diff --git a/lemon/suurballe.h b/lemon/suurballe.h --- a/lemon/suurballe.h +++ b/lemon/suurballe.h @@ -33,29 +33,31 @@ /// \addtogroup shortest_path /// @{ - /// \brief Implementation of an algorithm for finding arc-disjoint - /// paths between two nodes having minimum total length. + /// \brief Algorithm for finding arc-disjoint paths between two nodes + /// having minimum total length. /// /// \ref lemon::Suurballe "Suurballe" implements an algorithm for /// finding arc-disjoint paths having minimum total length (cost) - /// from a given source node to a given target node in a directed - /// digraph. + /// from a given source node to a given target node in a digraph. /// /// In fact, this implementation is the specialization of the /// \ref CapacityScaling "successive shortest path" algorithm. /// - /// \tparam Digraph The directed digraph type the algorithm runs on. + /// \tparam Digraph The digraph type the algorithm runs on. + /// The default value is \c ListDigraph. /// \tparam LengthMap The type of the length (cost) map. + /// The default value is Digraph::ArcMap. /// /// \warning Length values should be \e non-negative \e integers. /// /// \note For finding node-disjoint paths this algorithm can be used /// with \ref SplitDigraphAdaptor. - /// - /// \author Attila Bernath and Peter Kovacs - - template < typename Digraph, +#ifdef DOXYGEN + template +#else + template < typename Digraph = ListDigraph, typename LengthMap = typename Digraph::template ArcMap > +#endif class Suurballe { TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); @@ -75,7 +77,7 @@ private: - /// \brief Special implementation of the \ref Dijkstra algorithm + /// \brief Special implementation of the Dijkstra algorithm /// for finding shortest paths in the residual network. /// /// \ref ResidualDijkstra is a special implementation of the @@ -90,7 +92,7 @@ private: - // The directed digraph the algorithm runs on + // The digraph the algorithm runs on const Digraph &_graph; // The main maps @@ -120,7 +122,7 @@ _graph(digraph), _flow(flow), _length(length), _potential(potential), _dist(digraph), _pred(pred), _s(s), _t(t) {} - /// \brief Runs the algorithm. Returns \c true if a path is found + /// \brief Run the algorithm. It returns \c true if a path is found /// from the source node to the target node. bool run() { HeapCrossRef heap_cross_ref(_graph, Heap::PRE_HEAP); @@ -129,7 +131,7 @@ _pred[_s] = INVALID; _proc_nodes.clear(); - // Processing nodes + // Process nodes while (!heap.empty() && heap.top() != _t) { Node u = heap.top(), v; Length d = heap.prio() + _potential[u], nd; @@ -137,7 +139,7 @@ heap.pop(); _proc_nodes.push_back(u); - // Traversing outgoing arcs + // Traverse outgoing arcs for (OutArcIt e(_graph, u); e != INVALID; ++e) { if (_flow[e] == 0) { v = _graph.target(e); @@ -159,7 +161,7 @@ } } - // Traversing incoming arcs + // Traverse incoming arcs for (InArcIt e(_graph, u); e != INVALID; ++e) { if (_flow[e] == 1) { v = _graph.source(e); @@ -183,7 +185,7 @@ } if (heap.empty()) return false; - // Updating potentials of processed nodes + // Update potentials of processed nodes Length t_dist = heap.prio(); for (int i = 0; i < int(_proc_nodes.size()); ++i) _potential[_proc_nodes[i]] += _dist[_proc_nodes[i]] - t_dist; @@ -194,7 +196,7 @@ private: - // The directed digraph the algorithm runs on + // The digraph the algorithm runs on const Digraph &_graph; // The length map const LengthMap &_length; @@ -227,7 +229,7 @@ /// /// Constructor. /// - /// \param digraph The directed digraph the algorithm runs on. + /// \param digraph The digraph the algorithm runs on. /// \param length The length (cost) values of the arcs. /// \param s The source node. /// \param t The target node. @@ -245,9 +247,9 @@ delete _dijkstra; } - /// \brief Sets the flow map. + /// \brief Set the flow map. /// - /// Sets the flow map. + /// This function sets the flow map. /// /// The found flow contains only 0 and 1 values. It is the union of /// the found arc-disjoint paths. @@ -262,9 +264,9 @@ return *this; } - /// \brief Sets the potential map. + /// \brief Set the potential map. /// - /// Sets the potential map. + /// This function sets the potential map. /// /// The potentials provide the dual solution of the underlying /// minimum cost flow problem. @@ -288,14 +290,14 @@ /// @{ - /// \brief Runs the algorithm. + /// \brief Run the algorithm. /// - /// Runs the algorithm. + /// This function runs the algorithm. /// /// \param k The number of paths to be found. /// - /// \return \c k if there are at least \c k arc-disjoint paths - /// from \c s to \c t. Otherwise it returns the number of + /// \return \c k if there are at least \c k arc-disjoint paths from + /// \c s to \c t in the digraph. Otherwise it returns the number of /// arc-disjoint paths found. /// /// \note Apart from the return value, s.run(k) is just a @@ -312,11 +314,11 @@ return _path_num; } - /// \brief Initializes the algorithm. + /// \brief Initialize the algorithm. /// - /// Initializes the algorithm. + /// This function initializes the algorithm. void init() { - // Initializing maps + // Initialize maps if (!_flow) { _flow = new FlowMap(_graph); _local_flow = true; @@ -333,27 +335,27 @@ _source, _target ); } - /// \brief Executes the successive shortest path algorithm to find + /// \brief Execute the successive shortest path algorithm to find /// an optimal flow. /// - /// Executes the successive shortest path algorithm to find a - /// minimum cost flow, which is the union of \c k or less + /// This function executes the successive shortest path algorithm to + /// find a minimum cost flow, which is the union of \c k or less /// arc-disjoint paths. /// - /// \return \c k if there are at least \c k arc-disjoint paths - /// from \c s to \c t. Otherwise it returns the number of + /// \return \c k if there are at least \c k arc-disjoint paths from + /// \c s to \c t in the digraph. Otherwise it returns the number of /// arc-disjoint paths found. /// /// \pre \ref init() must be called before using this function. int findFlow(int k = 2) { - // Finding shortest paths + // Find shortest paths _path_num = 0; while (_path_num < k) { - // Running Dijkstra + // Run Dijkstra if (!_dijkstra->run()) break; ++_path_num; - // Setting the flow along the found shortest path + // Set the flow along the found shortest path Node u = _target; Arc e; while ((e = _pred[u]) != INVALID) { @@ -369,17 +371,17 @@ return _path_num; } - /// \brief Computes the paths from the flow. + /// \brief Compute the paths from the flow. /// - /// Computes the paths from the flow. + /// This function computes the paths from the flow. /// /// \pre \ref init() and \ref findFlow() must be called before using /// this function. void findPaths() { - // Creating the residual flow map (the union of the paths not - // found so far) + // Create the residual flow map (the union of the paths not found + // so far) FlowMap res_flow(_graph); - for(ArcIt a(_graph);a!=INVALID;++a) res_flow[a]=(*_flow)[a]; + for(ArcIt a(_graph); a != INVALID; ++a) res_flow[a] = (*_flow)[a]; paths.clear(); paths.resize(_path_num); @@ -398,66 +400,66 @@ /// @} /// \name Query Functions - /// The result of the algorithm can be obtained using these + /// The results of the algorithm can be obtained using these /// functions. /// \n The algorithm should be executed before using them. /// @{ - /// \brief Returns a const reference to the arc map storing the + /// \brief Return a const reference to the arc map storing the /// found flow. /// - /// Returns a const reference to the arc map storing the flow that - /// is the union of the found arc-disjoint paths. + /// This function returns a const reference to the arc map storing + /// the flow that is the union of the found arc-disjoint paths. /// - /// \pre \ref run() or findFlow() must be called before using this - /// function. + /// \pre \ref run() or \ref findFlow() must be called before using + /// this function. const FlowMap& flowMap() const { return *_flow; } - /// \brief Returns a const reference to the node map storing the + /// \brief Return a const reference to the node map storing the /// found potentials (the dual solution). /// - /// Returns a const reference to the node map storing the found - /// potentials that provide the dual solution of the underlying - /// minimum cost flow problem. + /// This function returns a const reference to the node map storing + /// the found potentials that provide the dual solution of the + /// underlying minimum cost flow problem. /// - /// \pre \ref run() or findFlow() must be called before using this - /// function. + /// \pre \ref run() or \ref findFlow() must be called before using + /// this function. const PotentialMap& potentialMap() const { return *_potential; } - /// \brief Returns the flow on the given arc. + /// \brief Return the flow on the given arc. /// - /// Returns the flow on the given arc. + /// This function returns the flow on the given arc. /// It is \c 1 if the arc is involved in one of the found paths, /// otherwise it is \c 0. /// - /// \pre \ref run() or findFlow() must be called before using this - /// function. + /// \pre \ref run() or \ref findFlow() must be called before using + /// this function. int flow(const Arc& arc) const { return (*_flow)[arc]; } - /// \brief Returns the potential of the given node. + /// \brief Return the potential of the given node. /// - /// Returns the potential of the given node. + /// This function returns the potential of the given node. /// - /// \pre \ref run() or findFlow() must be called before using this - /// function. + /// \pre \ref run() or \ref findFlow() must be called before using + /// this function. Length potential(const Node& node) const { return (*_potential)[node]; } - /// \brief Returns the total length (cost) of the found paths (flow). + /// \brief Return the total length (cost) of the found paths (flow). /// - /// Returns the total length (cost) of the found paths (flow). - /// The complexity of the function is \f$ O(e) \f$. + /// This function returns the total length (cost) of the found paths + /// (flow). The complexity of the function is \f$ O(e) \f$. /// - /// \pre \ref run() or findFlow() must be called before using this - /// function. + /// \pre \ref run() or \ref findFlow() must be called before using + /// this function. Length totalLength() const { Length c = 0; for (ArcIt e(_graph); e != INVALID; ++e) @@ -465,25 +467,25 @@ return c; } - /// \brief Returns the number of the found paths. + /// \brief Return the number of the found paths. /// - /// Returns the number of the found paths. + /// This function returns the number of the found paths. /// - /// \pre \ref run() or findFlow() must be called before using this - /// function. + /// \pre \ref run() or \ref findFlow() must be called before using + /// this function. int pathNum() const { return _path_num; } - /// \brief Returns a const reference to the specified path. + /// \brief Return a const reference to the specified path. /// - /// Returns a const reference to the specified path. + /// This function returns a const reference to the specified path. /// /// \param i The function returns the \c i-th path. /// \c i must be between \c 0 and %pathNum()-1. /// - /// \pre \ref run() or findPaths() must be called before using this - /// function. + /// \pre \ref run() or \ref findPaths() must be called before using + /// this function. Path path(int i) const { return paths[i]; } diff --git a/test/suurballe_test.cc b/test/suurballe_test.cc --- a/test/suurballe_test.cc +++ b/test/suurballe_test.cc @@ -28,7 +28,7 @@ using namespace lemon; -// Checks the feasibility of the flow +// Check the feasibility of the flow template bool checkFlow( const Digraph& gr, const FlowMap& flow, typename Digraph::Node s, typename Digraph::Node t, @@ -52,13 +52,13 @@ return true; } -// Checks the optimalitiy of the flow +// Check the optimalitiy of the flow template < typename Digraph, typename CostMap, typename FlowMap, typename PotentialMap > bool checkOptimality( const Digraph& gr, const CostMap& cost, const FlowMap& flow, const PotentialMap& pi ) { - // Checking the Complementary Slackness optimality condition + // Check the "Complementary Slackness" optimality condition TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); bool opt = true; for (ArcIt e(gr); e != INVALID; ++e) { @@ -71,12 +71,12 @@ return opt; } -// Checks a path -template < typename Digraph, typename Path > +// Check a path +template bool checkPath( const Digraph& gr, const Path& path, typename Digraph::Node s, typename Digraph::Node t) { - // Checking the Complementary Slackness optimality condition + // Check the "Complementary Slackness" optimality condition TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); Node n = s; for (int i = 0; i < path.length(); ++i) { @@ -91,7 +91,7 @@ { DIGRAPH_TYPEDEFS(ListDigraph); - // Reading the test digraph + // Read the test digraph ListDigraph digraph; ListDigraph::ArcMap length(digraph); Node source, target; @@ -111,7 +111,7 @@ run(); input.close(); - // Finding 2 paths + // Find 2 paths { Suurballe suurballe(digraph, length, source, target); check(suurballe.run(2) == 2, "Wrong number of paths"); @@ -126,7 +126,7 @@ "Wrong path"); } - // Finding 3 paths + // Find 3 paths { Suurballe suurballe(digraph, length, source, target); check(suurballe.run(3) == 3, "Wrong number of paths"); @@ -141,7 +141,7 @@ "Wrong path"); } - // Finding 5 paths (only 3 can be found) + // Find 5 paths (only 3 can be found) { Suurballe suurballe(digraph, length, source, target); check(suurballe.run(5) == 3, "Wrong number of paths");