[1698] | 1 | /* -*- C++ -*- |
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| 2 | * lemon/topology.h - Part of LEMON, a generic C++ optimization library |
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| 3 | * |
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| 4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 5 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 6 | * |
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| 7 | * Permission to use, modify and distribute this software is granted |
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| 8 | * provided that this copyright notice appears in all copies. For |
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| 9 | * precise terms see the accompanying LICENSE file. |
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| 10 | * |
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| 11 | * This software is provided "AS IS" with no warranty of any kind, |
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| 12 | * express or implied, and with no claim as to its suitability for any |
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| 13 | * purpose. |
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| 14 | * |
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| 15 | */ |
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| 16 | |
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| 17 | #ifndef LEMON_TOPOLOGY_H |
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| 18 | #define LEMON_TOPOLOGY_H |
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| 19 | |
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| 20 | #include <lemon/dfs.h> |
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[1740] | 21 | #include <lemon/bfs.h> |
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[1698] | 22 | #include <lemon/graph_utils.h> |
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| 23 | |
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| 24 | #include <lemon/concept/graph.h> |
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| 25 | #include <lemon/concept/undir_graph.h> |
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| 26 | #include <lemon/concept_check.h> |
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| 27 | |
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| 28 | /// \ingroup flowalgs |
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| 29 | /// \file |
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| 30 | /// \brief Topology related algorithms |
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| 31 | /// |
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| 32 | /// Topology related algorithms |
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[1739] | 33 | ///\todo Place the file contents is the module tree. |
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[1698] | 34 | |
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| 35 | namespace lemon { |
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| 36 | |
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| 37 | namespace _topology_bits { |
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| 38 | |
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| 39 | template <typename NodeMap> |
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| 40 | class BackCounterMap { |
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| 41 | public: |
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| 42 | BackCounterMap(NodeMap& _nodeMap, int _counter) |
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| 43 | : nodeMap(_nodeMap), counter(_counter) {} |
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| 44 | |
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| 45 | void set(typename NodeMap::Key key, bool val) { |
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| 46 | if (val) { |
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| 47 | nodeMap.set(key, --counter); |
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| 48 | } else { |
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| 49 | nodeMap.set(key, -1); |
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| 50 | } |
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| 51 | } |
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| 52 | |
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| 53 | bool operator[](typename NodeMap::Key key) const { |
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| 54 | return nodeMap[key] != -1; |
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| 55 | } |
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| 56 | |
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| 57 | private: |
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| 58 | NodeMap& nodeMap; |
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| 59 | int counter; |
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| 60 | }; |
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| 61 | } |
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| 62 | |
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| 63 | // \todo Its to special output // ReadWriteMap |
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| 64 | template <typename Graph, typename NodeMap> |
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| 65 | bool topological_sort(const Graph& graph, NodeMap& nodeMap) { |
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| 66 | using namespace _topology_bits; |
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| 67 | |
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| 68 | checkConcept<concept::StaticGraph, Graph>(); |
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| 69 | checkConcept<concept::ReadWriteMap<typename Graph::Node, int>, NodeMap>(); |
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| 70 | |
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| 71 | typedef typename Graph::Node Node; |
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| 72 | typedef typename Graph::NodeIt NodeIt; |
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| 73 | typedef typename Graph::Edge Edge; |
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| 74 | |
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| 75 | typedef BackCounterMap<NodeMap> ProcessedMap; |
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| 76 | |
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| 77 | typename Dfs<Graph>::template DefProcessedMap<ProcessedMap>:: |
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[1709] | 78 | Create dfs(graph); |
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[1698] | 79 | |
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| 80 | ProcessedMap processed(nodeMap, countNodes(graph)); |
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| 81 | |
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| 82 | dfs.processedMap(processed); |
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| 83 | dfs.init(); |
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| 84 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 85 | if (!dfs.reached(it)) { |
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| 86 | dfs.addSource(it); |
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| 87 | while (!dfs.emptyQueue()) { |
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| 88 | Edge edge = dfs.nextEdge(); |
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| 89 | Node target = graph.target(edge); |
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| 90 | if (dfs.reached(target) && !processed[target]) { |
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| 91 | return false; |
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| 92 | } |
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| 93 | dfs.processNextEdge(); |
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| 94 | } |
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| 95 | } |
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| 96 | } |
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| 97 | return true; |
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| 98 | } |
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| 99 | |
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| 100 | /// \brief Check that the given graph is a DAG. |
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| 101 | /// |
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| 102 | /// Check that the given graph is a DAG. The DAG is |
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| 103 | /// an Directed Acyclic Graph. |
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| 104 | template <typename Graph> |
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| 105 | bool dag(const Graph& graph) { |
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| 106 | |
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| 107 | checkConcept<concept::StaticGraph, Graph>(); |
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| 108 | |
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| 109 | typedef typename Graph::Node Node; |
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| 110 | typedef typename Graph::NodeIt NodeIt; |
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| 111 | typedef typename Graph::Edge Edge; |
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| 112 | |
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| 113 | typedef typename Graph::template NodeMap<bool> ProcessedMap; |
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| 114 | |
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| 115 | typename Dfs<Graph>::template DefProcessedMap<ProcessedMap>:: |
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[1709] | 116 | Create dfs(graph); |
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[1698] | 117 | |
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| 118 | ProcessedMap processed(graph); |
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| 119 | dfs.processedMap(processed); |
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| 120 | |
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| 121 | dfs.init(); |
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| 122 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 123 | if (!dfs.reached(it)) { |
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| 124 | dfs.addSource(it); |
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| 125 | while (!dfs.emptyQueue()) { |
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| 126 | Edge edge = dfs.nextEdge(); |
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| 127 | Node target = graph.target(edge); |
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| 128 | if (dfs.reached(target) && !processed[target]) { |
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| 129 | return false; |
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| 130 | } |
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| 131 | dfs.processNextEdge(); |
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| 132 | } |
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| 133 | } |
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| 134 | } |
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| 135 | return true; |
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| 136 | } |
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| 137 | |
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| 138 | // UndirGraph algorithms |
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| 139 | |
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| 140 | /// \brief Check that the given undirected graph is connected. |
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| 141 | /// |
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| 142 | /// Check that the given undirected graph connected. |
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| 143 | template <typename UndirGraph> |
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| 144 | bool connected(const UndirGraph& graph) { |
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| 145 | checkConcept<concept::UndirGraph, UndirGraph>(); |
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| 146 | typedef typename UndirGraph::NodeIt NodeIt; |
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| 147 | if (NodeIt(graph) == INVALID) return false; |
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| 148 | Dfs<UndirGraph> dfs(graph); |
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| 149 | dfs.run(NodeIt(graph)); |
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| 150 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 151 | if (!dfs.reached(it)) { |
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| 152 | return false; |
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| 153 | } |
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| 154 | } |
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| 155 | return true; |
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| 156 | } |
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| 157 | |
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| 158 | /// \brief Check that the given undirected graph is acyclic. |
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| 159 | /// |
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| 160 | /// Check that the given undirected graph acyclic. |
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| 161 | template <typename UndirGraph> |
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| 162 | bool acyclic(const UndirGraph& graph) { |
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| 163 | checkConcept<concept::UndirGraph, UndirGraph>(); |
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| 164 | typedef typename UndirGraph::Node Node; |
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| 165 | typedef typename UndirGraph::NodeIt NodeIt; |
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| 166 | typedef typename UndirGraph::Edge Edge; |
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| 167 | Dfs<UndirGraph> dfs(graph); |
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| 168 | dfs.init(); |
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| 169 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 170 | if (!dfs.reached(it)) { |
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| 171 | dfs.addSource(it); |
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| 172 | while (!dfs.emptyQueue()) { |
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| 173 | Edge edge = dfs.nextEdge(); |
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| 174 | Node source = graph.source(edge); |
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| 175 | Node target = graph.target(edge); |
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| 176 | if (dfs.reached(target) && |
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| 177 | dfs.pred(source) != graph.oppositeEdge(edge)) { |
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| 178 | return false; |
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| 179 | } |
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| 180 | dfs.processNextEdge(); |
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| 181 | } |
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| 182 | } |
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| 183 | } |
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| 184 | return true; |
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| 185 | } |
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| 186 | |
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| 187 | /// \brief Check that the given undirected graph is tree. |
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| 188 | /// |
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| 189 | /// Check that the given undirected graph is tree. |
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| 190 | template <typename UndirGraph> |
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| 191 | bool tree(const UndirGraph& graph) { |
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| 192 | checkConcept<concept::UndirGraph, UndirGraph>(); |
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| 193 | typedef typename UndirGraph::Node Node; |
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| 194 | typedef typename UndirGraph::NodeIt NodeIt; |
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| 195 | typedef typename UndirGraph::Edge Edge; |
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| 196 | if (NodeIt(graph) == INVALID) return false; |
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| 197 | Dfs<UndirGraph> dfs(graph); |
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| 198 | dfs.init(); |
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| 199 | dfs.addSource(NodeIt(graph)); |
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| 200 | while (!dfs.emptyQueue()) { |
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| 201 | Edge edge = dfs.nextEdge(); |
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| 202 | Node source = graph.source(edge); |
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| 203 | Node target = graph.target(edge); |
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| 204 | if (dfs.reached(target) && |
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| 205 | dfs.pred(source) != graph.oppositeEdge(edge)) { |
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| 206 | return false; |
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| 207 | } |
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| 208 | dfs.processNextEdge(); |
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| 209 | } |
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| 210 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 211 | if (!dfs.reached(it)) { |
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| 212 | return false; |
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| 213 | } |
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| 214 | } |
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| 215 | return true; |
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| 216 | } |
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| 217 | |
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[1739] | 218 | ///Count the number of connected components of an undirected graph |
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| 219 | |
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| 220 | ///Count the number of connected components of an undirected graph |
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| 221 | /// |
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| 222 | ///\param g The graph. In must be undirected. |
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| 223 | ///\return The number of components |
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[1740] | 224 | template <class UndirGraph> |
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| 225 | int countConnectedComponents(const UndirGraph &g) { |
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| 226 | checkConcept<concept::UndirGraph, UndirGraph>(); |
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| 227 | int c = 0; |
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| 228 | Bfs<UndirGraph> bfs(g); |
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[1739] | 229 | bfs.init(); |
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[1740] | 230 | for(typename UndirGraph::NodeIt n(g); n != INVALID; ++n) { |
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[1739] | 231 | if(!bfs.reached(n)) { |
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| 232 | bfs.addSource(n); |
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| 233 | bfs.start(); |
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[1740] | 234 | ++c; |
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[1739] | 235 | } |
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[1740] | 236 | } |
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[1739] | 237 | return c; |
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| 238 | } |
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| 239 | |
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| 240 | |
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| 241 | ///Find the connected components of an undirected graph |
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| 242 | |
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| 243 | ///Find the connected components of an undirected graph |
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| 244 | /// |
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| 245 | ///\param g The graph. In must be undirected. |
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| 246 | ///\retval comp A writable node map. The values will be set from 0 to |
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| 247 | ///the number of the connected components minus one. Each values of the map |
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| 248 | ///will be set exactly once, the values of a certain component will be |
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| 249 | ///set continuously. |
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| 250 | ///\return The number of components |
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| 251 | ///\todo Test required |
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[1740] | 252 | template <class UndirGraph, class IntNodeMap> |
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| 253 | int connectedComponents(const UndirGraph &g, IntNodeMap &comp) { |
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| 254 | checkConcept<concept::UndirGraph, UndirGraph>(); |
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| 255 | checkConcept<concept::WriteMap<typename UndirGraph::Node, int>, |
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| 256 | IntNodeMap>(); |
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| 257 | int c = 0; |
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| 258 | Bfs<UndirGraph> bfs(g); |
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[1739] | 259 | bfs.init(); |
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[1740] | 260 | for(typename UndirGraph::NodeIt n(g); n != INVALID; ++n) { |
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[1739] | 261 | if(!bfs.reached(n)) { |
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| 262 | bfs.addSource(n); |
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[1740] | 263 | while (!bfs.emptyQueue()) { |
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| 264 | comp[bfs.nextNode()] = c; |
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| 265 | bfs.processNextNode(); |
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| 266 | } |
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| 267 | ++c; |
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[1739] | 268 | } |
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[1740] | 269 | } |
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[1739] | 270 | return c; |
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| 271 | } |
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[1698] | 272 | |
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[1740] | 273 | namespace _components_bits { |
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| 274 | |
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| 275 | template <typename Key, typename IntMap> |
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| 276 | struct FillWriteMap : public MapBase<Key, bool> { |
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| 277 | public: |
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| 278 | FillWriteMap(IntMap& _map, int& _comp) |
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| 279 | : map(_map), comp(_comp) {} |
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| 280 | void set(Key key, bool value) { |
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| 281 | if (value) { map.set(key, comp); } |
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| 282 | } |
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| 283 | private: |
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| 284 | IntMap& map; |
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| 285 | int& comp; |
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| 286 | }; |
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| 287 | |
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| 288 | template <typename Key, typename Container = std::vector<Key> > |
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| 289 | struct BackInserterWriteMap : public MapBase<Key, bool> { |
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| 290 | public: |
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| 291 | BackInserterWriteMap(Container& _container) |
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| 292 | : container(_container) {} |
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| 293 | void set(Key key, bool value) { |
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| 294 | if (value) { container.push_back(key); } |
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| 295 | } |
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| 296 | private: |
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| 297 | Container& container; |
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| 298 | }; |
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| 299 | |
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| 300 | } |
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| 301 | |
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| 302 | /// \brief Count the strongly connected components of a directed graph |
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| 303 | /// |
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| 304 | /// Count the strongly connected components of a directed graph |
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| 305 | /// |
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| 306 | /// \param g The graph. |
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| 307 | /// \return The number of components |
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| 308 | template <typename Graph> |
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| 309 | int countStronglyConnectedComponents(const Graph& graph) { |
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| 310 | checkConcept<concept::StaticGraph, Graph>(); |
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| 311 | |
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| 312 | using namespace _components_bits; |
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| 313 | |
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| 314 | typedef typename Graph::Node Node; |
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| 315 | typedef typename Graph::Edge Edge; |
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| 316 | typedef typename Graph::NodeIt NodeIt; |
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| 317 | typedef typename Graph::EdgeIt EdgeIt; |
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| 318 | |
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| 319 | |
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| 320 | typename Dfs<Graph>:: |
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| 321 | template DefProcessedMap<BackInserterWriteMap<Node> >:: |
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| 322 | Create dfs(graph); |
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| 323 | |
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| 324 | std::vector<Node> nodes; |
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| 325 | BackInserterWriteMap<Node> processed(nodes); |
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| 326 | dfs.processedMap(processed); |
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| 327 | |
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| 328 | dfs.init(); |
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| 329 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 330 | if (!dfs.reached(it)) { |
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| 331 | dfs.addSource(it); |
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| 332 | dfs.start(); |
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| 333 | } |
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| 334 | } |
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| 335 | |
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| 336 | typedef RevGraphAdaptor<const Graph> RGraph; |
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| 337 | |
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| 338 | RGraph rgraph(graph); |
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| 339 | |
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| 340 | Dfs<RGraph> rdfs(rgraph); |
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| 341 | |
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| 342 | int num = 0; |
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| 343 | |
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| 344 | rdfs.init(); |
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| 345 | for (typename std::vector<Node>::reverse_iterator |
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| 346 | it = nodes.rbegin(); it != nodes.rend(); ++it) { |
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| 347 | if (!rdfs.reached(*it)) { |
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| 348 | rdfs.addSource(*it); |
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| 349 | rdfs.start(); |
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| 350 | ++num; |
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| 351 | } |
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| 352 | } |
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| 353 | return num; |
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| 354 | } |
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| 355 | |
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| 356 | /// \brief Find the strongly connected components of a directed graph |
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| 357 | /// |
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| 358 | /// Find the strongly connected components of a directed graph |
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| 359 | /// |
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| 360 | /// \param g The graph. |
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| 361 | /// \retval comp A writable node map. The values will be set from 0 to |
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| 362 | /// the number of the strongly connected components minus one. Each values |
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| 363 | /// of the map will be set exactly once, the values of a certain component |
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| 364 | /// will be set continuously. |
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| 365 | /// \return The number of components |
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| 366 | template <typename Graph, typename IntNodeMap> |
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| 367 | int stronglyConnectedComponents(const Graph& graph, IntNodeMap& comp) { |
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| 368 | checkConcept<concept::StaticGraph, Graph>(); |
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| 369 | checkConcept<concept::WriteMap<typename Graph::Node, int>, IntNodeMap>(); |
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| 370 | |
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| 371 | using namespace _components_bits; |
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| 372 | |
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| 373 | typedef typename Graph::Node Node; |
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| 374 | typedef typename Graph::Edge Edge; |
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| 375 | typedef typename Graph::NodeIt NodeIt; |
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| 376 | typedef typename Graph::EdgeIt EdgeIt; |
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| 377 | |
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| 378 | |
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| 379 | typename Dfs<Graph>:: |
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| 380 | template DefProcessedMap<BackInserterWriteMap<Node> >:: |
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| 381 | Create dfs(graph); |
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| 382 | |
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| 383 | std::vector<Node> nodes; |
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| 384 | BackInserterWriteMap<Node> processed(nodes); |
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| 385 | dfs.processedMap(processed); |
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| 386 | |
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| 387 | dfs.init(); |
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| 388 | for (NodeIt it(graph); it != INVALID; ++it) { |
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| 389 | if (!dfs.reached(it)) { |
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| 390 | dfs.addSource(it); |
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| 391 | dfs.start(); |
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| 392 | } |
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| 393 | } |
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| 394 | |
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| 395 | typedef RevGraphAdaptor<const Graph> RGraph; |
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| 396 | |
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| 397 | RGraph rgraph(graph); |
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| 398 | |
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| 399 | typename Dfs<RGraph>:: |
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| 400 | template DefProcessedMap<FillWriteMap<Node, IntNodeMap> >:: |
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| 401 | Create rdfs(rgraph); |
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| 402 | |
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| 403 | int num = 0; |
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| 404 | FillWriteMap<Node, IntNodeMap> rprocessed(comp, num); |
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| 405 | rdfs.processedMap(rprocessed); |
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| 406 | |
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| 407 | rdfs.init(); |
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| 408 | for (typename std::vector<Node>::reverse_iterator |
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| 409 | it = nodes.rbegin(); it != nodes.rend(); ++it) { |
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| 410 | if (!rdfs.reached(*it)) { |
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| 411 | rdfs.addSource(*it); |
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| 412 | rdfs.start(); |
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| 413 | ++num; |
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| 414 | } |
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| 415 | } |
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| 416 | return num; |
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| 417 | } |
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| 418 | |
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[1698] | 419 | } //namespace lemon |
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| 420 | |
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| 421 | #endif //LEMON_TOPOLOGY_H |
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