1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/lemon/smart_graph.h Mon May 23 04:48:14 2005 +0000
1.3 @@ -0,0 +1,414 @@
1.4 +/* -*- C++ -*-
1.5 + * lemon/smart_graph.h - Part of LEMON, a generic C++ optimization library
1.6 + *
1.7 + * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
1.8 + * (Egervary Research Group on Combinatorial Optimization, EGRES).
1.9 + *
1.10 + * Permission to use, modify and distribute this software is granted
1.11 + * provided that this copyright notice appears in all copies. For
1.12 + * precise terms see the accompanying LICENSE file.
1.13 + *
1.14 + * This software is provided "AS IS" with no warranty of any kind,
1.15 + * express or implied, and with no claim as to its suitability for any
1.16 + * purpose.
1.17 + *
1.18 + */
1.19 +
1.20 +#ifndef LEMON_SMART_GRAPH_H
1.21 +#define LEMON_SMART_GRAPH_H
1.22 +
1.23 +///\ingroup graphs
1.24 +///\file
1.25 +///\brief SmartGraph and SymSmartGraph classes.
1.26 +
1.27 +#include <vector>
1.28 +
1.29 +#include <lemon/invalid.h>
1.30 +
1.31 +#include <lemon/bits/clearable_graph_extender.h>
1.32 +#include <lemon/bits/extendable_graph_extender.h>
1.33 +#include <lemon/bits/iterable_graph_extender.h>
1.34 +#include <lemon/bits/alteration_notifier.h>
1.35 +#include <lemon/bits/default_map.h>
1.36 +
1.37 +#include <lemon/bits/undir_graph_extender.h>
1.38 +
1.39 +#include <lemon/utility.h>
1.40 +
1.41 +namespace lemon {
1.42 +
1.43 + class SmartGraph;
1.44 + ///Base of SmartGraph
1.45 +
1.46 + ///Base of SmartGraph
1.47 + ///
1.48 + class SmartGraphBase {
1.49 +
1.50 + friend class SmatGraph;
1.51 +
1.52 + protected:
1.53 + struct NodeT
1.54 + {
1.55 + int first_in,first_out;
1.56 + NodeT() : first_in(-1), first_out(-1) {}
1.57 + };
1.58 + struct EdgeT
1.59 + {
1.60 + int target, source, next_in, next_out;
1.61 + //FIXME: is this necessary?
1.62 + EdgeT() : next_in(-1), next_out(-1) {}
1.63 + };
1.64 +
1.65 + std::vector<NodeT> nodes;
1.66 +
1.67 + std::vector<EdgeT> edges;
1.68 +
1.69 +
1.70 + public:
1.71 +
1.72 + typedef SmartGraphBase Graph;
1.73 +
1.74 + class Node;
1.75 + class Edge;
1.76 +
1.77 +
1.78 + public:
1.79 +
1.80 + SmartGraphBase() : nodes(), edges() { }
1.81 + SmartGraphBase(const SmartGraphBase &_g) : nodes(_g.nodes), edges(_g.edges) { }
1.82 +
1.83 + typedef True NodeNumTag;
1.84 + typedef True EdgeNumTag;
1.85 +
1.86 + ///Number of nodes.
1.87 + int nodeNum() const { return nodes.size(); }
1.88 + ///Number of edges.
1.89 + int edgeNum() const { return edges.size(); }
1.90 +
1.91 + /// Maximum node ID.
1.92 +
1.93 + /// Maximum node ID.
1.94 + ///\sa id(Node)
1.95 + int maxId(Node = INVALID) const { return nodes.size()-1; }
1.96 + /// Maximum edge ID.
1.97 +
1.98 + /// Maximum edge ID.
1.99 + ///\sa id(Edge)
1.100 + int maxId(Edge = INVALID) const { return edges.size()-1; }
1.101 +
1.102 + Node source(Edge e) const { return edges[e.n].source; }
1.103 + Node target(Edge e) const { return edges[e.n].target; }
1.104 +
1.105 + /// Node ID.
1.106 +
1.107 + /// The ID of a valid Node is a nonnegative integer not greater than
1.108 + /// \ref maxNodeId(). The range of the ID's is not surely continuous
1.109 + /// and the greatest node ID can be actually less then \ref maxNodeId().
1.110 + ///
1.111 + /// The ID of the \ref INVALID node is -1.
1.112 + ///\return The ID of the node \c v.
1.113 + static int id(Node v) { return v.n; }
1.114 + /// Edge ID.
1.115 +
1.116 + /// The ID of a valid Edge is a nonnegative integer not greater than
1.117 + /// \ref maxEdgeId(). The range of the ID's is not surely continuous
1.118 + /// and the greatest edge ID can be actually less then \ref maxEdgeId().
1.119 + ///
1.120 + /// The ID of the \ref INVALID edge is -1.
1.121 + ///\return The ID of the edge \c e.
1.122 + static int id(Edge e) { return e.n; }
1.123 +
1.124 + static Node fromId(int id, Node) { return Node(id);}
1.125 +
1.126 + static Edge fromId(int id, Edge) { return Edge(id);}
1.127 +
1.128 + Node addNode() {
1.129 + Node n; n.n=nodes.size();
1.130 + nodes.push_back(NodeT()); //FIXME: Hmmm...
1.131 + return n;
1.132 + }
1.133 +
1.134 + Edge addEdge(Node u, Node v) {
1.135 + Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
1.136 + edges[e.n].source=u.n; edges[e.n].target=v.n;
1.137 + edges[e.n].next_out=nodes[u.n].first_out;
1.138 + edges[e.n].next_in=nodes[v.n].first_in;
1.139 + nodes[u.n].first_out=nodes[v.n].first_in=e.n;
1.140 +
1.141 + return e;
1.142 + }
1.143 +
1.144 + void clear() {
1.145 + edges.clear();
1.146 + nodes.clear();
1.147 + }
1.148 +
1.149 +
1.150 + class Node {
1.151 + friend class SmartGraphBase;
1.152 + friend class SmartGraph;
1.153 +
1.154 + protected:
1.155 + int n;
1.156 + ///\todo It should be removed (or at least define a setToId() instead).
1.157 + ///
1.158 + Node(int nn) {n=nn;}
1.159 + public:
1.160 + Node() {}
1.161 + Node (Invalid) { n=-1; }
1.162 + bool operator==(const Node i) const {return n==i.n;}
1.163 + bool operator!=(const Node i) const {return n!=i.n;}
1.164 + bool operator<(const Node i) const {return n<i.n;}
1.165 + };
1.166 +
1.167 +
1.168 + class Edge {
1.169 + friend class SmartGraphBase;
1.170 + friend class SmartGraph;
1.171 +
1.172 + protected:
1.173 + int n;
1.174 + ///\todo It should be removed (or at least define a setToId() instead).
1.175 + ///
1.176 + Edge(int nn) {n=nn;}
1.177 + public:
1.178 + Edge() { }
1.179 + Edge (Invalid) { n=-1; }
1.180 + bool operator==(const Edge i) const {return n==i.n;}
1.181 + bool operator!=(const Edge i) const {return n!=i.n;}
1.182 + bool operator<(const Edge i) const {return n<i.n;}
1.183 + };
1.184 +
1.185 + void first(Node& node) const {
1.186 + node.n = nodes.size() - 1;
1.187 + }
1.188 +
1.189 + static void next(Node& node) {
1.190 + --node.n;
1.191 + }
1.192 +
1.193 + void first(Edge& edge) const {
1.194 + edge.n = edges.size() - 1;
1.195 + }
1.196 +
1.197 + static void next(Edge& edge) {
1.198 + --edge.n;
1.199 + }
1.200 +
1.201 + void firstOut(Edge& edge, const Node& node) const {
1.202 + edge.n = nodes[node.n].first_out;
1.203 + }
1.204 +
1.205 + void nextOut(Edge& edge) const {
1.206 + edge.n = edges[edge.n].next_out;
1.207 + }
1.208 +
1.209 + void firstIn(Edge& edge, const Node& node) const {
1.210 + edge.n = nodes[node.n].first_in;
1.211 + }
1.212 +
1.213 + void nextIn(Edge& edge) const {
1.214 + edge.n = edges[edge.n].next_in;
1.215 + }
1.216 +
1.217 + Edge _findEdge(Node u,Node v, Edge prev = INVALID)
1.218 + {
1.219 + int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
1.220 + while(e!=-1 && edges[e].target!=v.n) e = edges[e].next_out;
1.221 + prev.n=e;
1.222 + return prev;
1.223 + }
1.224 +
1.225 + Node _split(Node n, bool connect = true)
1.226 + {
1.227 + Node b = addNode();
1.228 + nodes[b.n].first_out=nodes[n.n].first_out;
1.229 + nodes[n.n].first_out=-1;
1.230 + for(int i=nodes[b.n].first_out;i!=-1;i++) edges[i].source=b.n;
1.231 + if(connect) addEdge(n,b);
1.232 + return b;
1.233 + }
1.234 +
1.235 + };
1.236 +
1.237 + typedef AlterableGraphExtender<SmartGraphBase> AlterableSmartGraphBase;
1.238 + typedef IterableGraphExtender<AlterableSmartGraphBase> IterableSmartGraphBase;
1.239 + typedef DefaultMappableGraphExtender<IterableSmartGraphBase> MappableSmartGraphBase;
1.240 + typedef ExtendableGraphExtender<MappableSmartGraphBase> ExtendableSmartGraphBase;
1.241 + typedef ClearableGraphExtender<ExtendableSmartGraphBase> ClearableSmartGraphBase;
1.242 +
1.243 + /// \addtogroup graphs
1.244 + /// @{
1.245 +
1.246 + ///A smart graph class.
1.247 +
1.248 + ///This is a simple and fast graph implementation.
1.249 + ///It is also quite memory efficient, but at the price
1.250 + ///that <b> it does support only limited (only stack-like)
1.251 + ///node and edge deletions</b>.
1.252 + ///It conforms to
1.253 + ///the \ref concept::ExtendableGraph "ExtendableGraph" concept.
1.254 + ///\sa concept::ExtendableGraph.
1.255 + ///
1.256 + ///\author Alpar Juttner
1.257 + class SmartGraph : public ClearableSmartGraphBase {
1.258 + public:
1.259 + /// Finds an edge between two nodes.
1.260 +
1.261 + /// Finds an edge from node \c u to node \c v.
1.262 + ///
1.263 + /// If \c prev is \ref INVALID (this is the default value), then
1.264 + /// it finds the first edge from \c u to \c v. Otherwise it looks for
1.265 + /// the next edge from \c u to \c v after \c prev.
1.266 + /// \return The found edge or \ref INVALID if there is no such an edge.
1.267 + ///
1.268 + /// Thus you can iterate through each edge from \c u to \c v as it follows.
1.269 + /// \code
1.270 + /// for(Edge e=G.findEdge(u,v);e!=INVALID;e=G.findEdge(u,v,e)) {
1.271 + /// ...
1.272 + /// }
1.273 + /// \endcode
1.274 + /// \todo Possibly it should be a global function.
1.275 + Edge findEdge(Node u,Node v, Edge prev = INVALID)
1.276 + {
1.277 + return _findEdge(u,v,prev);
1.278 + }
1.279 +
1.280 + class SnapShot;
1.281 + friend class SnapShot;
1.282 +
1.283 + protected:
1.284 + void restoreSnapShot(const SnapShot &s)
1.285 + {
1.286 + while(s.edge_num>edges.size()) {
1.287 + Parent::getNotifier(Edge()).erase(Edge(edges.size()-1));
1.288 + nodes[edges.back().target].first_in=edges.back().next_in;
1.289 + nodes[edges.back().source].first_out=edges.back().next_out;
1.290 + edges.pop_back();
1.291 + }
1.292 + //nodes.resize(s.nodes_num);
1.293 + while(s.node_num>nodes.size()) {
1.294 + Parent::getNotifier(Node()).erase(Node(nodes.size()-1));
1.295 + nodes.pop_back();
1.296 + }
1.297 + }
1.298 +
1.299 + public:
1.300 +
1.301 + ///Split a node.
1.302 +
1.303 + ///This function splits a node. First a new node is added to the graph,
1.304 + ///then the source of each outgoing edge of \c n is moved to this new node.
1.305 + ///If \c connect is \c true (this is the default value), then a new edge
1.306 + ///from \c n to the newly created node is also added.
1.307 + ///\return The newly created node.
1.308 + ///
1.309 + ///\note The <tt>Edge</tt>s
1.310 + ///referencing a moved edge remain
1.311 + ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s
1.312 + ///may be invalidated.
1.313 + ///\warning This functionality cannot be used together with the SnapShot
1.314 + ///feature.
1.315 + ///\todo It could be implemented in a bit faster way.
1.316 + Node split(Node n, bool connect = true)
1.317 + {
1.318 + return _split(n,connect);
1.319 + }
1.320 +
1.321 +
1.322 + ///Class to make a snapshot of the graph and to restrore to it later.
1.323 +
1.324 + ///Class to make a snapshot of the graph and to restrore to it later.
1.325 + ///
1.326 + ///The newly added nodes and edges can be removed using the
1.327 + ///restore() function.
1.328 + ///\note After you restore a state, you cannot restore
1.329 + ///a later state, in other word you cannot add again the edges deleted
1.330 + ///by restore() using another SnapShot instance.
1.331 + ///
1.332 + class SnapShot
1.333 + {
1.334 + SmartGraph *g;
1.335 + protected:
1.336 + friend class SmartGraph;
1.337 + unsigned int node_num;
1.338 + unsigned int edge_num;
1.339 + public:
1.340 + ///Default constructor.
1.341 +
1.342 + ///Default constructor.
1.343 + ///To actually make a snapshot you must call save().
1.344 + ///
1.345 + SnapShot() : g(0) {}
1.346 + ///Constructor that immediately makes a snapshot
1.347 +
1.348 + ///This constructor immediately makes a snapshot of the graph.
1.349 + ///\param _g The graph we make a snapshot of.
1.350 + SnapShot(SmartGraph &_g) :g(&_g) {
1.351 + node_num=g->nodes.size();
1.352 + edge_num=g->edges.size();
1.353 + }
1.354 +
1.355 + ///Make a snapshot.
1.356 +
1.357 + ///Make a snapshot of the graph.
1.358 + ///
1.359 + ///This function can be called more than once. In case of a repeated
1.360 + ///call, the previous snapshot gets lost.
1.361 + ///\param _g The graph we make the snapshot of.
1.362 + void save(SmartGraph &_g)
1.363 + {
1.364 + g=&_g;
1.365 + node_num=g->nodes.size();
1.366 + edge_num=g->edges.size();
1.367 + }
1.368 +
1.369 + ///Undo the changes until a snapshot.
1.370 +
1.371 + ///Undo the changes until a snapshot created by save().
1.372 + ///
1.373 + ///\param s an internal stucture given back by save()
1.374 + ///\note After you restored a state, you cannot restore
1.375 + ///a later state, in other word you cannot add again the edges deleted
1.376 + ///by restore().
1.377 + ///
1.378 + ///\todo This function might be called undo().
1.379 +
1.380 + void restore()
1.381 + {
1.382 + g->restoreSnapShot(*this);
1.383 + }
1.384 + };
1.385 + };
1.386 +
1.387 +
1.388 + /**************** Undirected List Graph ****************/
1.389 +
1.390 + typedef ClearableUndirGraphExtender<
1.391 + ExtendableUndirGraphExtender<
1.392 + MappableUndirGraphExtender<
1.393 + IterableUndirGraphExtender<
1.394 + AlterableUndirGraphExtender<
1.395 + UndirGraphExtender<SmartGraphBase> > > > > > UndirSmartGraphBase;
1.396 +
1.397 + ///A smart undirected graph class.
1.398 +
1.399 + ///This is a simple and fast undirected graph implementation.
1.400 + ///It is also quite memory efficient, but at the price
1.401 + ///that <b> it does support only limited (only stack-like)
1.402 + ///node and edge deletions</b>.
1.403 + ///Except from this it conforms to
1.404 + ///the \ref concept::UndirGraph "UndirGraph" concept.
1.405 + ///\sa concept::UndirGraph.
1.406 + ///
1.407 + ///\todo SnapShot hasn't been implemented yet.
1.408 + ///
1.409 + class UndirSmartGraph : public UndirSmartGraphBase {
1.410 + };
1.411 +
1.412 +
1.413 + /// @}
1.414 +} //namespace lemon
1.415 +
1.416 +
1.417 +#endif //LEMON_SMART_GRAPH_H