target(e)==a) erase(e);
385 else changeSource(e,a);
388 for(InEdgeIt e(*this,b);e!=INVALID;) {
391 if(r && source(e)==a) erase(e);
392 else changeTarget(e,a);
400 ///This function splits a node. First a new node is added to the graph,
401 ///then the source of each outgoing edge of \c n is moved to this new node.
402 ///If \c connect is \c true (this is the default value), then a new edge
403 ///from \c n to the newly created node is also added.
404 ///\return The newly created node.
406 ///\note The <tt>Edge</tt>s
407 ///referencing a moved edge remain
408 ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
409 ///may be invalidated.
410 ///\warning This functionality cannot be used together with the SnapShot
412 ///\todo It could be implemented in a bit faster way.
413 Node split(Node n, bool connect = true)
416 for(OutEdgeIt e(*this,n);e!=INVALID;) {
422 if(connect) addEdge(n,b);
426 ///Class to make a snapshot of the graph and to restrore to it later.
428 ///Class to make a snapshot of the graph and to restrore to it later.
430 ///The newly added nodes and edges can be removed using the
431 ///restore() function.
433 ///\warning Edge and node deletions cannot be restored.
434 ///\warning SnapShots cannot be nested.
435 ///\todo \c SnapShot or \c Snapshot?
436 class SnapShot : protected AlterationNotifier<Node>::ObserverBase,
437 protected AlterationNotifier<Edge>::ObserverBase
442 std::list<Node> added_nodes;
443 std::list<Edge> added_edges;
446 virtual void add(const Node& n) {
447 added_nodes.push_back(n);
451 virtual void erase(const Node&)
455 virtual void add(const Edge& n) {
456 added_edges.push_back(n);
460 virtual void erase(const Edge&)
465 ///\bug What is this used for?
467 virtual void build() {}
468 ///\bug What is this used for?
470 virtual void clear() {}
472 void regist(ListGraph &_g) {
474 AlterationNotifier<Node>::ObserverBase::
475 attach(g->getNotifier(Node()));
476 AlterationNotifier<Edge>::ObserverBase::
477 attach(g->getNotifier(Edge()));
481 AlterationNotifier<Node>::ObserverBase::
483 AlterationNotifier<Edge>::ObserverBase::
489 ///Default constructur.
491 ///Default constructur.
492 ///To actually make a snapshot you must call save().
495 ///Constructor that immediately makes a snapshot.
497 ///This constructor immediately makes a snapshot of the graph.
498 ///\param _g The graph we make a snapshot of.
499 SnapShot(ListGraph &_g) {
502 ///\bug Is it necessary?
511 ///Make a snapshot of the graph.
513 ///This function can be called more than once. In case of a repeated
514 ///call, the previous snapshot gets lost.
515 ///\param _g The graph we make the snapshot of.
516 void save(ListGraph &_g)
526 ///Undo the changes until the last snapshot.
528 ///Undo the changes until last snapshot created by save().
530 ///\todo This function might be called undo().
534 while(!added_edges.empty()) {
535 old_g.erase(added_edges.front());
536 added_edges.pop_front();
538 while(!added_nodes.empty()) {
539 old_g.erase(added_nodes.front());
540 added_nodes.pop_front();
549 /**************** Undirected List Graph ****************/
551 typedef ErasableUndirGraphExtender<
552 ClearableUndirGraphExtender<
553 ExtendableUndirGraphExtender<
554 MappableUndirGraphExtender<
555 IterableUndirGraphExtender<
556 AlterableUndirGraphExtender<
557 UndirGraphExtender<ListGraphBase> > > > > > > ExtendedUndirListGraphBase;
559 /// \addtogroup graphs
562 ///An undirected list graph class.
564 ///This is a simple and fast erasable undirected graph implementation.
566 ///It conforms to the
567 ///\ref concept::UndirGraph "UndirGraph" concept.
569 ///\sa concept::UndirGraph.
571 ///\todo SnapShot, reverseEdge(), changeTarget(), changeSource(), contract()
572 ///haven't been implemented yet.
574 class UndirListGraph : public ExtendedUndirListGraphBase {