diff -r d8475431bbbb -r 8e85e6bbefdf lemon/path.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lemon/path.h Mon May 23 04:48:14 2005 +0000 @@ -0,0 +1,703 @@ +/* -*- C++ -*- + * lemon/path.h - Part of LEMON, a generic C++ optimization library + * + * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport + * (Egervary Research Group on Combinatorial Optimization, EGRES). + * + * Permission to use, modify and distribute this software is granted + * provided that this copyright notice appears in all copies. For + * precise terms see the accompanying LICENSE file. + * + * This software is provided "AS IS" with no warranty of any kind, + * express or implied, and with no claim as to its suitability for any + * purpose. + * + */ + +/** +@defgroup paths Path Structures +@ingroup datas +\brief Path structures implemented in LEMON. + +LEMON provides flexible data structures +to work with paths. + +All of them have the same interface, especially they can be built or extended +using a standard Builder subclass. This make is easy to have e.g. the Dijkstra +algorithm to store its result in any kind of path structure. + +\sa lemon::concept::Path + +*/ + +///\ingroup paths +///\file +///\brief Classes for representing paths in graphs. +/// +///\todo Iterators have obsolete style + +#ifndef LEMON_PATH_H +#define LEMON_PATH_H + +#include +#include +#include + +#include + +namespace lemon { + + /// \addtogroup paths + /// @{ + + + //! \brief A structure for representing directed paths in a graph. + //! + //! A structure for representing directed path in a graph. + //! \param Graph The graph type in which the path is. + //! \param DM DebugMode, defaults to DefaultDebugMode. + //! + //! In a sense, the path can be treated as a graph, for is has \c NodeIt + //! and \c EdgeIt with the same usage. These types converts to the \c Node + //! and \c Edge of the original graph. + //! + //! \todo Thoroughfully check all the range and consistency tests. + template + class DirPath { + public: + /// Edge type of the underlying graph. + typedef typename Graph::Edge GraphEdge; + /// Node type of the underlying graph. + typedef typename Graph::Node GraphNode; + class NodeIt; + class EdgeIt; + + protected: + const Graph *gr; + typedef std::vector Container; + Container edges; + + public: + + /// \param _G The graph in which the path is. + /// + DirPath(const Graph &_G) : gr(&_G) {} + + /// \brief Subpath constructor. + /// + /// Subpath defined by two nodes. + /// \warning It is an error if the two edges are not in order! + DirPath(const DirPath &P, const NodeIt &a, const NodeIt &b) { + gr = P.gr; + edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); + } + + /// \brief Subpath constructor. + /// + /// Subpath defined by two edges. Contains edges in [a,b) + /// \warning It is an error if the two edges are not in order! + DirPath(const DirPath &P, const EdgeIt &a, const EdgeIt &b) { + gr = P.gr; + edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); + } + + /// Length of the path. + int length() const { return edges.size(); } + /// Returns whether the path is empty. + bool empty() const { return edges.empty(); } + + /// Resets the path to an empty path. + void clear() { edges.clear(); } + + /// \brief Starting point of the path. + /// + /// Starting point of the path. + /// Returns INVALID if the path is empty. + GraphNode source() const { + return empty() ? INVALID : gr->source(edges[0]); + } + /// \brief End point of the path. + /// + /// End point of the path. + /// Returns INVALID if the path is empty. + GraphNode target() const { + return empty() ? INVALID : gr->target(edges[length()-1]); + } + + /// \brief Initializes node or edge iterator to point to the first + /// node or edge. + /// + /// \sa nth + template + It& first(It &i) const { return i=It(*this); } + + /// \brief Initializes node iterator to point to the node of a given index. + NodeIt& nth(NodeIt &i, int n) const { + return i=NodeIt(*this, n); + } + + /// \brief Initializes edge iterator to point to the edge of a given index. + EdgeIt& nth(EdgeIt &i, int n) const { + return i=EdgeIt(*this, n); + } + + /// \brief Returns node iterator pointing to the target node of the + /// given edge iterator. + NodeIt target(const EdgeIt& e) const { + return NodeIt(*this, e.idx+1); + } + + /// \brief Returns node iterator pointing to the source node of the + /// given edge iterator. + NodeIt source(const EdgeIt& e) const { + return NodeIt(*this, e.idx); + } + + + /* Iterator classes */ + + /** + * \brief Iterator class to iterate on the edges of the paths + * + * This class is used to iterate on the edges of the paths + * + * Of course it converts to Graph::Edge + * + */ + class EdgeIt { + friend class DirPath; + + int idx; + const DirPath *p; + public: + /// Default constructor + EdgeIt() {} + /// Invalid constructor + EdgeIt(Invalid) : idx(-1), p(0) {} + /// Constructor with starting point + EdgeIt(const DirPath &_p, int _idx = 0) : + idx(_idx), p(&_p) { validate(); } + + ///Validity check + bool valid() const { return idx!=-1; } + + ///Conversion to Graph::Edge + operator GraphEdge () const { + return valid() ? p->edges[idx] : INVALID; + } + + /// Next edge + EdgeIt& operator++() { ++idx; validate(); return *this; } + + /// Comparison operator + bool operator==(const EdgeIt& e) const { return idx==e.idx; } + /// Comparison operator + bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } + /// Comparison operator + bool operator<(const EdgeIt& e) const { return idx= p->length() ) idx=-1; } + }; + + /** + * \brief Iterator class to iterate on the nodes of the paths + * + * This class is used to iterate on the nodes of the paths + * + * Of course it converts to Graph::Node + * + */ + class NodeIt { + friend class DirPath; + + int idx; + const DirPath *p; + public: + /// Default constructor + NodeIt() {} + /// Invalid constructor + NodeIt(Invalid) : idx(-1), p(0) {} + /// Constructor with starting point + NodeIt(const DirPath &_p, int _idx = 0) : + idx(_idx), p(&_p) { validate(); } + + ///Validity check + bool valid() const { return idx!=-1; } + + ///Conversion to Graph::Node + operator const GraphNode& () const { + if(idx >= p->length()) + return p->target(); + else if(idx >= 0) + return p->gr->source(p->edges[idx]); + else + return INVALID; + } + /// Next node + NodeIt& operator++() { ++idx; validate(); return *this; } + + /// Comparison operator + bool operator==(const NodeIt& e) const { return idx==e.idx; } + /// Comparison operator + bool operator!=(const NodeIt& e) const { return idx!=e.idx; } + /// Comparison operator + bool operator<(const NodeIt& e) const { return idx p->length() ) idx=-1; } + }; + + friend class Builder; + + /** + * \brief Class to build paths + * + * This class is used to fill a path with edges. + * + * You can push new edges to the front and to the back of the path in + * arbitrary order then you should commit these changes to the graph. + * + * Fundamentally, for most "Paths" (classes fulfilling the + * PathConcept) while the builder is active (after the first modifying + * operation and until the commit()) the original Path is in a + * "transitional" state (operations on it have undefined result). But + * in the case of DirPath the original path remains unchanged until the + * commit. However we don't recomend that you use this feature. + */ + class Builder { + DirPath &P; + Container front, back; + + public: + ///\param _p the path you want to fill in. + /// + Builder(DirPath &_p) : P(_p) {} + + /// Sets the starting node of the path. + + /// Sets the starting node of the path. Edge added to the path + /// afterwards have to be incident to this node. + /// It should be called if and only if + /// the path is empty and before any call to + /// \ref pushFront() or \ref pushBack() + void setStartNode(const GraphNode &) {} + + ///Push a new edge to the front of the path + + ///Push a new edge to the front of the path. + ///\sa setStartNode + void pushFront(const GraphEdge& e) { + front.push_back(e); + } + + ///Push a new edge to the back of the path + + ///Push a new edge to the back of the path. + ///\sa setStartNode + void pushBack(const GraphEdge& e) { + back.push_back(e); + } + + ///Commit the changes to the path. + void commit() { + if( !front.empty() || !back.empty() ) { + Container tmp; + tmp.reserve(front.size()+back.size()+P.length()); + tmp.insert(tmp.end(), front.rbegin(), front.rend()); + tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); + tmp.insert(tmp.end(), back.begin(), back.end()); + P.edges.swap(tmp); + front.clear(); + back.clear(); + } + } + + ///Reserve storage for the builder in advance. + + ///If you know a reasonable upper bound of the number of the edges + ///to add to the front, using this function you can speed up the building. + + void reserveFront(size_t r) {front.reserve(r);} + + ///Reserve storage for the builder in advance. + + ///If you know a reasonable upper bound of the number of the edges + ///to add to the back, using this function you can speed up the building. + + void reserveBack(size_t r) {back.reserve(r);} + + private: + bool empty() { + return front.empty() && back.empty() && P.empty(); + } + + GraphNode source() const { + if( ! front.empty() ) + return P.gr->source(front[front.size()-1]); + else if( ! P.empty() ) + return P.gr->source(P.edges[0]); + else if( ! back.empty() ) + return P.gr->source(back[0]); + else + return INVALID; + } + GraphNode target() const { + if( ! back.empty() ) + return P.gr->target(back[back.size()-1]); + else if( ! P.empty() ) + return P.gr->target(P.edges[P.length()-1]); + else if( ! front.empty() ) + return P.gr->target(front[0]); + else + return INVALID; + } + + }; + + }; + + + + + + + + + + + /**********************************************************************/ + + + //! \brief A structure for representing undirected path in a graph. + //! + //! A structure for representing undirected path in a graph. Ie. this is + //! a path in a \e directed graph but the edges should not be directed + //! forward. + //! + //! \param Graph The graph type in which the path is. + //! \param DM DebugMode, defaults to DefaultDebugMode. + //! + //! In a sense, the path can be treated as a graph, for is has \c NodeIt + //! and \c EdgeIt with the same usage. These types converts to the \c Node + //! and \c Edge of the original graph. + //! + //! \todo Thoroughfully check all the range and consistency tests. + template + class UndirPath { + public: + /// Edge type of the underlying graph. + typedef typename Graph::Edge GraphEdge; + /// Node type of the underlying graph. + typedef typename Graph::Node GraphNode; + class NodeIt; + class EdgeIt; + + protected: + const Graph *gr; + typedef std::vector Container; + Container edges; + + public: + + /// \param _G The graph in which the path is. + /// + UndirPath(const Graph &_G) : gr(&_G) {} + + /// \brief Subpath constructor. + /// + /// Subpath defined by two nodes. + /// \warning It is an error if the two edges are not in order! + UndirPath(const UndirPath &P, const NodeIt &a, const NodeIt &b) { + gr = P.gr; + edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); + } + + /// \brief Subpath constructor. + /// + /// Subpath defined by two edges. Contains edges in [a,b) + /// \warning It is an error if the two edges are not in order! + UndirPath(const UndirPath &P, const EdgeIt &a, const EdgeIt &b) { + gr = P.gr; + edges.insert(edges.end(), P.edges.begin()+a.idx, P.edges.begin()+b.idx); + } + + /// Length of the path. + size_t length() const { return edges.size(); } + /// Returns whether the path is empty. + bool empty() const { return edges.empty(); } + + /// Resets the path to an empty path. + void clear() { edges.clear(); } + + /// \brief Starting point of the path. + /// + /// Starting point of the path. + /// Returns INVALID if the path is empty. + GraphNode source() const { + return empty() ? INVALID : gr->source(edges[0]); + } + /// \brief End point of the path. + /// + /// End point of the path. + /// Returns INVALID if the path is empty. + GraphNode target() const { + return empty() ? INVALID : gr->target(edges[length()-1]); + } + + /// \brief Initializes node or edge iterator to point to the first + /// node or edge. + /// + /// \sa nth + template + It& first(It &i) const { return i=It(*this); } + + /// \brief Initializes node iterator to point to the node of a given index. + NodeIt& nth(NodeIt &i, int n) const { + return i=NodeIt(*this, n); + } + + /// \brief Initializes edge iterator to point to the edge of a given index. + EdgeIt& nth(EdgeIt &i, int n) const { + return i=EdgeIt(*this, n); + } + + /// Checks validity of a node or edge iterator. + template + static + bool valid(const It &i) { return i.valid(); } + + /// Steps the given node or edge iterator. + template + static + It& next(It &e) { + return ++e; + } + + /// \brief Returns node iterator pointing to the target node of the + /// given edge iterator. + NodeIt target(const EdgeIt& e) const { + return NodeIt(*this, e.idx+1); + } + + /// \brief Returns node iterator pointing to the source node of the + /// given edge iterator. + NodeIt source(const EdgeIt& e) const { + return NodeIt(*this, e.idx); + } + + + + /** + * \brief Iterator class to iterate on the edges of the paths + * + * This class is used to iterate on the edges of the paths + * + * Of course it converts to Graph::Edge + * + * \todo Its interface differs from the standard edge iterator. + * Yes, it shouldn't. + */ + class EdgeIt { + friend class UndirPath; + + int idx; + const UndirPath *p; + public: + /// Default constructor + EdgeIt() {} + /// Invalid constructor + EdgeIt(Invalid) : idx(-1), p(0) {} + /// Constructor with starting point + EdgeIt(const UndirPath &_p, int _idx = 0) : + idx(_idx), p(&_p) { validate(); } + + ///Validity check + bool valid() const { return idx!=-1; } + + ///Conversion to Graph::Edge + operator GraphEdge () const { + return valid() ? p->edges[idx] : INVALID; + } + /// Next edge + EdgeIt& operator++() { ++idx; validate(); return *this; } + + /// Comparison operator + bool operator==(const EdgeIt& e) const { return idx==e.idx; } + /// Comparison operator + bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } + /// Comparison operator + bool operator<(const EdgeIt& e) const { return idx= p->length() ) idx=-1; } + }; + + /** + * \brief Iterator class to iterate on the nodes of the paths + * + * This class is used to iterate on the nodes of the paths + * + * Of course it converts to Graph::Node + * + * \todo Its interface differs from the standard node iterator. + * Yes, it shouldn't. + */ + class NodeIt { + friend class UndirPath; + + int idx; + const UndirPath *p; + public: + /// Default constructor + NodeIt() {} + /// Invalid constructor + NodeIt(Invalid) : idx(-1), p(0) {} + /// Constructor with starting point + NodeIt(const UndirPath &_p, int _idx = 0) : + idx(_idx), p(&_p) { validate(); } + + ///Validity check + bool valid() const { return idx!=-1; } + + ///Conversion to Graph::Node + operator const GraphNode& () const { + if(idx >= p->length()) + return p->target(); + else if(idx >= 0) + return p->gr->source(p->edges[idx]); + else + return INVALID; + } + /// Next node + NodeIt& operator++() { ++idx; validate(); return *this; } + + /// Comparison operator + bool operator==(const NodeIt& e) const { return idx==e.idx; } + /// Comparison operator + bool operator!=(const NodeIt& e) const { return idx!=e.idx; } + /// Comparison operator + bool operator<(const NodeIt& e) const { return idx p->length() ) idx=-1; } + }; + + friend class Builder; + + /** + * \brief Class to build paths + * + * This class is used to fill a path with edges. + * + * You can push new edges to the front and to the back of the path in + * arbitrary order then you should commit these changes to the graph. + * + * Fundamentally, for most "Paths" (classes fulfilling the + * PathConcept) while the builder is active (after the first modifying + * operation and until the commit()) the original Path is in a + * "transitional" state (operations ot it have undefined result). But + * in the case of UndirPath the original path is unchanged until the + * commit. However we don't recomend that you use this feature. + */ + class Builder { + UndirPath &P; + Container front, back; + + public: + ///\param _p the path you want to fill in. + /// + Builder(UndirPath &_p) : P(_p) {} + + /// Sets the starting node of the path. + + /// Sets the starting node of the path. Edge added to the path + /// afterwards have to be incident to this node. + /// It should be called if and only if + /// the path is empty and before any call to + /// \ref pushFront() or \ref pushBack() + void setStartNode(const GraphNode &) {} + + ///Push a new edge to the front of the path + + ///Push a new edge to the front of the path. + ///\sa setStartNode + void pushFront(const GraphEdge& e) { + front.push_back(e); + } + + ///Push a new edge to the back of the path + + ///Push a new edge to the back of the path. + ///\sa setStartNode + void pushBack(const GraphEdge& e) { + back.push_back(e); + } + + ///Commit the changes to the path. + void commit() { + if( !(front.empty() && back.empty()) ) { + Container tmp; + tmp.reserve(front.size()+back.size()+P.length()); + tmp.insert(tmp.end(), front.rbegin(), front.rend()); + tmp.insert(tmp.end(), P.edges.begin(), P.edges.end()); + tmp.insert(tmp.end(), back.begin(), back.end()); + P.edges.swap(tmp); + front.clear(); + back.clear(); + } + } + + + ///Reserve storage for the builder in advance. + + ///If you know a reasonable upper bound of the number of the edges + ///to add to the front, using this function you can speed up the building. + + void reserveFront(size_t r) {front.reserve(r);} + + ///Reserve storage for the builder in advance. + + ///If you know a reasonable upper bound of the number of the edges + ///to add to the back, using this function you can speed up the building. + + void reserveBack(size_t r) {back.reserve(r);} + + private: + bool empty() { + return front.empty() && back.empty() && P.empty(); + } + + GraphNode source() const { + if( ! front.empty() ) + return P.gr->source(front[front.size()-1]); + else if( ! P.empty() ) + return P.gr->source(P.edges[0]); + else if( ! back.empty() ) + return P.gr->source(back[0]); + else + return INVALID; + } + GraphNode target() const { + if( ! back.empty() ) + return P.gr->target(back[back.size()-1]); + else if( ! P.empty() ) + return P.gr->target(P.edges[P.length()-1]); + else if( ! front.empty() ) + return P.gr->target(front[0]); + else + return INVALID; + } + + }; + + }; + + + ///@} + +} // namespace lemon + +#endif // LEMON_PATH_H