This way it works also when both GLPK and CPLEX are enabled.
2 * src/lemon/path.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
18 @defgroup paths Path Structures
20 \brief Path structures implemented in LEMON.
22 LEMON provides flexible data structures
25 All of them have the same interface, especially they can be built or extended
26 using a standard Builder subclass. This make is easy to have e.g. the Dijkstra
27 algorithm to store its result in any kind of path structure.
29 \sa lemon::concept::Path
35 ///\brief Classes for representing paths in graphs.
37 ///\todo Iterators have obsolete style
46 #include <lemon/invalid.h>
54 //! \brief A structure for representing directed paths in a graph.
56 //! A structure for representing directed path in a graph.
57 //! \param Graph The graph type in which the path is.
58 //! \param DM DebugMode, defaults to DefaultDebugMode.
60 //! In a sense, the path can be treated as a graph, for is has \c NodeIt
61 //! and \c EdgeIt with the same usage. These types converts to the \c Node
62 //! and \c Edge of the original graph.
64 //! \todo Thoroughfully check all the range and consistency tests.
65 template<typename Graph>
68 /// Edge type of the underlying graph.
69 typedef typename Graph::Edge GraphEdge;
70 /// Node type of the underlying graph.
71 typedef typename Graph::Node GraphNode;
77 typedef std::vector<GraphEdge> Container;
82 /// \param _G The graph in which the path is.
84 DirPath(const Graph &_G) : gr(&_G) {}
86 /// \brief Subpath constructor.
88 /// Subpath defined by two nodes.
89 /// \warning It is an error if the two edges are not in order!
90 DirPath(const DirPath &P, const NodeIt &a, const NodeIt &b) {
92 edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
95 /// \brief Subpath constructor.
97 /// Subpath defined by two edges. Contains edges in [a,b)
98 /// \warning It is an error if the two edges are not in order!
99 DirPath(const DirPath &P, const EdgeIt &a, const EdgeIt &b) {
101 edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
104 /// Length of the path.
105 int length() const { return edges.size(); }
106 /// Returns whether the path is empty.
107 bool empty() const { return edges.empty(); }
109 /// Resets the path to an empty path.
110 void clear() { edges.clear(); }
112 /// \brief Starting point of the path.
114 /// Starting point of the path.
115 /// Returns INVALID if the path is empty.
116 GraphNode source() const {
117 return empty() ? INVALID : gr->source(edges[0]);
119 /// \brief End point of the path.
121 /// End point of the path.
122 /// Returns INVALID if the path is empty.
123 GraphNode target() const {
124 return empty() ? INVALID : gr->target(edges[length()-1]);
127 /// \brief Initializes node or edge iterator to point to the first
131 template<typename It>
132 It& first(It &i) const { return i=It(*this); }
134 /// \brief Initializes node iterator to point to the node of a given index.
135 NodeIt& nth(NodeIt &i, int n) const {
136 return i=NodeIt(*this, n);
139 /// \brief Initializes edge iterator to point to the edge of a given index.
140 EdgeIt& nth(EdgeIt &i, int n) const {
141 return i=EdgeIt(*this, n);
144 /// \brief Returns node iterator pointing to the target node of the
145 /// given edge iterator.
146 NodeIt target(const EdgeIt& e) const {
147 return NodeIt(*this, e.idx+1);
150 /// \brief Returns node iterator pointing to the source node of the
151 /// given edge iterator.
152 NodeIt source(const EdgeIt& e) const {
153 return NodeIt(*this, e.idx);
157 /* Iterator classes */
160 * \brief Iterator class to iterate on the edges of the paths
162 * This class is used to iterate on the edges of the paths
164 * Of course it converts to Graph::Edge
168 friend class DirPath;
173 /// Default constructor
175 /// Invalid constructor
176 EdgeIt(Invalid) : idx(-1), p(0) {}
177 /// Constructor with starting point
178 EdgeIt(const DirPath &_p, int _idx = 0) :
179 idx(_idx), p(&_p) { validate(); }
182 bool valid() const { return idx!=-1; }
184 ///Conversion to Graph::Edge
185 operator GraphEdge () const {
186 return valid() ? p->edges[idx] : INVALID;
190 EdgeIt& operator++() { ++idx; validate(); return *this; }
192 /// Comparison operator
193 bool operator==(const EdgeIt& e) const { return idx==e.idx; }
194 /// Comparison operator
195 bool operator!=(const EdgeIt& e) const { return idx!=e.idx; }
196 /// Comparison operator
197 bool operator<(const EdgeIt& e) const { return idx<e.idx; }
200 void validate() { if(idx >= p->length() ) idx=-1; }
204 * \brief Iterator class to iterate on the nodes of the paths
206 * This class is used to iterate on the nodes of the paths
208 * Of course it converts to Graph::Node
212 friend class DirPath;
217 /// Default constructor
219 /// Invalid constructor
220 NodeIt(Invalid) : idx(-1), p(0) {}
221 /// Constructor with starting point
222 NodeIt(const DirPath &_p, int _idx = 0) :
223 idx(_idx), p(&_p) { validate(); }
226 bool valid() const { return idx!=-1; }
228 ///Conversion to Graph::Node
229 operator const GraphNode& () const {
230 if(idx >= p->length())
233 return p->gr->source(p->edges[idx]);
238 NodeIt& operator++() { ++idx; validate(); return *this; }
240 /// Comparison operator
241 bool operator==(const NodeIt& e) const { return idx==e.idx; }
242 /// Comparison operator
243 bool operator!=(const NodeIt& e) const { return idx!=e.idx; }
244 /// Comparison operator
245 bool operator<(const NodeIt& e) const { return idx<e.idx; }
248 void validate() { if(idx > p->length() ) idx=-1; }
251 friend class Builder;
254 * \brief Class to build paths
256 * This class is used to fill a path with edges.
258 * You can push new edges to the front and to the back of the path in
259 * arbitrary order then you should commit these changes to the graph.
261 * Fundamentally, for most "Paths" (classes fulfilling the
262 * PathConcept) while the builder is active (after the first modifying
263 * operation and until the commit()) the original Path is in a
264 * "transitional" state (operations on it have undefined result). But
265 * in the case of DirPath the original path remains unchanged until the
266 * commit. However we don't recomend that you use this feature.
270 Container front, back;
273 ///\param _p the path you want to fill in.
275 Builder(DirPath &_p) : P(_p) {}
277 /// Sets the starting node of the path.
279 /// Sets the starting node of the path. Edge added to the path
280 /// afterwards have to be incident to this node.
281 /// It should be called if and only if
282 /// the path is empty and before any call to
283 /// \ref pushFront() or \ref pushBack()
284 void setStartNode(const GraphNode &) {}
286 ///Push a new edge to the front of the path
288 ///Push a new edge to the front of the path.
290 void pushFront(const GraphEdge& e) {
294 ///Push a new edge to the back of the path
296 ///Push a new edge to the back of the path.
298 void pushBack(const GraphEdge& e) {
302 ///Commit the changes to the path.
304 if( !front.empty() || !back.empty() ) {
306 tmp.reserve(front.size()+back.size()+P.length());
307 tmp.insert(tmp.end(), front.rbegin(), front.rend());
308 tmp.insert(tmp.end(), P.edges.begin(), P.edges.end());
309 tmp.insert(tmp.end(), back.begin(), back.end());
316 ///Reserve storage for the builder in advance.
318 ///If you know a reasonable upper bound of the number of the edges
319 ///to add to the front, using this function you can speed up the building.
321 void reserveFront(size_t r) {front.reserve(r);}
323 ///Reserve storage for the builder in advance.
325 ///If you know a reasonable upper bound of the number of the edges
326 ///to add to the back, using this function you can speed up the building.
328 void reserveBack(size_t r) {back.reserve(r);}
332 return front.empty() && back.empty() && P.empty();
335 GraphNode source() const {
336 if( ! front.empty() )
337 return P.gr->source(front[front.size()-1]);
338 else if( ! P.empty() )
339 return P.gr->source(P.edges[0]);
340 else if( ! back.empty() )
341 return P.gr->source(back[0]);
345 GraphNode target() const {
347 return P.gr->target(back[back.size()-1]);
348 else if( ! P.empty() )
349 return P.gr->target(P.edges[P.length()-1]);
350 else if( ! front.empty() )
351 return P.gr->target(front[0]);
369 /**********************************************************************/
372 //! \brief A structure for representing undirected path in a graph.
374 //! A structure for representing undirected path in a graph. Ie. this is
375 //! a path in a \e directed graph but the edges should not be directed
378 //! \param Graph The graph type in which the path is.
379 //! \param DM DebugMode, defaults to DefaultDebugMode.
381 //! In a sense, the path can be treated as a graph, for is has \c NodeIt
382 //! and \c EdgeIt with the same usage. These types converts to the \c Node
383 //! and \c Edge of the original graph.
385 //! \todo Thoroughfully check all the range and consistency tests.
386 template<typename Graph>
389 /// Edge type of the underlying graph.
390 typedef typename Graph::Edge GraphEdge;
391 /// Node type of the underlying graph.
392 typedef typename Graph::Node GraphNode;
398 typedef std::vector<GraphEdge> Container;
403 /// \param _G The graph in which the path is.
405 UndirPath(const Graph &_G) : gr(&_G) {}
407 /// \brief Subpath constructor.
409 /// Subpath defined by two nodes.
410 /// \warning It is an error if the two edges are not in order!
411 UndirPath(const UndirPath &P, const NodeIt &a, const NodeIt &b) {
413 edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
416 /// \brief Subpath constructor.
418 /// Subpath defined by two edges. Contains edges in [a,b)
419 /// \warning It is an error if the two edges are not in order!
420 UndirPath(const UndirPath &P, const EdgeIt &a, const EdgeIt &b) {
422 edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx);
425 /// Length of the path.
426 size_t length() const { return edges.size(); }
427 /// Returns whether the path is empty.
428 bool empty() const { return edges.empty(); }
430 /// Resets the path to an empty path.
431 void clear() { edges.clear(); }
433 /// \brief Starting point of the path.
435 /// Starting point of the path.
436 /// Returns INVALID if the path is empty.
437 GraphNode source() const {
438 return empty() ? INVALID : gr->source(edges[0]);
440 /// \brief End point of the path.
442 /// End point of the path.
443 /// Returns INVALID if the path is empty.
444 GraphNode target() const {
445 return empty() ? INVALID : gr->target(edges[length()-1]);
448 /// \brief Initializes node or edge iterator to point to the first
452 template<typename It>
453 It& first(It &i) const { return i=It(*this); }
455 /// \brief Initializes node iterator to point to the node of a given index.
456 NodeIt& nth(NodeIt &i, int n) const {
457 return i=NodeIt(*this, n);
460 /// \brief Initializes edge iterator to point to the edge of a given index.
461 EdgeIt& nth(EdgeIt &i, int n) const {
462 return i=EdgeIt(*this, n);
465 /// Checks validity of a node or edge iterator.
466 template<typename It>
468 bool valid(const It &i) { return i.valid(); }
470 /// Steps the given node or edge iterator.
471 template<typename It>
477 /// \brief Returns node iterator pointing to the target node of the
478 /// given edge iterator.
479 NodeIt target(const EdgeIt& e) const {
480 return NodeIt(*this, e.idx+1);
483 /// \brief Returns node iterator pointing to the source node of the
484 /// given edge iterator.
485 NodeIt source(const EdgeIt& e) const {
486 return NodeIt(*this, e.idx);
492 * \brief Iterator class to iterate on the edges of the paths
494 * This class is used to iterate on the edges of the paths
496 * Of course it converts to Graph::Edge
498 * \todo Its interface differs from the standard edge iterator.
502 friend class UndirPath;
507 /// Default constructor
509 /// Invalid constructor
510 EdgeIt(Invalid) : idx(-1), p(0) {}
511 /// Constructor with starting point
512 EdgeIt(const UndirPath &_p, int _idx = 0) :
513 idx(_idx), p(&_p) { validate(); }
516 bool valid() const { return idx!=-1; }
518 ///Conversion to Graph::Edge
519 operator GraphEdge () const {
520 return valid() ? p->edges[idx] : INVALID;
523 EdgeIt& operator++() { ++idx; validate(); return *this; }
525 /// Comparison operator
526 bool operator==(const EdgeIt& e) const { return idx==e.idx; }
527 /// Comparison operator
528 bool operator!=(const EdgeIt& e) const { return idx!=e.idx; }
529 /// Comparison operator
530 bool operator<(const EdgeIt& e) const { return idx<e.idx; }
533 // FIXME: comparison between signed and unsigned...
534 // Jo ez igy? Vagy esetleg legyen a length() int?
535 void validate() { if( size_t(idx) >= p->length() ) idx=-1; }
539 * \brief Iterator class to iterate on the nodes of the paths
541 * This class is used to iterate on the nodes of the paths
543 * Of course it converts to Graph::Node
545 * \todo Its interface differs from the standard node iterator.
549 friend class UndirPath;
554 /// Default constructor
556 /// Invalid constructor
557 NodeIt(Invalid) : idx(-1), p(0) {}
558 /// Constructor with starting point
559 NodeIt(const UndirPath &_p, int _idx = 0) :
560 idx(_idx), p(&_p) { validate(); }
563 bool valid() const { return idx!=-1; }
565 ///Conversion to Graph::Node
566 operator const GraphNode& () const {
567 if(idx >= p->length())
570 return p->gr->source(p->edges[idx]);
575 NodeIt& operator++() { ++idx; validate(); return *this; }
577 /// Comparison operator
578 bool operator==(const NodeIt& e) const { return idx==e.idx; }
579 /// Comparison operator
580 bool operator!=(const NodeIt& e) const { return idx!=e.idx; }
581 /// Comparison operator
582 bool operator<(const NodeIt& e) const { return idx<e.idx; }
585 void validate() { if( size_t(idx) > p->length() ) idx=-1; }
588 friend class Builder;
591 * \brief Class to build paths
593 * This class is used to fill a path with edges.
595 * You can push new edges to the front and to the back of the path in
596 * arbitrary order then you should commit these changes to the graph.
598 * Fundamentally, for most "Paths" (classes fulfilling the
599 * PathConcept) while the builder is active (after the first modifying
600 * operation and until the commit()) the original Path is in a
601 * "transitional" state (operations ot it have undefined result). But
602 * in the case of UndirPath the original path is unchanged until the
603 * commit. However we don't recomend that you use this feature.
607 Container front, back;
610 ///\param _p the path you want to fill in.
612 Builder(UndirPath &_p) : P(_p) {}
614 /// Sets the starting node of the path.
616 /// Sets the starting node of the path. Edge added to the path
617 /// afterwards have to be incident to this node.
618 /// It should be called if and only if
619 /// the path is empty and before any call to
620 /// \ref pushFront() or \ref pushBack()
621 void setStartNode(const GraphNode &) {}
623 ///Push a new edge to the front of the path
625 ///Push a new edge to the front of the path.
627 void pushFront(const GraphEdge& e) {
631 ///Push a new edge to the back of the path
633 ///Push a new edge to the back of the path.
635 void pushBack(const GraphEdge& e) {
639 ///Commit the changes to the path.
641 if( !(front.empty() && back.empty()) ) {
643 tmp.reserve(front.size()+back.size()+P.length());
644 tmp.insert(tmp.end(), front.rbegin(), front.rend());
645 tmp.insert(tmp.end(), P.edges.begin(), P.edges.end());
646 tmp.insert(tmp.end(), back.begin(), back.end());
654 ///Reserve storage for the builder in advance.
656 ///If you know a reasonable upper bound of the number of the edges
657 ///to add to the front, using this function you can speed up the building.
659 void reserveFront(size_t r) {front.reserve(r);}
661 ///Reserve storage for the builder in advance.
663 ///If you know a reasonable upper bound of the number of the edges
664 ///to add to the back, using this function you can speed up the building.
666 void reserveBack(size_t r) {back.reserve(r);}
670 return front.empty() && back.empty() && P.empty();
673 GraphNode source() const {
674 if( ! front.empty() )
675 return P.gr->source(front[front.size()-1]);
676 else if( ! P.empty() )
677 return P.gr->source(P.edges[0]);
678 else if( ! back.empty() )
679 return P.gr->source(back[0]);
683 GraphNode target() const {
685 return P.gr->target(back[back.size()-1]);
686 else if( ! P.empty() )
687 return P.gr->target(P.edges[P.length()-1]);
688 else if( ! front.empty() )
689 return P.gr->target(front[0]);
703 #endif // LEMON_PATH_H