3 #ifndef HUGO_SMART_GRAPH_H
4 #define HUGO_SMART_GRAPH_H
8 ///\brief SmartGraph and SymSmartGraph classes.
13 #include <hugo/invalid.h>
15 #include <hugo/array_map.h>
16 #include <hugo/sym_map.h>
18 #include <hugo/map_registry.h>
20 #include <hugo/map_defines.h>
24 /// \addtogroup graphs
26 // class SymSmartGraph;
28 ///A smart graph class.
30 ///This is a simple and fast graph implementation.
31 ///It is also quite memory efficient, but at the price
32 ///that <b> it does not support node and edge deletion</b>.
34 ///the \ref skeleton::ExtendableGraph "ExtendableGraph" concept.
35 ///\sa skeleton::ExtendableGraph.
37 ///\todo Some member functions could be \c static.
39 ///\todo A possibly useful functionality: a function saveState() would
40 ///give back a data sturcture X and then the function restoreState(X)
41 ///would remove the nodes and edges added after the call of saveState().
42 ///Of course it should be used as a stack. (Maybe X is not necessary.)
44 ///\author Alpar Juttner
49 int first_in,first_out;
50 NodeT() : first_in(-1), first_out(-1) {}
54 int head, tail, next_in, next_out;
55 //FIXME: is this necessary?
56 EdgeT() : next_in(-1), next_out(-1) {}
59 std::vector<NodeT> nodes;
61 std::vector<EdgeT> edges;
66 typedef SmartGraph Graph;
76 // Create map registries.
77 CREATE_MAP_REGISTRIES;
78 // Create node and edge maps.
79 CREATE_MAPS(ArrayMap);
83 SmartGraph() : nodes(), edges() { }
84 SmartGraph(const SmartGraph &_g) : nodes(_g.nodes), edges(_g.edges) { }
87 int nodeNum() const { return nodes.size(); }
89 int edgeNum() const { return edges.size(); }
95 int maxNodeId() const { return nodes.size()-1; }
100 int maxEdgeId() const { return edges.size()-1; }
102 Node tail(Edge e) const { return edges[e.n].tail; }
103 Node head(Edge e) const { return edges[e.n].head; }
105 NodeIt& first(NodeIt& v) const {
106 v=NodeIt(*this); return v; }
107 EdgeIt& first(EdgeIt& e) const {
108 e=EdgeIt(*this); return e; }
109 OutEdgeIt& first(OutEdgeIt& e, const Node v) const {
110 e=OutEdgeIt(*this,v); return e; }
111 InEdgeIt& first(InEdgeIt& e, const Node v) const {
112 e=InEdgeIt(*this,v); return e; }
116 /// The ID of a valid Node is a nonnegative integer not greater than
117 /// \ref maxNodeId(). The range of the ID's is not surely continuous
118 /// and the greatest node ID can be actually less then \ref maxNodeId().
120 /// The ID of the \ref INVALID node is -1.
121 ///\return The ID of the node \c v.
122 static int id(Node v) { return v.n; }
125 /// The ID of a valid Edge is a nonnegative integer not greater than
126 /// \ref maxEdgeId(). The range of the ID's is not surely continuous
127 /// and the greatest edge ID can be actually less then \ref maxEdgeId().
129 /// The ID of the \ref INVALID edge is -1.
130 ///\return The ID of the edge \c e.
131 static int id(Edge e) { return e.n; }
134 Node n; n.n=nodes.size();
135 nodes.push_back(NodeT()); //FIXME: Hmmm...
142 Edge addEdge(Node u, Node v) {
143 Edge e; e.n=edges.size(); edges.push_back(EdgeT()); //FIXME: Hmmm...
144 edges[e.n].tail=u.n; edges[e.n].head=v.n;
145 edges[e.n].next_out=nodes[u.n].first_out;
146 edges[e.n].next_in=nodes[v.n].first_in;
147 nodes[u.n].first_out=nodes[v.n].first_in=e.n;
154 /// Finds an edge between two nodes.
156 /// Finds an edge from node \c u to node \c v.
158 /// If \c prev is \ref INVALID (this is the default value), then
159 /// It finds the first edge from \c u to \c v. Otherwise it looks for
160 /// the next edge from \c u to \c v after \c prev.
161 /// \return The found edge or INVALID if there is no such an edge.
162 Edge findEdge(Node u,Node v, Edge prev = INVALID)
164 int e = (prev.n==-1)? nodes[u.n].first_out : edges[prev.n].next_out;
165 while(e!=-1 && edges[e].tail!=v.n) e = edges[e].next_out;
178 friend class SmartGraph;
179 template <typename T> friend class NodeMap;
182 friend class OutEdgeIt;
183 friend class InEdgeIt;
184 friend class SymEdge;
188 friend int SmartGraph::id(Node v);
192 Node (Invalid) { n=-1; }
193 bool operator==(const Node i) const {return n==i.n;}
194 bool operator!=(const Node i) const {return n!=i.n;}
195 bool operator<(const Node i) const {return n<i.n;}
197 // operator bool() { return n!=-1; }
200 class NodeIt : public Node {
202 friend class SmartGraph;
204 NodeIt() : Node() { }
205 NodeIt(const SmartGraph& _G,Node n) : Node(n), G(&_G) { }
206 NodeIt(Invalid i) : Node(i) { }
207 NodeIt(const SmartGraph& _G) : Node(_G.nodes.size()?0:-1), G(&_G) { }
208 NodeIt &operator++() {
209 n=(n+2)%(G->nodes.size()+1)-1;
213 // operator bool() { return Node::operator bool(); }
217 friend class SmartGraph;
218 template <typename T> friend class EdgeMap;
220 friend class SymSmartGraph;
226 friend int SmartGraph::id(Edge e);
229 /// An Edge with id \c n.
232 Edge (Invalid) { n=-1; }
233 bool operator==(const Edge i) const {return n==i.n;}
234 bool operator!=(const Edge i) const {return n!=i.n;}
235 bool operator<(const Edge i) const {return n<i.n;}
237 // operator bool() { return n!=-1; }
239 ///Set the edge to that have ID \c ID.
240 void setToId(int id) { n=id; }
243 class EdgeIt : public Edge {
245 friend class SmartGraph;
247 EdgeIt(const SmartGraph& _G) : Edge(_G.edges.size()-1), G(&_G) { }
248 EdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
249 EdgeIt (Invalid i) : Edge(i) { }
250 EdgeIt() : Edge() { }
251 EdgeIt &operator++() { --n; return *this; }
253 // operator bool() { return Edge::operator bool(); }
256 class OutEdgeIt : public Edge {
258 friend class SmartGraph;
260 OutEdgeIt() : Edge() { }
261 OutEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
262 OutEdgeIt (Invalid i) : Edge(i) { }
264 OutEdgeIt(const SmartGraph& _G,const Node v)
265 : Edge(_G.nodes[v.n].first_out), G(&_G) {}
266 OutEdgeIt &operator++() { n=G->edges[n].next_out; return *this; }
268 // operator bool() { return Edge::operator bool(); }
271 class InEdgeIt : public Edge {
273 friend class SmartGraph;
275 InEdgeIt() : Edge() { }
276 InEdgeIt(const SmartGraph& _G, Edge e) : Edge(e), G(&_G) { }
277 InEdgeIt (Invalid i) : Edge(i) { }
278 InEdgeIt(const SmartGraph& _G,Node v)
279 : Edge(_G.nodes[v.n].first_in), G(&_G) { }
280 InEdgeIt &operator++() { n=G->edges[n].next_in; return *this; }
282 // operator bool() { return Edge::operator bool(); }
287 ///Graph for bidirectional edges.
289 ///The purpose of this graph structure is to handle graphs
290 ///having bidirectional edges. Here the function \c addEdge(u,v) adds a pair
291 ///of oppositely directed edges.
292 ///There is a new edge map type called
293 ///\ref SymSmartGraph::SymEdgeMap "SymEdgeMap"
294 ///that complements this
296 ///storing shared values for the edge pairs. The usual
297 ///\ref Graph::EdgeMap "EdgeMap"
301 ///The oppositely directed edge can also be obtained easily
302 ///using \ref opposite.
303 ///\warning It shares the similarity with \ref SmartGraph that
304 ///it is not possible to delete edges or nodes from the graph.
307 class SymSmartGraph : public SmartGraph
310 typedef SymSmartGraph Graph;
312 // Create symmetric map registry.
313 CREATE_SYM_EDGE_MAP_REGISTRY;
314 // Create symmetric edge map.
315 CREATE_SYM_EDGE_MAP(ArrayMap);
318 SymSmartGraph() : SmartGraph() { }
319 SymSmartGraph(const SmartGraph &_g) : SmartGraph(_g) { }
320 ///Adds a pair of oppositely directed edges to the graph.
321 Edge addEdge(Node u, Node v)
323 Edge e = SmartGraph::addEdge(u,v);
324 Edge f = SmartGraph::addEdge(v,u);
325 sym_edge_maps.add(e);
326 sym_edge_maps.add(f);
330 ///The oppositely directed edge.
332 ///Returns the oppositely directed
333 ///pair of the edge \c e.
334 static Edge opposite(Edge e)
337 f.n = e.n - 2*(e.n%2) + 1;
350 #endif //HUGO_SMART_GRAPH_H