deba@2335: /* -*- C++ -*-
deba@2335:  *
deba@2335:  * This file is a part of LEMON, a generic C++ optimization library
deba@2335:  *
alpar@2391:  * Copyright (C) 2003-2007
deba@2335:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
deba@2335:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
deba@2335:  *
deba@2335:  * Permission to use, modify and distribute this software is granted
deba@2335:  * provided that this copyright notice appears in all copies. For
deba@2335:  * precise terms see the accompanying LICENSE file.
deba@2335:  *
deba@2335:  * This software is provided "AS IS" with no warranty of any kind,
deba@2335:  * express or implied, and with no claim as to its suitability for any
deba@2335:  * purpose.
deba@2335:  *
deba@2335:  */
deba@2335: 
deba@2335: ///\ingroup paths
deba@2335: ///\file
deba@2335: ///\brief Classes for representing paths in graphs.
deba@2335: ///
deba@2335: 
deba@2335: #ifndef LEMON_PATH_UTILS_H
deba@2335: #define LEMON_PATH_UTILS_H
deba@2335: 
deba@2335: #include <lemon/concepts/path.h>
deba@2335: 
deba@2335: namespace lemon {
deba@2335: 
deba@2335:   namespace _path_bits {
deba@2335: 
deba@2335:     template <typename Path, typename Enable = void>
deba@2335:     struct RevTagIndicator {
deba@2335:       static const bool value = false;
deba@2335:     };
deba@2335: 
deba@2335:     template <typename Graph>
deba@2335:     struct RevTagIndicator<
deba@2335:       Graph, 
deba@2335:       typename enable_if<typename Graph::RevTag, void>::type
deba@2335:     > {
deba@2335:       static const bool value = true;
deba@2335:     };
deba@2335: 
deba@2335:     template <typename Target, typename Source,
deba@2335:               typename BuildEnable = void, typename RevEnable = void>
deba@2335:     struct PathCopySelector {
deba@2335:       static void copy(Target& target, const Source& source) {
deba@2357:         target.clear();
deba@2335:         for (typename Source::EdgeIt it(source); it != INVALID; ++it) {
deba@2335:           target.addBack(it);
deba@2335:         }
deba@2335:       }
deba@2335:     };
deba@2335: 
deba@2335:     template <typename Target, typename Source, typename BuildEnable>
deba@2335:     struct PathCopySelector<
deba@2335:       Target, Source, BuildEnable, 
deba@2335:       typename enable_if<typename Source::RevPathTag, void>::type> {
deba@2335:       static void copy(Target& target, const Source& source) {
deba@2357:         target.clear();
deba@2357:         for (typename Source::RevEdgeIt it(source); it != INVALID; ++it) {
deba@2335:           target.addFront(it);
deba@2335:         }
deba@2335:       }
deba@2335:     };
deba@2335: 
deba@2335:     template <typename Target, typename Source, typename RevEnable>
deba@2335:     struct PathCopySelector<
deba@2335:       Target, Source, 
deba@2335:       typename enable_if<typename Target::BuildTag, void>::type, RevEnable> {
deba@2335:       static void copy(Target& target, const Source& source) {
deba@2335:         target.clear();
deba@2335:         target.build(source);
deba@2335:       }
deba@2335:     };
deba@2335: 
deba@2335:     template <typename Target, typename Source>
deba@2335:     struct PathCopySelector<
deba@2335:       Target, Source, 
deba@2335:       typename enable_if<typename Target::BuildTag, void>::type,
deba@2335:       typename enable_if<typename Source::RevPathTag, void>::type> {
deba@2335:       static void copy(Target& target, const Source& source) {
deba@2335:         target.clear();
deba@2335:         target.buildRev(source);
deba@2335:       }
deba@2335:     };
deba@2335: 
deba@2335:   }
deba@2335: 
deba@2335: 
deba@2335:   /// \brief Make of copy of a path.
deba@2335:   ///
deba@2335:   ///  Make of copy of a path.
deba@2335:   template <typename Target, typename Source>
deba@2335:   void copyPath(Target& target, const Source& source) {
deba@2335:     checkConcept<concepts::PathDumper<typename Source::Graph>, Source>();
deba@2335:     _path_bits::PathCopySelector<Target, Source>::copy(target, source);
deba@2335:   }
deba@2335: 
deba@2335:   /// \brief Checks the path's consistency.
deba@2335:   ///
deba@2335:   /// Checks that each edge's target is the next's source. 
alpar@2350:   /// 
deba@2335:   template <typename Graph, typename Path>
deba@2335:   bool checkPath(const Graph& graph, const Path& path) {
deba@2335:     typename Path::EdgeIt it(path);
deba@2335:     if (it == INVALID) return true;
deba@2335:     typename Graph::Node node = graph.target(it);
deba@2335:     ++it;
deba@2335:     while (it != INVALID) {
deba@2335:       if (graph.source(it) != node) return false;
deba@2335:       node = graph.target(it);
deba@2335:       ++it;
deba@2335:     }
deba@2335:     return true;
deba@2335:   }
deba@2335: 
deba@2335:   /// \brief Gives back the source of the path
deba@2335:   ///
deba@2335:   /// Gives back the source of the path.
deba@2335:   template <typename Graph, typename Path>
deba@2335:   typename Graph::Node pathSource(const Graph& graph, const Path& path) {
deba@2335:     return graph.source(path.front());
deba@2335:   }
deba@2335: 
deba@2335:   /// \brief Gives back the target of the path
deba@2335:   ///
deba@2335:   /// Gives back the target of the path.
deba@2335:   template <typename Graph, typename Path>
deba@2335:   typename Graph::Node pathTarget(const Graph& graph, const Path& path) {
deba@2335:     return graph.target(path.back());
deba@2335:   }
deba@2335: }
deba@2335: 
deba@2335: #endif