[2480] | 1 | /* -*- C++ -*- |
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| 2 | * |
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| 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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[2553] | 5 | * Copyright (C) 2003-2008 |
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[2480] | 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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[2553] | 18 | |
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[2480] | 19 | #ifndef LEMON_PLANARITY_H |
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| 20 | #define LEMON_PLANARITY_H |
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| 21 | |
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[2499] | 22 | /// \ingroup planar |
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[2480] | 23 | /// \file |
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[2508] | 24 | /// \brief Planarity checking, embedding, drawing and coloring |
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[2480] | 25 | |
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| 26 | #include <vector> |
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| 27 | #include <list> |
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| 28 | |
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| 29 | #include <lemon/dfs.h> |
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[2508] | 30 | #include <lemon/bfs.h> |
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[2480] | 31 | #include <lemon/radix_sort.h> |
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| 32 | #include <lemon/maps.h> |
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| 33 | #include <lemon/path.h> |
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[2499] | 34 | #include <lemon/iterable_maps.h> |
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| 35 | #include <lemon/edge_set.h> |
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[2508] | 36 | #include <lemon/bucket_heap.h> |
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| 37 | #include <lemon/ugraph_adaptor.h> |
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| 38 | #include <lemon/color.h> |
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[2480] | 39 | |
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| 40 | |
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| 41 | namespace lemon { |
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| 42 | |
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| 43 | namespace _planarity_bits { |
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| 44 | |
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| 45 | template <typename UGraph> |
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| 46 | struct PlanarityVisitor : DfsVisitor<UGraph> { |
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| 47 | |
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| 48 | typedef typename UGraph::Node Node; |
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| 49 | typedef typename UGraph::Edge Edge; |
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| 50 | |
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| 51 | typedef typename UGraph::template NodeMap<Edge> PredMap; |
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| 52 | |
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| 53 | typedef typename UGraph::template UEdgeMap<bool> TreeMap; |
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| 54 | |
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| 55 | typedef typename UGraph::template NodeMap<int> OrderMap; |
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| 56 | typedef std::vector<Node> OrderList; |
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| 57 | |
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| 58 | typedef typename UGraph::template NodeMap<int> LowMap; |
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| 59 | typedef typename UGraph::template NodeMap<int> AncestorMap; |
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| 60 | |
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| 61 | PlanarityVisitor(const UGraph& ugraph, |
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| 62 | PredMap& pred_map, TreeMap& tree_map, |
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| 63 | OrderMap& order_map, OrderList& order_list, |
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| 64 | AncestorMap& ancestor_map, LowMap& low_map) |
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| 65 | : _ugraph(ugraph), _pred_map(pred_map), _tree_map(tree_map), |
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| 66 | _order_map(order_map), _order_list(order_list), |
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| 67 | _ancestor_map(ancestor_map), _low_map(low_map) {} |
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| 68 | |
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| 69 | void reach(const Node& node) { |
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| 70 | _order_map[node] = _order_list.size(); |
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| 71 | _low_map[node] = _order_list.size(); |
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| 72 | _ancestor_map[node] = _order_list.size(); |
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| 73 | _order_list.push_back(node); |
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| 74 | } |
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| 75 | |
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| 76 | void discover(const Edge& edge) { |
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| 77 | Node source = _ugraph.source(edge); |
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| 78 | Node target = _ugraph.target(edge); |
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| 79 | |
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| 80 | _tree_map[edge] = true; |
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| 81 | _pred_map[target] = edge; |
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| 82 | } |
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| 83 | |
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| 84 | void examine(const Edge& edge) { |
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| 85 | Node source = _ugraph.source(edge); |
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| 86 | Node target = _ugraph.target(edge); |
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| 87 | |
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| 88 | if (_order_map[target] < _order_map[source] && !_tree_map[edge]) { |
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| 89 | if (_low_map[source] > _order_map[target]) { |
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| 90 | _low_map[source] = _order_map[target]; |
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| 91 | } |
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| 92 | if (_ancestor_map[source] > _order_map[target]) { |
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| 93 | _ancestor_map[source] = _order_map[target]; |
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| 94 | } |
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| 95 | } |
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| 96 | } |
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| 97 | |
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| 98 | void backtrack(const Edge& edge) { |
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| 99 | Node source = _ugraph.source(edge); |
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| 100 | Node target = _ugraph.target(edge); |
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| 101 | |
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| 102 | if (_low_map[source] > _low_map[target]) { |
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| 103 | _low_map[source] = _low_map[target]; |
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| 104 | } |
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| 105 | } |
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| 106 | |
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| 107 | const UGraph& _ugraph; |
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| 108 | PredMap& _pred_map; |
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| 109 | TreeMap& _tree_map; |
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| 110 | OrderMap& _order_map; |
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| 111 | OrderList& _order_list; |
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| 112 | AncestorMap& _ancestor_map; |
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| 113 | LowMap& _low_map; |
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| 114 | }; |
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| 115 | |
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| 116 | template <typename UGraph, bool embedding = true> |
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| 117 | struct NodeDataNode { |
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| 118 | int prev, next; |
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| 119 | int visited; |
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| 120 | typename UGraph::Edge first; |
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| 121 | bool inverted; |
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| 122 | }; |
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| 123 | |
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| 124 | template <typename UGraph> |
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| 125 | struct NodeDataNode<UGraph, false> { |
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| 126 | int prev, next; |
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| 127 | int visited; |
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| 128 | }; |
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| 129 | |
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| 130 | template <typename UGraph> |
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| 131 | struct ChildListNode { |
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| 132 | typedef typename UGraph::Node Node; |
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| 133 | Node first; |
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| 134 | Node prev, next; |
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| 135 | }; |
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| 136 | |
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| 137 | template <typename UGraph> |
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| 138 | struct EdgeListNode { |
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| 139 | typename UGraph::Edge prev, next; |
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| 140 | }; |
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| 141 | |
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| 142 | } |
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| 143 | |
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[2499] | 144 | /// \ingroup planar |
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[2480] | 145 | /// |
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| 146 | /// \brief Planarity checking of an undirected simple graph |
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| 147 | /// |
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[2499] | 148 | /// This class implements the Boyer-Myrvold algorithm for planarity |
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[2480] | 149 | /// checking of an undirected graph. This class is a simplified |
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| 150 | /// version of the PlanarEmbedding algorithm class, and it does |
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| 151 | /// provide neither embedding nor kuratowski subdivisons. |
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| 152 | template <typename UGraph> |
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| 153 | class PlanarityChecking { |
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| 154 | private: |
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| 155 | |
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[2499] | 156 | UGRAPH_TYPEDEFS(typename UGraph); |
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[2480] | 157 | |
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| 158 | const UGraph& _ugraph; |
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| 159 | |
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| 160 | private: |
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| 161 | |
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| 162 | typedef typename UGraph::template NodeMap<Edge> PredMap; |
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| 163 | |
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| 164 | typedef typename UGraph::template UEdgeMap<bool> TreeMap; |
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| 165 | |
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| 166 | typedef typename UGraph::template NodeMap<int> OrderMap; |
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| 167 | typedef std::vector<Node> OrderList; |
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| 168 | |
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| 169 | typedef typename UGraph::template NodeMap<int> LowMap; |
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| 170 | typedef typename UGraph::template NodeMap<int> AncestorMap; |
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| 171 | |
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| 172 | typedef _planarity_bits::NodeDataNode<UGraph> NodeDataNode; |
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| 173 | typedef std::vector<NodeDataNode> NodeData; |
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| 174 | |
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| 175 | typedef _planarity_bits::ChildListNode<UGraph> ChildListNode; |
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| 176 | typedef typename UGraph::template NodeMap<ChildListNode> ChildLists; |
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| 177 | |
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| 178 | typedef typename UGraph::template NodeMap<std::list<int> > MergeRoots; |
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| 179 | |
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| 180 | typedef typename UGraph::template NodeMap<bool> EmbedEdge; |
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| 181 | |
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| 182 | public: |
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| 183 | |
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| 184 | /// \brief Constructor |
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| 185 | /// |
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| 186 | /// \warining The graph should be simple, i.e. parallel and loop edge |
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| 187 | /// free. |
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| 188 | PlanarityChecking(const UGraph& ugraph) : _ugraph(ugraph) {} |
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| 189 | |
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| 190 | /// \brief Runs the algorithm. |
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| 191 | /// |
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| 192 | /// Runs the algorithm. |
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| 193 | /// \return %True when the graph is planar. |
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[2481] | 194 | bool run() { |
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[2480] | 195 | typedef _planarity_bits::PlanarityVisitor<UGraph> Visitor; |
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| 196 | |
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| 197 | PredMap pred_map(_ugraph, INVALID); |
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| 198 | TreeMap tree_map(_ugraph, false); |
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| 199 | |
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| 200 | OrderMap order_map(_ugraph, -1); |
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| 201 | OrderList order_list; |
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| 202 | |
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| 203 | AncestorMap ancestor_map(_ugraph, -1); |
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| 204 | LowMap low_map(_ugraph, -1); |
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| 205 | |
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| 206 | Visitor visitor(_ugraph, pred_map, tree_map, |
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| 207 | order_map, order_list, ancestor_map, low_map); |
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| 208 | DfsVisit<UGraph, Visitor> visit(_ugraph, visitor); |
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| 209 | visit.run(); |
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| 210 | |
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| 211 | ChildLists child_lists(_ugraph); |
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| 212 | createChildLists(tree_map, order_map, low_map, child_lists); |
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| 213 | |
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| 214 | NodeData node_data(2 * order_list.size()); |
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| 215 | |
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| 216 | EmbedEdge embed_edge(_ugraph, false); |
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| 217 | |
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| 218 | MergeRoots merge_roots(_ugraph); |
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| 219 | |
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| 220 | for (int i = order_list.size() - 1; i >= 0; --i) { |
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| 221 | |
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| 222 | Node node = order_list[i]; |
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| 223 | |
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| 224 | Node source = node; |
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| 225 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
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| 226 | Node target = _ugraph.target(e); |
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| 227 | |
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| 228 | if (order_map[source] < order_map[target] && tree_map[e]) { |
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[2481] | 229 | initFace(target, node_data, order_map, order_list); |
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[2480] | 230 | } |
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| 231 | } |
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| 232 | |
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| 233 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
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| 234 | Node target = _ugraph.target(e); |
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| 235 | |
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| 236 | if (order_map[source] < order_map[target] && !tree_map[e]) { |
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| 237 | embed_edge[target] = true; |
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| 238 | walkUp(target, source, i, pred_map, low_map, |
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| 239 | order_map, order_list, node_data, merge_roots); |
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| 240 | } |
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| 241 | } |
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| 242 | |
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| 243 | for (typename MergeRoots::Value::iterator it = |
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| 244 | merge_roots[node].begin(); it != merge_roots[node].end(); ++it) { |
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| 245 | int rn = *it; |
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| 246 | walkDown(rn, i, node_data, order_list, child_lists, |
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| 247 | ancestor_map, low_map, embed_edge, merge_roots); |
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| 248 | } |
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| 249 | merge_roots[node].clear(); |
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| 250 | |
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| 251 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
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| 252 | Node target = _ugraph.target(e); |
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| 253 | |
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| 254 | if (order_map[source] < order_map[target] && !tree_map[e]) { |
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| 255 | if (embed_edge[target]) { |
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| 256 | return false; |
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| 257 | } |
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| 258 | } |
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| 259 | } |
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| 260 | } |
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| 261 | |
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| 262 | return true; |
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| 263 | } |
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| 264 | |
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| 265 | private: |
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| 266 | |
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| 267 | void createChildLists(const TreeMap& tree_map, const OrderMap& order_map, |
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| 268 | const LowMap& low_map, ChildLists& child_lists) { |
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| 269 | |
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| 270 | for (NodeIt n(_ugraph); n != INVALID; ++n) { |
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| 271 | Node source = n; |
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| 272 | |
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| 273 | std::vector<Node> targets; |
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| 274 | for (OutEdgeIt e(_ugraph, n); e != INVALID; ++e) { |
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| 275 | Node target = _ugraph.target(e); |
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| 276 | |
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| 277 | if (order_map[source] < order_map[target] && tree_map[e]) { |
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| 278 | targets.push_back(target); |
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| 279 | } |
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| 280 | } |
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| 281 | |
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| 282 | if (targets.size() == 0) { |
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| 283 | child_lists[source].first = INVALID; |
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| 284 | } else if (targets.size() == 1) { |
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| 285 | child_lists[source].first = targets[0]; |
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| 286 | child_lists[targets[0]].prev = INVALID; |
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| 287 | child_lists[targets[0]].next = INVALID; |
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| 288 | } else { |
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| 289 | radixSort(targets.begin(), targets.end(), mapFunctor(low_map)); |
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| 290 | for (int i = 1; i < int(targets.size()); ++i) { |
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| 291 | child_lists[targets[i]].prev = targets[i - 1]; |
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| 292 | child_lists[targets[i - 1]].next = targets[i]; |
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| 293 | } |
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| 294 | child_lists[targets.back()].next = INVALID; |
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| 295 | child_lists[targets.front()].prev = INVALID; |
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| 296 | child_lists[source].first = targets.front(); |
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| 297 | } |
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| 298 | } |
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| 299 | } |
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| 300 | |
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| 301 | void walkUp(const Node& node, Node root, int rorder, |
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| 302 | const PredMap& pred_map, const LowMap& low_map, |
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| 303 | const OrderMap& order_map, const OrderList& order_list, |
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| 304 | NodeData& node_data, MergeRoots& merge_roots) { |
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| 305 | |
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| 306 | int na, nb; |
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| 307 | bool da, db; |
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| 308 | |
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| 309 | na = nb = order_map[node]; |
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| 310 | da = true; db = false; |
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| 311 | |
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| 312 | while (true) { |
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| 313 | |
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| 314 | if (node_data[na].visited == rorder) break; |
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| 315 | if (node_data[nb].visited == rorder) break; |
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| 316 | |
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| 317 | node_data[na].visited = rorder; |
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| 318 | node_data[nb].visited = rorder; |
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| 319 | |
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| 320 | int rn = -1; |
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| 321 | |
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| 322 | if (na >= int(order_list.size())) { |
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| 323 | rn = na; |
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| 324 | } else if (nb >= int(order_list.size())) { |
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| 325 | rn = nb; |
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| 326 | } |
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| 327 | |
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| 328 | if (rn == -1) { |
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| 329 | int nn; |
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| 330 | |
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| 331 | nn = da ? node_data[na].prev : node_data[na].next; |
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| 332 | da = node_data[nn].prev != na; |
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| 333 | na = nn; |
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| 334 | |
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| 335 | nn = db ? node_data[nb].prev : node_data[nb].next; |
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| 336 | db = node_data[nn].prev != nb; |
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| 337 | nb = nn; |
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| 338 | |
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| 339 | } else { |
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| 340 | |
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| 341 | Node rep = order_list[rn - order_list.size()]; |
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| 342 | Node parent = _ugraph.source(pred_map[rep]); |
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| 343 | |
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| 344 | if (low_map[rep] < rorder) { |
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| 345 | merge_roots[parent].push_back(rn); |
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| 346 | } else { |
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| 347 | merge_roots[parent].push_front(rn); |
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| 348 | } |
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| 349 | |
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| 350 | if (parent != root) { |
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| 351 | na = nb = order_map[parent]; |
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| 352 | da = true; db = false; |
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| 353 | } else { |
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| 354 | break; |
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| 355 | } |
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| 356 | } |
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| 357 | } |
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| 358 | } |
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| 359 | |
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| 360 | void walkDown(int rn, int rorder, NodeData& node_data, |
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| 361 | OrderList& order_list, ChildLists& child_lists, |
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| 362 | AncestorMap& ancestor_map, LowMap& low_map, |
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| 363 | EmbedEdge& embed_edge, MergeRoots& merge_roots) { |
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| 364 | |
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| 365 | std::vector<std::pair<int, bool> > merge_stack; |
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| 366 | |
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| 367 | for (int di = 0; di < 2; ++di) { |
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| 368 | bool rd = di == 0; |
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| 369 | int pn = rn; |
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| 370 | int n = rd ? node_data[rn].next : node_data[rn].prev; |
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| 371 | |
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| 372 | while (n != rn) { |
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| 373 | |
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| 374 | Node node = order_list[n]; |
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| 375 | |
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| 376 | if (embed_edge[node]) { |
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| 377 | |
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| 378 | // Merging components on the critical path |
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| 379 | while (!merge_stack.empty()) { |
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| 380 | |
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| 381 | // Component root |
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| 382 | int cn = merge_stack.back().first; |
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| 383 | bool cd = merge_stack.back().second; |
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| 384 | merge_stack.pop_back(); |
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| 385 | |
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| 386 | // Parent of component |
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| 387 | int dn = merge_stack.back().first; |
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| 388 | bool dd = merge_stack.back().second; |
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| 389 | merge_stack.pop_back(); |
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| 390 | |
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| 391 | Node parent = order_list[dn]; |
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| 392 | |
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| 393 | // Erasing from merge_roots |
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| 394 | merge_roots[parent].pop_front(); |
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| 395 | |
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| 396 | Node child = order_list[cn - order_list.size()]; |
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| 397 | |
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| 398 | // Erasing from child_lists |
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| 399 | if (child_lists[child].prev != INVALID) { |
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| 400 | child_lists[child_lists[child].prev].next = |
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| 401 | child_lists[child].next; |
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| 402 | } else { |
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| 403 | child_lists[parent].first = child_lists[child].next; |
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| 404 | } |
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| 405 | |
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| 406 | if (child_lists[child].next != INVALID) { |
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| 407 | child_lists[child_lists[child].next].prev = |
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| 408 | child_lists[child].prev; |
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| 409 | } |
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| 410 | |
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| 411 | // Merging external faces |
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| 412 | { |
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| 413 | int en = cn; |
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| 414 | cn = cd ? node_data[cn].prev : node_data[cn].next; |
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| 415 | cd = node_data[cn].next == en; |
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| 416 | |
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| 417 | } |
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| 418 | |
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| 419 | if (cd) node_data[cn].next = dn; else node_data[cn].prev = dn; |
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| 420 | if (dd) node_data[dn].prev = cn; else node_data[dn].next = cn; |
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| 421 | |
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| 422 | } |
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| 423 | |
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| 424 | bool d = pn == node_data[n].prev; |
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| 425 | |
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| 426 | if (node_data[n].prev == node_data[n].next && |
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| 427 | node_data[n].inverted) { |
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| 428 | d = !d; |
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| 429 | } |
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| 430 | |
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| 431 | // Embedding edge into external face |
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| 432 | if (rd) node_data[rn].next = n; else node_data[rn].prev = n; |
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| 433 | if (d) node_data[n].prev = rn; else node_data[n].next = rn; |
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| 434 | pn = rn; |
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| 435 | |
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| 436 | embed_edge[order_list[n]] = false; |
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| 437 | } |
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| 438 | |
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| 439 | if (!merge_roots[node].empty()) { |
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| 440 | |
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| 441 | bool d = pn == node_data[n].prev; |
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| 442 | |
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| 443 | merge_stack.push_back(std::make_pair(n, d)); |
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| 444 | |
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| 445 | int rn = merge_roots[node].front(); |
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| 446 | |
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| 447 | int xn = node_data[rn].next; |
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| 448 | Node xnode = order_list[xn]; |
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| 449 | |
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| 450 | int yn = node_data[rn].prev; |
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| 451 | Node ynode = order_list[yn]; |
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| 452 | |
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| 453 | bool rd; |
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| 454 | if (!external(xnode, rorder, child_lists, ancestor_map, low_map)) { |
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| 455 | rd = true; |
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| 456 | } else if (!external(ynode, rorder, child_lists, |
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| 457 | ancestor_map, low_map)) { |
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| 458 | rd = false; |
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| 459 | } else if (pertinent(xnode, embed_edge, merge_roots)) { |
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| 460 | rd = true; |
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| 461 | } else { |
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| 462 | rd = false; |
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| 463 | } |
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| 464 | |
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| 465 | merge_stack.push_back(std::make_pair(rn, rd)); |
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| 466 | |
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| 467 | pn = rn; |
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| 468 | n = rd ? xn : yn; |
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| 469 | |
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| 470 | } else if (!external(node, rorder, child_lists, |
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| 471 | ancestor_map, low_map)) { |
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| 472 | int nn = (node_data[n].next != pn ? |
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| 473 | node_data[n].next : node_data[n].prev); |
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| 474 | |
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| 475 | bool nd = n == node_data[nn].prev; |
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| 476 | |
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| 477 | if (nd) node_data[nn].prev = pn; |
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| 478 | else node_data[nn].next = pn; |
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| 479 | |
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| 480 | if (n == node_data[pn].prev) node_data[pn].prev = nn; |
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| 481 | else node_data[pn].next = nn; |
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| 482 | |
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| 483 | node_data[nn].inverted = |
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| 484 | (node_data[nn].prev == node_data[nn].next && nd != rd); |
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| 485 | |
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| 486 | n = nn; |
---|
| 487 | } |
---|
| 488 | else break; |
---|
| 489 | |
---|
| 490 | } |
---|
| 491 | |
---|
| 492 | if (!merge_stack.empty() || n == rn) { |
---|
| 493 | break; |
---|
| 494 | } |
---|
| 495 | } |
---|
| 496 | } |
---|
| 497 | |
---|
| 498 | void initFace(const Node& node, NodeData& node_data, |
---|
[2481] | 499 | const OrderMap& order_map, const OrderList& order_list) { |
---|
[2480] | 500 | int n = order_map[node]; |
---|
| 501 | int rn = n + order_list.size(); |
---|
| 502 | |
---|
| 503 | node_data[n].next = node_data[n].prev = rn; |
---|
| 504 | node_data[rn].next = node_data[rn].prev = n; |
---|
| 505 | |
---|
| 506 | node_data[n].visited = order_list.size(); |
---|
| 507 | node_data[rn].visited = order_list.size(); |
---|
| 508 | |
---|
| 509 | } |
---|
| 510 | |
---|
| 511 | bool external(const Node& node, int rorder, |
---|
| 512 | ChildLists& child_lists, AncestorMap& ancestor_map, |
---|
| 513 | LowMap& low_map) { |
---|
| 514 | Node child = child_lists[node].first; |
---|
| 515 | |
---|
| 516 | if (child != INVALID) { |
---|
| 517 | if (low_map[child] < rorder) return true; |
---|
| 518 | } |
---|
| 519 | |
---|
| 520 | if (ancestor_map[node] < rorder) return true; |
---|
| 521 | |
---|
| 522 | return false; |
---|
| 523 | } |
---|
| 524 | |
---|
| 525 | bool pertinent(const Node& node, const EmbedEdge& embed_edge, |
---|
| 526 | const MergeRoots& merge_roots) { |
---|
| 527 | return !merge_roots[node].empty() || embed_edge[node]; |
---|
| 528 | } |
---|
| 529 | |
---|
| 530 | }; |
---|
| 531 | |
---|
[2499] | 532 | /// \ingroup planar |
---|
[2480] | 533 | /// |
---|
| 534 | /// \brief Planar embedding of an undirected simple graph |
---|
| 535 | /// |
---|
| 536 | /// This class implements the Boyer-Myrvold algorithm for planar |
---|
| 537 | /// embedding of an undirected graph. The planar embeding is an |
---|
| 538 | /// ordering of the outgoing edges in each node, which is a possible |
---|
| 539 | /// configuration to draw the graph in the plane. If there is not |
---|
| 540 | /// such ordering then the graph contains a \f$ K_5 \f$ (full graph |
---|
| 541 | /// with 5 nodes) or an \f$ K_{3,3} \f$ (complete bipartite graph on |
---|
| 542 | /// 3 ANode and 3 BNode) subdivision. |
---|
| 543 | /// |
---|
| 544 | /// The current implementation calculates an embedding or an |
---|
| 545 | /// Kuratowski subdivision if the graph is not planar. The running |
---|
| 546 | /// time of the algorithm is \f$ O(n) \f$. |
---|
| 547 | template <typename UGraph> |
---|
| 548 | class PlanarEmbedding { |
---|
| 549 | private: |
---|
| 550 | |
---|
[2499] | 551 | UGRAPH_TYPEDEFS(typename UGraph); |
---|
[2480] | 552 | |
---|
| 553 | const UGraph& _ugraph; |
---|
| 554 | typename UGraph::template EdgeMap<Edge> _embedding; |
---|
| 555 | |
---|
| 556 | typename UGraph::template UEdgeMap<bool> _kuratowski; |
---|
| 557 | |
---|
| 558 | private: |
---|
| 559 | |
---|
| 560 | typedef typename UGraph::template NodeMap<Edge> PredMap; |
---|
| 561 | |
---|
| 562 | typedef typename UGraph::template UEdgeMap<bool> TreeMap; |
---|
| 563 | |
---|
| 564 | typedef typename UGraph::template NodeMap<int> OrderMap; |
---|
| 565 | typedef std::vector<Node> OrderList; |
---|
| 566 | |
---|
| 567 | typedef typename UGraph::template NodeMap<int> LowMap; |
---|
| 568 | typedef typename UGraph::template NodeMap<int> AncestorMap; |
---|
| 569 | |
---|
| 570 | typedef _planarity_bits::NodeDataNode<UGraph> NodeDataNode; |
---|
| 571 | typedef std::vector<NodeDataNode> NodeData; |
---|
| 572 | |
---|
| 573 | typedef _planarity_bits::ChildListNode<UGraph> ChildListNode; |
---|
| 574 | typedef typename UGraph::template NodeMap<ChildListNode> ChildLists; |
---|
| 575 | |
---|
| 576 | typedef typename UGraph::template NodeMap<std::list<int> > MergeRoots; |
---|
| 577 | |
---|
| 578 | typedef typename UGraph::template NodeMap<Edge> EmbedEdge; |
---|
| 579 | |
---|
| 580 | typedef _planarity_bits::EdgeListNode<UGraph> EdgeListNode; |
---|
| 581 | typedef typename UGraph::template EdgeMap<EdgeListNode> EdgeLists; |
---|
| 582 | |
---|
| 583 | typedef typename UGraph::template NodeMap<bool> FlipMap; |
---|
| 584 | |
---|
| 585 | typedef typename UGraph::template NodeMap<int> TypeMap; |
---|
| 586 | |
---|
| 587 | enum IsolatorNodeType { |
---|
| 588 | HIGHX = 6, LOWX = 7, |
---|
| 589 | HIGHY = 8, LOWY = 9, |
---|
| 590 | ROOT = 10, PERTINENT = 11, |
---|
| 591 | INTERNAL = 12 |
---|
| 592 | }; |
---|
| 593 | |
---|
| 594 | public: |
---|
| 595 | |
---|
[2499] | 596 | /// \brief The map for store of embedding |
---|
| 597 | typedef typename UGraph::template EdgeMap<Edge> EmbeddingMap; |
---|
| 598 | |
---|
[2480] | 599 | /// \brief Constructor |
---|
| 600 | /// |
---|
| 601 | /// \warining The graph should be simple, i.e. parallel and loop edge |
---|
| 602 | /// free. |
---|
| 603 | PlanarEmbedding(const UGraph& ugraph) |
---|
| 604 | : _ugraph(ugraph), _embedding(_ugraph), _kuratowski(ugraph, false) {} |
---|
| 605 | |
---|
| 606 | /// \brief Runs the algorithm. |
---|
| 607 | /// |
---|
| 608 | /// Runs the algorithm. |
---|
| 609 | /// \param kuratowski If the parameter is false, then the |
---|
| 610 | /// algorithm does not calculate the isolate Kuratowski |
---|
| 611 | /// subdivisions. |
---|
| 612 | ///\return %True when the graph is planar. |
---|
| 613 | bool run(bool kuratowski = true) { |
---|
| 614 | typedef _planarity_bits::PlanarityVisitor<UGraph> Visitor; |
---|
| 615 | |
---|
| 616 | PredMap pred_map(_ugraph, INVALID); |
---|
| 617 | TreeMap tree_map(_ugraph, false); |
---|
| 618 | |
---|
| 619 | OrderMap order_map(_ugraph, -1); |
---|
| 620 | OrderList order_list; |
---|
| 621 | |
---|
| 622 | AncestorMap ancestor_map(_ugraph, -1); |
---|
| 623 | LowMap low_map(_ugraph, -1); |
---|
| 624 | |
---|
| 625 | Visitor visitor(_ugraph, pred_map, tree_map, |
---|
| 626 | order_map, order_list, ancestor_map, low_map); |
---|
| 627 | DfsVisit<UGraph, Visitor> visit(_ugraph, visitor); |
---|
| 628 | visit.run(); |
---|
| 629 | |
---|
| 630 | ChildLists child_lists(_ugraph); |
---|
| 631 | createChildLists(tree_map, order_map, low_map, child_lists); |
---|
| 632 | |
---|
| 633 | NodeData node_data(2 * order_list.size()); |
---|
| 634 | |
---|
| 635 | EmbedEdge embed_edge(_ugraph, INVALID); |
---|
| 636 | |
---|
| 637 | MergeRoots merge_roots(_ugraph); |
---|
| 638 | |
---|
| 639 | EdgeLists edge_lists(_ugraph); |
---|
| 640 | |
---|
| 641 | FlipMap flip_map(_ugraph, false); |
---|
| 642 | |
---|
| 643 | for (int i = order_list.size() - 1; i >= 0; --i) { |
---|
| 644 | |
---|
| 645 | Node node = order_list[i]; |
---|
| 646 | |
---|
| 647 | node_data[i].first = INVALID; |
---|
| 648 | |
---|
| 649 | Node source = node; |
---|
| 650 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
---|
| 651 | Node target = _ugraph.target(e); |
---|
| 652 | |
---|
| 653 | if (order_map[source] < order_map[target] && tree_map[e]) { |
---|
| 654 | initFace(target, edge_lists, node_data, |
---|
| 655 | pred_map, order_map, order_list); |
---|
| 656 | } |
---|
| 657 | } |
---|
| 658 | |
---|
| 659 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
---|
| 660 | Node target = _ugraph.target(e); |
---|
| 661 | |
---|
| 662 | if (order_map[source] < order_map[target] && !tree_map[e]) { |
---|
| 663 | embed_edge[target] = e; |
---|
| 664 | walkUp(target, source, i, pred_map, low_map, |
---|
| 665 | order_map, order_list, node_data, merge_roots); |
---|
| 666 | } |
---|
| 667 | } |
---|
| 668 | |
---|
| 669 | for (typename MergeRoots::Value::iterator it = |
---|
| 670 | merge_roots[node].begin(); it != merge_roots[node].end(); ++it) { |
---|
| 671 | int rn = *it; |
---|
| 672 | walkDown(rn, i, node_data, edge_lists, flip_map, order_list, |
---|
| 673 | child_lists, ancestor_map, low_map, embed_edge, merge_roots); |
---|
| 674 | } |
---|
| 675 | merge_roots[node].clear(); |
---|
| 676 | |
---|
| 677 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
---|
| 678 | Node target = _ugraph.target(e); |
---|
| 679 | |
---|
| 680 | if (order_map[source] < order_map[target] && !tree_map[e]) { |
---|
| 681 | if (embed_edge[target] != INVALID) { |
---|
| 682 | if (kuratowski) { |
---|
| 683 | isolateKuratowski(e, node_data, edge_lists, flip_map, |
---|
| 684 | order_map, order_list, pred_map, child_lists, |
---|
| 685 | ancestor_map, low_map, |
---|
| 686 | embed_edge, merge_roots); |
---|
| 687 | } |
---|
| 688 | return false; |
---|
| 689 | } |
---|
| 690 | } |
---|
| 691 | } |
---|
| 692 | } |
---|
| 693 | |
---|
| 694 | for (int i = 0; i < int(order_list.size()); ++i) { |
---|
| 695 | |
---|
| 696 | mergeRemainingFaces(order_list[i], node_data, order_list, order_map, |
---|
| 697 | child_lists, edge_lists); |
---|
| 698 | storeEmbedding(order_list[i], node_data, order_map, pred_map, |
---|
| 699 | edge_lists, flip_map); |
---|
| 700 | } |
---|
| 701 | |
---|
| 702 | return true; |
---|
| 703 | } |
---|
| 704 | |
---|
| 705 | /// \brief Gives back the successor of an edge |
---|
| 706 | /// |
---|
| 707 | /// Gives back the successor of an edge. This function makes |
---|
| 708 | /// possible to query the cyclic order of the outgoing edges from |
---|
| 709 | /// a node. |
---|
| 710 | Edge next(const Edge& edge) const { |
---|
| 711 | return _embedding[edge]; |
---|
| 712 | } |
---|
| 713 | |
---|
[2499] | 714 | /// \brief Gives back the calculated embedding map |
---|
| 715 | /// |
---|
| 716 | /// The returned map contains the successor of each edge in the |
---|
| 717 | /// graph. |
---|
| 718 | const EmbeddingMap& embedding() const { |
---|
| 719 | return _embedding; |
---|
| 720 | } |
---|
| 721 | |
---|
[2480] | 722 | /// \brief Gives back true when the undirected edge is in the |
---|
| 723 | /// kuratowski subdivision |
---|
| 724 | /// |
---|
| 725 | /// Gives back true when the undirected edge is in the kuratowski |
---|
| 726 | /// subdivision |
---|
| 727 | bool kuratowski(const UEdge& uedge) { |
---|
| 728 | return _kuratowski[uedge]; |
---|
| 729 | } |
---|
| 730 | |
---|
| 731 | private: |
---|
| 732 | |
---|
| 733 | void createChildLists(const TreeMap& tree_map, const OrderMap& order_map, |
---|
| 734 | const LowMap& low_map, ChildLists& child_lists) { |
---|
| 735 | |
---|
| 736 | for (NodeIt n(_ugraph); n != INVALID; ++n) { |
---|
| 737 | Node source = n; |
---|
| 738 | |
---|
| 739 | std::vector<Node> targets; |
---|
| 740 | for (OutEdgeIt e(_ugraph, n); e != INVALID; ++e) { |
---|
| 741 | Node target = _ugraph.target(e); |
---|
| 742 | |
---|
| 743 | if (order_map[source] < order_map[target] && tree_map[e]) { |
---|
| 744 | targets.push_back(target); |
---|
| 745 | } |
---|
| 746 | } |
---|
| 747 | |
---|
| 748 | if (targets.size() == 0) { |
---|
| 749 | child_lists[source].first = INVALID; |
---|
| 750 | } else if (targets.size() == 1) { |
---|
| 751 | child_lists[source].first = targets[0]; |
---|
| 752 | child_lists[targets[0]].prev = INVALID; |
---|
| 753 | child_lists[targets[0]].next = INVALID; |
---|
| 754 | } else { |
---|
| 755 | radixSort(targets.begin(), targets.end(), mapFunctor(low_map)); |
---|
| 756 | for (int i = 1; i < int(targets.size()); ++i) { |
---|
| 757 | child_lists[targets[i]].prev = targets[i - 1]; |
---|
| 758 | child_lists[targets[i - 1]].next = targets[i]; |
---|
| 759 | } |
---|
| 760 | child_lists[targets.back()].next = INVALID; |
---|
| 761 | child_lists[targets.front()].prev = INVALID; |
---|
| 762 | child_lists[source].first = targets.front(); |
---|
| 763 | } |
---|
| 764 | } |
---|
| 765 | } |
---|
| 766 | |
---|
| 767 | void walkUp(const Node& node, Node root, int rorder, |
---|
| 768 | const PredMap& pred_map, const LowMap& low_map, |
---|
| 769 | const OrderMap& order_map, const OrderList& order_list, |
---|
| 770 | NodeData& node_data, MergeRoots& merge_roots) { |
---|
| 771 | |
---|
| 772 | int na, nb; |
---|
| 773 | bool da, db; |
---|
| 774 | |
---|
| 775 | na = nb = order_map[node]; |
---|
| 776 | da = true; db = false; |
---|
| 777 | |
---|
| 778 | while (true) { |
---|
| 779 | |
---|
| 780 | if (node_data[na].visited == rorder) break; |
---|
| 781 | if (node_data[nb].visited == rorder) break; |
---|
| 782 | |
---|
| 783 | node_data[na].visited = rorder; |
---|
| 784 | node_data[nb].visited = rorder; |
---|
| 785 | |
---|
| 786 | int rn = -1; |
---|
| 787 | |
---|
| 788 | if (na >= int(order_list.size())) { |
---|
| 789 | rn = na; |
---|
| 790 | } else if (nb >= int(order_list.size())) { |
---|
| 791 | rn = nb; |
---|
| 792 | } |
---|
| 793 | |
---|
| 794 | if (rn == -1) { |
---|
| 795 | int nn; |
---|
| 796 | |
---|
| 797 | nn = da ? node_data[na].prev : node_data[na].next; |
---|
| 798 | da = node_data[nn].prev != na; |
---|
| 799 | na = nn; |
---|
| 800 | |
---|
| 801 | nn = db ? node_data[nb].prev : node_data[nb].next; |
---|
| 802 | db = node_data[nn].prev != nb; |
---|
| 803 | nb = nn; |
---|
| 804 | |
---|
| 805 | } else { |
---|
| 806 | |
---|
| 807 | Node rep = order_list[rn - order_list.size()]; |
---|
| 808 | Node parent = _ugraph.source(pred_map[rep]); |
---|
| 809 | |
---|
| 810 | if (low_map[rep] < rorder) { |
---|
| 811 | merge_roots[parent].push_back(rn); |
---|
| 812 | } else { |
---|
| 813 | merge_roots[parent].push_front(rn); |
---|
| 814 | } |
---|
| 815 | |
---|
| 816 | if (parent != root) { |
---|
| 817 | na = nb = order_map[parent]; |
---|
| 818 | da = true; db = false; |
---|
| 819 | } else { |
---|
| 820 | break; |
---|
| 821 | } |
---|
| 822 | } |
---|
| 823 | } |
---|
| 824 | } |
---|
| 825 | |
---|
| 826 | void walkDown(int rn, int rorder, NodeData& node_data, |
---|
| 827 | EdgeLists& edge_lists, FlipMap& flip_map, |
---|
| 828 | OrderList& order_list, ChildLists& child_lists, |
---|
| 829 | AncestorMap& ancestor_map, LowMap& low_map, |
---|
| 830 | EmbedEdge& embed_edge, MergeRoots& merge_roots) { |
---|
| 831 | |
---|
| 832 | std::vector<std::pair<int, bool> > merge_stack; |
---|
| 833 | |
---|
| 834 | for (int di = 0; di < 2; ++di) { |
---|
| 835 | bool rd = di == 0; |
---|
| 836 | int pn = rn; |
---|
| 837 | int n = rd ? node_data[rn].next : node_data[rn].prev; |
---|
| 838 | |
---|
| 839 | while (n != rn) { |
---|
| 840 | |
---|
| 841 | Node node = order_list[n]; |
---|
| 842 | |
---|
| 843 | if (embed_edge[node] != INVALID) { |
---|
| 844 | |
---|
| 845 | // Merging components on the critical path |
---|
| 846 | while (!merge_stack.empty()) { |
---|
| 847 | |
---|
| 848 | // Component root |
---|
| 849 | int cn = merge_stack.back().first; |
---|
| 850 | bool cd = merge_stack.back().second; |
---|
| 851 | merge_stack.pop_back(); |
---|
| 852 | |
---|
| 853 | // Parent of component |
---|
| 854 | int dn = merge_stack.back().first; |
---|
| 855 | bool dd = merge_stack.back().second; |
---|
| 856 | merge_stack.pop_back(); |
---|
| 857 | |
---|
| 858 | Node parent = order_list[dn]; |
---|
| 859 | |
---|
| 860 | // Erasing from merge_roots |
---|
| 861 | merge_roots[parent].pop_front(); |
---|
| 862 | |
---|
| 863 | Node child = order_list[cn - order_list.size()]; |
---|
| 864 | |
---|
| 865 | // Erasing from child_lists |
---|
| 866 | if (child_lists[child].prev != INVALID) { |
---|
| 867 | child_lists[child_lists[child].prev].next = |
---|
| 868 | child_lists[child].next; |
---|
| 869 | } else { |
---|
| 870 | child_lists[parent].first = child_lists[child].next; |
---|
| 871 | } |
---|
| 872 | |
---|
| 873 | if (child_lists[child].next != INVALID) { |
---|
| 874 | child_lists[child_lists[child].next].prev = |
---|
| 875 | child_lists[child].prev; |
---|
| 876 | } |
---|
| 877 | |
---|
| 878 | // Merging edges + flipping |
---|
| 879 | Edge de = node_data[dn].first; |
---|
| 880 | Edge ce = node_data[cn].first; |
---|
| 881 | |
---|
| 882 | flip_map[order_list[cn - order_list.size()]] = cd != dd; |
---|
| 883 | if (cd != dd) { |
---|
| 884 | std::swap(edge_lists[ce].prev, edge_lists[ce].next); |
---|
| 885 | ce = edge_lists[ce].prev; |
---|
| 886 | std::swap(edge_lists[ce].prev, edge_lists[ce].next); |
---|
| 887 | } |
---|
| 888 | |
---|
| 889 | { |
---|
| 890 | Edge dne = edge_lists[de].next; |
---|
| 891 | Edge cne = edge_lists[ce].next; |
---|
| 892 | |
---|
| 893 | edge_lists[de].next = cne; |
---|
| 894 | edge_lists[ce].next = dne; |
---|
| 895 | |
---|
| 896 | edge_lists[dne].prev = ce; |
---|
| 897 | edge_lists[cne].prev = de; |
---|
| 898 | } |
---|
| 899 | |
---|
| 900 | if (dd) { |
---|
| 901 | node_data[dn].first = ce; |
---|
| 902 | } |
---|
| 903 | |
---|
| 904 | // Merging external faces |
---|
| 905 | { |
---|
| 906 | int en = cn; |
---|
| 907 | cn = cd ? node_data[cn].prev : node_data[cn].next; |
---|
| 908 | cd = node_data[cn].next == en; |
---|
| 909 | |
---|
| 910 | if (node_data[cn].prev == node_data[cn].next && |
---|
| 911 | node_data[cn].inverted) { |
---|
| 912 | cd = !cd; |
---|
| 913 | } |
---|
| 914 | } |
---|
| 915 | |
---|
| 916 | if (cd) node_data[cn].next = dn; else node_data[cn].prev = dn; |
---|
| 917 | if (dd) node_data[dn].prev = cn; else node_data[dn].next = cn; |
---|
| 918 | |
---|
| 919 | } |
---|
| 920 | |
---|
| 921 | bool d = pn == node_data[n].prev; |
---|
| 922 | |
---|
| 923 | if (node_data[n].prev == node_data[n].next && |
---|
| 924 | node_data[n].inverted) { |
---|
| 925 | d = !d; |
---|
| 926 | } |
---|
| 927 | |
---|
| 928 | // Add new edge |
---|
| 929 | { |
---|
| 930 | Edge edge = embed_edge[node]; |
---|
| 931 | Edge re = node_data[rn].first; |
---|
| 932 | |
---|
| 933 | edge_lists[edge_lists[re].next].prev = edge; |
---|
| 934 | edge_lists[edge].next = edge_lists[re].next; |
---|
| 935 | edge_lists[edge].prev = re; |
---|
| 936 | edge_lists[re].next = edge; |
---|
| 937 | |
---|
| 938 | if (!rd) { |
---|
| 939 | node_data[rn].first = edge; |
---|
| 940 | } |
---|
| 941 | |
---|
| 942 | Edge rev = _ugraph.oppositeEdge(edge); |
---|
| 943 | Edge e = node_data[n].first; |
---|
| 944 | |
---|
| 945 | edge_lists[edge_lists[e].next].prev = rev; |
---|
| 946 | edge_lists[rev].next = edge_lists[e].next; |
---|
| 947 | edge_lists[rev].prev = e; |
---|
| 948 | edge_lists[e].next = rev; |
---|
| 949 | |
---|
| 950 | if (d) { |
---|
| 951 | node_data[n].first = rev; |
---|
| 952 | } |
---|
| 953 | |
---|
| 954 | } |
---|
| 955 | |
---|
| 956 | // Embedding edge into external face |
---|
| 957 | if (rd) node_data[rn].next = n; else node_data[rn].prev = n; |
---|
| 958 | if (d) node_data[n].prev = rn; else node_data[n].next = rn; |
---|
| 959 | pn = rn; |
---|
| 960 | |
---|
| 961 | embed_edge[order_list[n]] = INVALID; |
---|
| 962 | } |
---|
| 963 | |
---|
| 964 | if (!merge_roots[node].empty()) { |
---|
| 965 | |
---|
| 966 | bool d = pn == node_data[n].prev; |
---|
| 967 | if (node_data[n].prev == node_data[n].next && |
---|
| 968 | node_data[n].inverted) { |
---|
| 969 | d = !d; |
---|
| 970 | } |
---|
| 971 | |
---|
| 972 | merge_stack.push_back(std::make_pair(n, d)); |
---|
| 973 | |
---|
| 974 | int rn = merge_roots[node].front(); |
---|
| 975 | |
---|
| 976 | int xn = node_data[rn].next; |
---|
| 977 | Node xnode = order_list[xn]; |
---|
| 978 | |
---|
| 979 | int yn = node_data[rn].prev; |
---|
| 980 | Node ynode = order_list[yn]; |
---|
| 981 | |
---|
| 982 | bool rd; |
---|
| 983 | if (!external(xnode, rorder, child_lists, ancestor_map, low_map)) { |
---|
| 984 | rd = true; |
---|
| 985 | } else if (!external(ynode, rorder, child_lists, |
---|
| 986 | ancestor_map, low_map)) { |
---|
| 987 | rd = false; |
---|
| 988 | } else if (pertinent(xnode, embed_edge, merge_roots)) { |
---|
| 989 | rd = true; |
---|
| 990 | } else { |
---|
| 991 | rd = false; |
---|
| 992 | } |
---|
| 993 | |
---|
| 994 | merge_stack.push_back(std::make_pair(rn, rd)); |
---|
| 995 | |
---|
| 996 | pn = rn; |
---|
| 997 | n = rd ? xn : yn; |
---|
| 998 | |
---|
| 999 | } else if (!external(node, rorder, child_lists, |
---|
| 1000 | ancestor_map, low_map)) { |
---|
| 1001 | int nn = (node_data[n].next != pn ? |
---|
| 1002 | node_data[n].next : node_data[n].prev); |
---|
| 1003 | |
---|
| 1004 | bool nd = n == node_data[nn].prev; |
---|
| 1005 | |
---|
| 1006 | if (nd) node_data[nn].prev = pn; |
---|
| 1007 | else node_data[nn].next = pn; |
---|
| 1008 | |
---|
| 1009 | if (n == node_data[pn].prev) node_data[pn].prev = nn; |
---|
| 1010 | else node_data[pn].next = nn; |
---|
| 1011 | |
---|
| 1012 | node_data[nn].inverted = |
---|
| 1013 | (node_data[nn].prev == node_data[nn].next && nd != rd); |
---|
| 1014 | |
---|
| 1015 | n = nn; |
---|
| 1016 | } |
---|
| 1017 | else break; |
---|
| 1018 | |
---|
| 1019 | } |
---|
| 1020 | |
---|
| 1021 | if (!merge_stack.empty() || n == rn) { |
---|
| 1022 | break; |
---|
| 1023 | } |
---|
| 1024 | } |
---|
| 1025 | } |
---|
| 1026 | |
---|
| 1027 | void initFace(const Node& node, EdgeLists& edge_lists, |
---|
| 1028 | NodeData& node_data, const PredMap& pred_map, |
---|
| 1029 | const OrderMap& order_map, const OrderList& order_list) { |
---|
| 1030 | int n = order_map[node]; |
---|
| 1031 | int rn = n + order_list.size(); |
---|
| 1032 | |
---|
| 1033 | node_data[n].next = node_data[n].prev = rn; |
---|
| 1034 | node_data[rn].next = node_data[rn].prev = n; |
---|
| 1035 | |
---|
| 1036 | node_data[n].visited = order_list.size(); |
---|
| 1037 | node_data[rn].visited = order_list.size(); |
---|
| 1038 | |
---|
| 1039 | node_data[n].inverted = false; |
---|
| 1040 | node_data[rn].inverted = false; |
---|
| 1041 | |
---|
| 1042 | Edge edge = pred_map[node]; |
---|
| 1043 | Edge rev = _ugraph.oppositeEdge(edge); |
---|
| 1044 | |
---|
| 1045 | node_data[rn].first = edge; |
---|
| 1046 | node_data[n].first = rev; |
---|
| 1047 | |
---|
| 1048 | edge_lists[edge].prev = edge; |
---|
| 1049 | edge_lists[edge].next = edge; |
---|
| 1050 | |
---|
| 1051 | edge_lists[rev].prev = rev; |
---|
| 1052 | edge_lists[rev].next = rev; |
---|
| 1053 | |
---|
| 1054 | } |
---|
| 1055 | |
---|
| 1056 | void mergeRemainingFaces(const Node& node, NodeData& node_data, |
---|
| 1057 | OrderList& order_list, OrderMap& order_map, |
---|
| 1058 | ChildLists& child_lists, EdgeLists& edge_lists) { |
---|
| 1059 | while (child_lists[node].first != INVALID) { |
---|
| 1060 | int dd = order_map[node]; |
---|
| 1061 | Node child = child_lists[node].first; |
---|
| 1062 | int cd = order_map[child] + order_list.size(); |
---|
| 1063 | child_lists[node].first = child_lists[child].next; |
---|
| 1064 | |
---|
| 1065 | Edge de = node_data[dd].first; |
---|
| 1066 | Edge ce = node_data[cd].first; |
---|
| 1067 | |
---|
| 1068 | if (de != INVALID) { |
---|
| 1069 | Edge dne = edge_lists[de].next; |
---|
| 1070 | Edge cne = edge_lists[ce].next; |
---|
| 1071 | |
---|
| 1072 | edge_lists[de].next = cne; |
---|
| 1073 | edge_lists[ce].next = dne; |
---|
| 1074 | |
---|
| 1075 | edge_lists[dne].prev = ce; |
---|
| 1076 | edge_lists[cne].prev = de; |
---|
| 1077 | } |
---|
| 1078 | |
---|
| 1079 | node_data[dd].first = ce; |
---|
| 1080 | |
---|
| 1081 | } |
---|
| 1082 | } |
---|
| 1083 | |
---|
| 1084 | void storeEmbedding(const Node& node, NodeData& node_data, |
---|
| 1085 | OrderMap& order_map, PredMap& pred_map, |
---|
| 1086 | EdgeLists& edge_lists, FlipMap& flip_map) { |
---|
| 1087 | |
---|
| 1088 | if (node_data[order_map[node]].first == INVALID) return; |
---|
| 1089 | |
---|
| 1090 | if (pred_map[node] != INVALID) { |
---|
| 1091 | Node source = _ugraph.source(pred_map[node]); |
---|
| 1092 | flip_map[node] = flip_map[node] != flip_map[source]; |
---|
| 1093 | } |
---|
| 1094 | |
---|
| 1095 | Edge first = node_data[order_map[node]].first; |
---|
| 1096 | Edge prev = first; |
---|
| 1097 | |
---|
| 1098 | Edge edge = flip_map[node] ? |
---|
| 1099 | edge_lists[prev].prev : edge_lists[prev].next; |
---|
| 1100 | |
---|
| 1101 | _embedding[prev] = edge; |
---|
| 1102 | |
---|
| 1103 | while (edge != first) { |
---|
| 1104 | Edge next = edge_lists[edge].prev == prev ? |
---|
| 1105 | edge_lists[edge].next : edge_lists[edge].prev; |
---|
| 1106 | prev = edge; edge = next; |
---|
| 1107 | _embedding[prev] = edge; |
---|
| 1108 | } |
---|
| 1109 | } |
---|
| 1110 | |
---|
| 1111 | |
---|
| 1112 | bool external(const Node& node, int rorder, |
---|
| 1113 | ChildLists& child_lists, AncestorMap& ancestor_map, |
---|
| 1114 | LowMap& low_map) { |
---|
| 1115 | Node child = child_lists[node].first; |
---|
| 1116 | |
---|
| 1117 | if (child != INVALID) { |
---|
| 1118 | if (low_map[child] < rorder) return true; |
---|
| 1119 | } |
---|
| 1120 | |
---|
| 1121 | if (ancestor_map[node] < rorder) return true; |
---|
| 1122 | |
---|
| 1123 | return false; |
---|
| 1124 | } |
---|
| 1125 | |
---|
| 1126 | bool pertinent(const Node& node, const EmbedEdge& embed_edge, |
---|
| 1127 | const MergeRoots& merge_roots) { |
---|
| 1128 | return !merge_roots[node].empty() || embed_edge[node] != INVALID; |
---|
| 1129 | } |
---|
| 1130 | |
---|
| 1131 | int lowPoint(const Node& node, OrderMap& order_map, ChildLists& child_lists, |
---|
| 1132 | AncestorMap& ancestor_map, LowMap& low_map) { |
---|
| 1133 | int low_point; |
---|
| 1134 | |
---|
| 1135 | Node child = child_lists[node].first; |
---|
| 1136 | |
---|
| 1137 | if (child != INVALID) { |
---|
| 1138 | low_point = low_map[child]; |
---|
| 1139 | } else { |
---|
| 1140 | low_point = order_map[node]; |
---|
| 1141 | } |
---|
| 1142 | |
---|
| 1143 | if (low_point > ancestor_map[node]) { |
---|
| 1144 | low_point = ancestor_map[node]; |
---|
| 1145 | } |
---|
| 1146 | |
---|
| 1147 | return low_point; |
---|
| 1148 | } |
---|
| 1149 | |
---|
| 1150 | int findComponentRoot(Node root, Node node, ChildLists& child_lists, |
---|
| 1151 | OrderMap& order_map, OrderList& order_list) { |
---|
| 1152 | |
---|
| 1153 | int order = order_map[root]; |
---|
| 1154 | int norder = order_map[node]; |
---|
| 1155 | |
---|
| 1156 | Node child = child_lists[root].first; |
---|
| 1157 | while (child != INVALID) { |
---|
| 1158 | int corder = order_map[child]; |
---|
| 1159 | if (corder > order && corder < norder) { |
---|
| 1160 | order = corder; |
---|
| 1161 | } |
---|
| 1162 | child = child_lists[child].next; |
---|
| 1163 | } |
---|
| 1164 | return order + order_list.size(); |
---|
| 1165 | } |
---|
| 1166 | |
---|
| 1167 | Node findPertinent(Node node, OrderMap& order_map, NodeData& node_data, |
---|
| 1168 | EmbedEdge& embed_edge, MergeRoots& merge_roots) { |
---|
| 1169 | Node wnode =_ugraph.target(node_data[order_map[node]].first); |
---|
| 1170 | while (!pertinent(wnode, embed_edge, merge_roots)) { |
---|
| 1171 | wnode = _ugraph.target(node_data[order_map[wnode]].first); |
---|
| 1172 | } |
---|
| 1173 | return wnode; |
---|
| 1174 | } |
---|
| 1175 | |
---|
| 1176 | |
---|
| 1177 | Node findExternal(Node node, int rorder, OrderMap& order_map, |
---|
| 1178 | ChildLists& child_lists, AncestorMap& ancestor_map, |
---|
| 1179 | LowMap& low_map, NodeData& node_data) { |
---|
| 1180 | Node wnode =_ugraph.target(node_data[order_map[node]].first); |
---|
| 1181 | while (!external(wnode, rorder, child_lists, ancestor_map, low_map)) { |
---|
| 1182 | wnode = _ugraph.target(node_data[order_map[wnode]].first); |
---|
| 1183 | } |
---|
| 1184 | return wnode; |
---|
| 1185 | } |
---|
| 1186 | |
---|
| 1187 | void markCommonPath(Node node, int rorder, Node& wnode, Node& znode, |
---|
| 1188 | OrderList& order_list, OrderMap& order_map, |
---|
| 1189 | NodeData& node_data, EdgeLists& edge_lists, |
---|
| 1190 | EmbedEdge& embed_edge, MergeRoots& merge_roots, |
---|
| 1191 | ChildLists& child_lists, AncestorMap& ancestor_map, |
---|
| 1192 | LowMap& low_map) { |
---|
| 1193 | |
---|
| 1194 | Node cnode = node; |
---|
| 1195 | Node pred = INVALID; |
---|
| 1196 | |
---|
| 1197 | while (true) { |
---|
| 1198 | |
---|
| 1199 | bool pert = pertinent(cnode, embed_edge, merge_roots); |
---|
| 1200 | bool ext = external(cnode, rorder, child_lists, ancestor_map, low_map); |
---|
| 1201 | |
---|
| 1202 | if (pert && ext) { |
---|
| 1203 | if (!merge_roots[cnode].empty()) { |
---|
| 1204 | int cn = merge_roots[cnode].back(); |
---|
| 1205 | |
---|
| 1206 | if (low_map[order_list[cn - order_list.size()]] < rorder) { |
---|
| 1207 | Edge edge = node_data[cn].first; |
---|
| 1208 | _kuratowski.set(edge, true); |
---|
| 1209 | |
---|
| 1210 | pred = cnode; |
---|
| 1211 | cnode = _ugraph.target(edge); |
---|
| 1212 | |
---|
| 1213 | continue; |
---|
| 1214 | } |
---|
| 1215 | } |
---|
| 1216 | wnode = znode = cnode; |
---|
| 1217 | return; |
---|
| 1218 | |
---|
| 1219 | } else if (pert) { |
---|
| 1220 | wnode = cnode; |
---|
| 1221 | |
---|
| 1222 | while (!external(cnode, rorder, child_lists, ancestor_map, low_map)) { |
---|
| 1223 | Edge edge = node_data[order_map[cnode]].first; |
---|
| 1224 | |
---|
| 1225 | if (_ugraph.target(edge) == pred) { |
---|
| 1226 | edge = edge_lists[edge].next; |
---|
| 1227 | } |
---|
| 1228 | _kuratowski.set(edge, true); |
---|
| 1229 | |
---|
| 1230 | Node next = _ugraph.target(edge); |
---|
| 1231 | pred = cnode; cnode = next; |
---|
| 1232 | } |
---|
| 1233 | |
---|
| 1234 | znode = cnode; |
---|
| 1235 | return; |
---|
| 1236 | |
---|
| 1237 | } else if (ext) { |
---|
| 1238 | znode = cnode; |
---|
| 1239 | |
---|
| 1240 | while (!pertinent(cnode, embed_edge, merge_roots)) { |
---|
| 1241 | Edge edge = node_data[order_map[cnode]].first; |
---|
| 1242 | |
---|
| 1243 | if (_ugraph.target(edge) == pred) { |
---|
| 1244 | edge = edge_lists[edge].next; |
---|
| 1245 | } |
---|
| 1246 | _kuratowski.set(edge, true); |
---|
| 1247 | |
---|
| 1248 | Node next = _ugraph.target(edge); |
---|
| 1249 | pred = cnode; cnode = next; |
---|
| 1250 | } |
---|
| 1251 | |
---|
| 1252 | wnode = cnode; |
---|
| 1253 | return; |
---|
| 1254 | |
---|
| 1255 | } else { |
---|
| 1256 | Edge edge = node_data[order_map[cnode]].first; |
---|
| 1257 | |
---|
| 1258 | if (_ugraph.target(edge) == pred) { |
---|
| 1259 | edge = edge_lists[edge].next; |
---|
| 1260 | } |
---|
| 1261 | _kuratowski.set(edge, true); |
---|
| 1262 | |
---|
| 1263 | Node next = _ugraph.target(edge); |
---|
| 1264 | pred = cnode; cnode = next; |
---|
| 1265 | } |
---|
| 1266 | |
---|
| 1267 | } |
---|
| 1268 | |
---|
| 1269 | } |
---|
| 1270 | |
---|
| 1271 | void orientComponent(Node root, int rn, OrderMap& order_map, |
---|
| 1272 | PredMap& pred_map, NodeData& node_data, |
---|
| 1273 | EdgeLists& edge_lists, FlipMap& flip_map, |
---|
| 1274 | TypeMap& type_map) { |
---|
| 1275 | node_data[order_map[root]].first = node_data[rn].first; |
---|
| 1276 | type_map[root] = 1; |
---|
| 1277 | |
---|
| 1278 | std::vector<Node> st, qu; |
---|
| 1279 | |
---|
| 1280 | st.push_back(root); |
---|
| 1281 | while (!st.empty()) { |
---|
| 1282 | Node node = st.back(); |
---|
| 1283 | st.pop_back(); |
---|
| 1284 | qu.push_back(node); |
---|
| 1285 | |
---|
| 1286 | Edge edge = node_data[order_map[node]].first; |
---|
| 1287 | |
---|
| 1288 | if (type_map[_ugraph.target(edge)] == 0) { |
---|
| 1289 | st.push_back(_ugraph.target(edge)); |
---|
| 1290 | type_map[_ugraph.target(edge)] = 1; |
---|
| 1291 | } |
---|
| 1292 | |
---|
| 1293 | Edge last = edge, pred = edge; |
---|
| 1294 | edge = edge_lists[edge].next; |
---|
| 1295 | while (edge != last) { |
---|
| 1296 | |
---|
| 1297 | if (type_map[_ugraph.target(edge)] == 0) { |
---|
| 1298 | st.push_back(_ugraph.target(edge)); |
---|
| 1299 | type_map[_ugraph.target(edge)] = 1; |
---|
| 1300 | } |
---|
| 1301 | |
---|
| 1302 | Edge next = edge_lists[edge].next != pred ? |
---|
| 1303 | edge_lists[edge].next : edge_lists[edge].prev; |
---|
| 1304 | pred = edge; edge = next; |
---|
| 1305 | } |
---|
| 1306 | |
---|
| 1307 | } |
---|
| 1308 | |
---|
| 1309 | type_map[root] = 2; |
---|
| 1310 | flip_map[root] = false; |
---|
| 1311 | |
---|
| 1312 | for (int i = 1; i < int(qu.size()); ++i) { |
---|
| 1313 | |
---|
| 1314 | Node node = qu[i]; |
---|
| 1315 | |
---|
| 1316 | while (type_map[node] != 2) { |
---|
| 1317 | st.push_back(node); |
---|
| 1318 | type_map[node] = 2; |
---|
| 1319 | node = _ugraph.source(pred_map[node]); |
---|
| 1320 | } |
---|
| 1321 | |
---|
| 1322 | bool flip = flip_map[node]; |
---|
| 1323 | |
---|
| 1324 | while (!st.empty()) { |
---|
| 1325 | node = st.back(); |
---|
| 1326 | st.pop_back(); |
---|
| 1327 | |
---|
| 1328 | flip_map[node] = flip != flip_map[node]; |
---|
| 1329 | flip = flip_map[node]; |
---|
| 1330 | |
---|
| 1331 | if (flip) { |
---|
| 1332 | Edge edge = node_data[order_map[node]].first; |
---|
| 1333 | std::swap(edge_lists[edge].prev, edge_lists[edge].next); |
---|
| 1334 | edge = edge_lists[edge].prev; |
---|
| 1335 | std::swap(edge_lists[edge].prev, edge_lists[edge].next); |
---|
| 1336 | node_data[order_map[node]].first = edge; |
---|
| 1337 | } |
---|
| 1338 | } |
---|
| 1339 | } |
---|
| 1340 | |
---|
| 1341 | for (int i = 0; i < int(qu.size()); ++i) { |
---|
| 1342 | |
---|
| 1343 | Edge edge = node_data[order_map[qu[i]]].first; |
---|
| 1344 | Edge last = edge, pred = edge; |
---|
| 1345 | |
---|
| 1346 | edge = edge_lists[edge].next; |
---|
| 1347 | while (edge != last) { |
---|
| 1348 | |
---|
| 1349 | if (edge_lists[edge].next == pred) { |
---|
| 1350 | std::swap(edge_lists[edge].next, edge_lists[edge].prev); |
---|
| 1351 | } |
---|
| 1352 | pred = edge; edge = edge_lists[edge].next; |
---|
| 1353 | } |
---|
| 1354 | |
---|
| 1355 | } |
---|
| 1356 | } |
---|
| 1357 | |
---|
| 1358 | void setFaceFlags(Node root, Node wnode, Node ynode, Node xnode, |
---|
| 1359 | OrderMap& order_map, NodeData& node_data, |
---|
| 1360 | TypeMap& type_map) { |
---|
| 1361 | Node node = _ugraph.target(node_data[order_map[root]].first); |
---|
| 1362 | |
---|
| 1363 | while (node != ynode) { |
---|
| 1364 | type_map[node] = HIGHY; |
---|
| 1365 | node = _ugraph.target(node_data[order_map[node]].first); |
---|
| 1366 | } |
---|
| 1367 | |
---|
| 1368 | while (node != wnode) { |
---|
| 1369 | type_map[node] = LOWY; |
---|
| 1370 | node = _ugraph.target(node_data[order_map[node]].first); |
---|
| 1371 | } |
---|
| 1372 | |
---|
| 1373 | node = _ugraph.target(node_data[order_map[wnode]].first); |
---|
| 1374 | |
---|
| 1375 | while (node != xnode) { |
---|
| 1376 | type_map[node] = LOWX; |
---|
| 1377 | node = _ugraph.target(node_data[order_map[node]].first); |
---|
| 1378 | } |
---|
| 1379 | type_map[node] = LOWX; |
---|
| 1380 | |
---|
| 1381 | node = _ugraph.target(node_data[order_map[xnode]].first); |
---|
| 1382 | while (node != root) { |
---|
| 1383 | type_map[node] = HIGHX; |
---|
| 1384 | node = _ugraph.target(node_data[order_map[node]].first); |
---|
| 1385 | } |
---|
| 1386 | |
---|
| 1387 | type_map[wnode] = PERTINENT; |
---|
| 1388 | type_map[root] = ROOT; |
---|
| 1389 | } |
---|
| 1390 | |
---|
| 1391 | void findInternalPath(std::vector<Edge>& ipath, |
---|
| 1392 | Node wnode, Node root, TypeMap& type_map, |
---|
| 1393 | OrderMap& order_map, NodeData& node_data, |
---|
| 1394 | EdgeLists& edge_lists) { |
---|
| 1395 | std::vector<Edge> st; |
---|
| 1396 | |
---|
| 1397 | Node node = wnode; |
---|
| 1398 | |
---|
| 1399 | while (node != root) { |
---|
| 1400 | Edge edge = edge_lists[node_data[order_map[node]].first].next; |
---|
| 1401 | st.push_back(edge); |
---|
| 1402 | node = _ugraph.target(edge); |
---|
| 1403 | } |
---|
| 1404 | |
---|
| 1405 | while (true) { |
---|
| 1406 | Edge edge = st.back(); |
---|
| 1407 | if (type_map[_ugraph.target(edge)] == LOWX || |
---|
| 1408 | type_map[_ugraph.target(edge)] == HIGHX) { |
---|
| 1409 | break; |
---|
| 1410 | } |
---|
| 1411 | if (type_map[_ugraph.target(edge)] == 2) { |
---|
| 1412 | type_map[_ugraph.target(edge)] = 3; |
---|
| 1413 | |
---|
| 1414 | edge = edge_lists[_ugraph.oppositeEdge(edge)].next; |
---|
| 1415 | st.push_back(edge); |
---|
| 1416 | } else { |
---|
| 1417 | st.pop_back(); |
---|
| 1418 | edge = edge_lists[edge].next; |
---|
| 1419 | |
---|
| 1420 | while (_ugraph.oppositeEdge(edge) == st.back()) { |
---|
| 1421 | edge = st.back(); |
---|
| 1422 | st.pop_back(); |
---|
| 1423 | edge = edge_lists[edge].next; |
---|
| 1424 | } |
---|
| 1425 | st.push_back(edge); |
---|
| 1426 | } |
---|
| 1427 | } |
---|
| 1428 | |
---|
| 1429 | for (int i = 0; i < int(st.size()); ++i) { |
---|
| 1430 | if (type_map[_ugraph.target(st[i])] != LOWY && |
---|
| 1431 | type_map[_ugraph.target(st[i])] != HIGHY) { |
---|
| 1432 | for (; i < int(st.size()); ++i) { |
---|
| 1433 | ipath.push_back(st[i]); |
---|
| 1434 | } |
---|
| 1435 | } |
---|
| 1436 | } |
---|
| 1437 | } |
---|
| 1438 | |
---|
| 1439 | void setInternalFlags(std::vector<Edge>& ipath, TypeMap& type_map) { |
---|
| 1440 | for (int i = 1; i < int(ipath.size()); ++i) { |
---|
| 1441 | type_map[_ugraph.source(ipath[i])] = INTERNAL; |
---|
| 1442 | } |
---|
| 1443 | } |
---|
| 1444 | |
---|
| 1445 | void findPilePath(std::vector<Edge>& ppath, |
---|
| 1446 | Node root, TypeMap& type_map, OrderMap& order_map, |
---|
| 1447 | NodeData& node_data, EdgeLists& edge_lists) { |
---|
| 1448 | std::vector<Edge> st; |
---|
| 1449 | |
---|
| 1450 | st.push_back(_ugraph.oppositeEdge(node_data[order_map[root]].first)); |
---|
| 1451 | st.push_back(node_data[order_map[root]].first); |
---|
| 1452 | |
---|
| 1453 | while (st.size() > 1) { |
---|
| 1454 | Edge edge = st.back(); |
---|
| 1455 | if (type_map[_ugraph.target(edge)] == INTERNAL) { |
---|
| 1456 | break; |
---|
| 1457 | } |
---|
| 1458 | if (type_map[_ugraph.target(edge)] == 3) { |
---|
| 1459 | type_map[_ugraph.target(edge)] = 4; |
---|
| 1460 | |
---|
| 1461 | edge = edge_lists[_ugraph.oppositeEdge(edge)].next; |
---|
| 1462 | st.push_back(edge); |
---|
| 1463 | } else { |
---|
| 1464 | st.pop_back(); |
---|
| 1465 | edge = edge_lists[edge].next; |
---|
| 1466 | |
---|
| 1467 | while (!st.empty() && _ugraph.oppositeEdge(edge) == st.back()) { |
---|
| 1468 | edge = st.back(); |
---|
| 1469 | st.pop_back(); |
---|
| 1470 | edge = edge_lists[edge].next; |
---|
| 1471 | } |
---|
| 1472 | st.push_back(edge); |
---|
| 1473 | } |
---|
| 1474 | } |
---|
| 1475 | |
---|
| 1476 | for (int i = 1; i < int(st.size()); ++i) { |
---|
| 1477 | ppath.push_back(st[i]); |
---|
| 1478 | } |
---|
| 1479 | } |
---|
| 1480 | |
---|
| 1481 | |
---|
| 1482 | int markExternalPath(Node node, OrderMap& order_map, |
---|
| 1483 | ChildLists& child_lists, PredMap& pred_map, |
---|
| 1484 | AncestorMap& ancestor_map, LowMap& low_map) { |
---|
| 1485 | int lp = lowPoint(node, order_map, child_lists, |
---|
| 1486 | ancestor_map, low_map); |
---|
| 1487 | |
---|
| 1488 | if (ancestor_map[node] != lp) { |
---|
| 1489 | node = child_lists[node].first; |
---|
| 1490 | _kuratowski[pred_map[node]] = true; |
---|
| 1491 | |
---|
| 1492 | while (ancestor_map[node] != lp) { |
---|
| 1493 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
---|
| 1494 | Node tnode = _ugraph.target(e); |
---|
| 1495 | if (order_map[tnode] > order_map[node] && low_map[tnode] == lp) { |
---|
| 1496 | node = tnode; |
---|
| 1497 | _kuratowski[e] = true; |
---|
| 1498 | break; |
---|
| 1499 | } |
---|
| 1500 | } |
---|
| 1501 | } |
---|
| 1502 | } |
---|
| 1503 | |
---|
| 1504 | for (OutEdgeIt e(_ugraph, node); e != INVALID; ++e) { |
---|
| 1505 | if (order_map[_ugraph.target(e)] == lp) { |
---|
| 1506 | _kuratowski[e] = true; |
---|
| 1507 | break; |
---|
| 1508 | } |
---|
| 1509 | } |
---|
| 1510 | |
---|
| 1511 | return lp; |
---|
| 1512 | } |
---|
| 1513 | |
---|
| 1514 | void markPertinentPath(Node node, OrderMap& order_map, |
---|
| 1515 | NodeData& node_data, EdgeLists& edge_lists, |
---|
| 1516 | EmbedEdge& embed_edge, MergeRoots& merge_roots) { |
---|
| 1517 | while (embed_edge[node] == INVALID) { |
---|
| 1518 | int n = merge_roots[node].front(); |
---|
| 1519 | Edge edge = node_data[n].first; |
---|
| 1520 | |
---|
| 1521 | _kuratowski.set(edge, true); |
---|
| 1522 | |
---|
| 1523 | Node pred = node; |
---|
| 1524 | node = _ugraph.target(edge); |
---|
| 1525 | while (!pertinent(node, embed_edge, merge_roots)) { |
---|
| 1526 | edge = node_data[order_map[node]].first; |
---|
| 1527 | if (_ugraph.target(edge) == pred) { |
---|
| 1528 | edge = edge_lists[edge].next; |
---|
| 1529 | } |
---|
| 1530 | _kuratowski.set(edge, true); |
---|
| 1531 | pred = node; |
---|
| 1532 | node = _ugraph.target(edge); |
---|
| 1533 | } |
---|
| 1534 | } |
---|
| 1535 | _kuratowski.set(embed_edge[node], true); |
---|
| 1536 | } |
---|
| 1537 | |
---|
| 1538 | void markPredPath(Node node, Node snode, PredMap& pred_map) { |
---|
| 1539 | while (node != snode) { |
---|
| 1540 | _kuratowski.set(pred_map[node], true); |
---|
| 1541 | node = _ugraph.source(pred_map[node]); |
---|
| 1542 | } |
---|
| 1543 | } |
---|
| 1544 | |
---|
| 1545 | void markFacePath(Node ynode, Node xnode, |
---|
| 1546 | OrderMap& order_map, NodeData& node_data) { |
---|
| 1547 | Edge edge = node_data[order_map[ynode]].first; |
---|
| 1548 | Node node = _ugraph.target(edge); |
---|
| 1549 | _kuratowski.set(edge, true); |
---|
| 1550 | |
---|
| 1551 | while (node != xnode) { |
---|
| 1552 | edge = node_data[order_map[node]].first; |
---|
| 1553 | _kuratowski.set(edge, true); |
---|
| 1554 | node = _ugraph.target(edge); |
---|
| 1555 | } |
---|
| 1556 | } |
---|
| 1557 | |
---|
| 1558 | void markInternalPath(std::vector<Edge>& path) { |
---|
| 1559 | for (int i = 0; i < int(path.size()); ++i) { |
---|
| 1560 | _kuratowski.set(path[i], true); |
---|
| 1561 | } |
---|
| 1562 | } |
---|
| 1563 | |
---|
| 1564 | void markPilePath(std::vector<Edge>& path) { |
---|
| 1565 | for (int i = 0; i < int(path.size()); ++i) { |
---|
| 1566 | _kuratowski.set(path[i], true); |
---|
| 1567 | } |
---|
| 1568 | } |
---|
| 1569 | |
---|
| 1570 | void isolateKuratowski(Edge edge, NodeData& node_data, |
---|
| 1571 | EdgeLists& edge_lists, FlipMap& flip_map, |
---|
| 1572 | OrderMap& order_map, OrderList& order_list, |
---|
| 1573 | PredMap& pred_map, ChildLists& child_lists, |
---|
| 1574 | AncestorMap& ancestor_map, LowMap& low_map, |
---|
| 1575 | EmbedEdge& embed_edge, MergeRoots& merge_roots) { |
---|
| 1576 | |
---|
| 1577 | Node root = _ugraph.source(edge); |
---|
| 1578 | Node enode = _ugraph.target(edge); |
---|
| 1579 | |
---|
| 1580 | int rorder = order_map[root]; |
---|
| 1581 | |
---|
| 1582 | TypeMap type_map(_ugraph, 0); |
---|
| 1583 | |
---|
| 1584 | int rn = findComponentRoot(root, enode, child_lists, |
---|
| 1585 | order_map, order_list); |
---|
| 1586 | |
---|
| 1587 | Node xnode = order_list[node_data[rn].next]; |
---|
| 1588 | Node ynode = order_list[node_data[rn].prev]; |
---|
| 1589 | |
---|
| 1590 | // Minor-A |
---|
| 1591 | { |
---|
| 1592 | while (!merge_roots[xnode].empty() || !merge_roots[ynode].empty()) { |
---|
| 1593 | |
---|
| 1594 | if (!merge_roots[xnode].empty()) { |
---|
| 1595 | root = xnode; |
---|
| 1596 | rn = merge_roots[xnode].front(); |
---|
| 1597 | } else { |
---|
| 1598 | root = ynode; |
---|
| 1599 | rn = merge_roots[ynode].front(); |
---|
| 1600 | } |
---|
| 1601 | |
---|
| 1602 | xnode = order_list[node_data[rn].next]; |
---|
| 1603 | ynode = order_list[node_data[rn].prev]; |
---|
| 1604 | } |
---|
| 1605 | |
---|
| 1606 | if (root != _ugraph.source(edge)) { |
---|
| 1607 | orientComponent(root, rn, order_map, pred_map, |
---|
| 1608 | node_data, edge_lists, flip_map, type_map); |
---|
| 1609 | markFacePath(root, root, order_map, node_data); |
---|
| 1610 | int xlp = markExternalPath(xnode, order_map, child_lists, |
---|
| 1611 | pred_map, ancestor_map, low_map); |
---|
| 1612 | int ylp = markExternalPath(ynode, order_map, child_lists, |
---|
| 1613 | pred_map, ancestor_map, low_map); |
---|
| 1614 | markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map); |
---|
| 1615 | Node lwnode = findPertinent(ynode, order_map, node_data, |
---|
| 1616 | embed_edge, merge_roots); |
---|
| 1617 | |
---|
| 1618 | markPertinentPath(lwnode, order_map, node_data, edge_lists, |
---|
| 1619 | embed_edge, merge_roots); |
---|
| 1620 | |
---|
| 1621 | return; |
---|
| 1622 | } |
---|
| 1623 | } |
---|
| 1624 | |
---|
| 1625 | orientComponent(root, rn, order_map, pred_map, |
---|
| 1626 | node_data, edge_lists, flip_map, type_map); |
---|
| 1627 | |
---|
| 1628 | Node wnode = findPertinent(ynode, order_map, node_data, |
---|
| 1629 | embed_edge, merge_roots); |
---|
| 1630 | setFaceFlags(root, wnode, ynode, xnode, order_map, node_data, type_map); |
---|
| 1631 | |
---|
| 1632 | |
---|
| 1633 | //Minor-B |
---|
| 1634 | if (!merge_roots[wnode].empty()) { |
---|
| 1635 | int cn = merge_roots[wnode].back(); |
---|
| 1636 | Node rep = order_list[cn - order_list.size()]; |
---|
| 1637 | if (low_map[rep] < rorder) { |
---|
| 1638 | markFacePath(root, root, order_map, node_data); |
---|
| 1639 | int xlp = markExternalPath(xnode, order_map, child_lists, |
---|
| 1640 | pred_map, ancestor_map, low_map); |
---|
| 1641 | int ylp = markExternalPath(ynode, order_map, child_lists, |
---|
| 1642 | pred_map, ancestor_map, low_map); |
---|
| 1643 | |
---|
| 1644 | Node lwnode, lznode; |
---|
| 1645 | markCommonPath(wnode, rorder, lwnode, lznode, order_list, |
---|
| 1646 | order_map, node_data, edge_lists, embed_edge, |
---|
| 1647 | merge_roots, child_lists, ancestor_map, low_map); |
---|
| 1648 | |
---|
| 1649 | markPertinentPath(lwnode, order_map, node_data, edge_lists, |
---|
| 1650 | embed_edge, merge_roots); |
---|
| 1651 | int zlp = markExternalPath(lznode, order_map, child_lists, |
---|
| 1652 | pred_map, ancestor_map, low_map); |
---|
| 1653 | |
---|
| 1654 | int minlp = xlp < ylp ? xlp : ylp; |
---|
| 1655 | if (zlp < minlp) minlp = zlp; |
---|
| 1656 | |
---|
| 1657 | int maxlp = xlp > ylp ? xlp : ylp; |
---|
| 1658 | if (zlp > maxlp) maxlp = zlp; |
---|
| 1659 | |
---|
| 1660 | markPredPath(order_list[maxlp], order_list[minlp], pred_map); |
---|
| 1661 | |
---|
| 1662 | return; |
---|
| 1663 | } |
---|
| 1664 | } |
---|
| 1665 | |
---|
| 1666 | Node pxnode, pynode; |
---|
| 1667 | std::vector<Edge> ipath; |
---|
| 1668 | findInternalPath(ipath, wnode, root, type_map, order_map, |
---|
| 1669 | node_data, edge_lists); |
---|
| 1670 | setInternalFlags(ipath, type_map); |
---|
| 1671 | pynode = _ugraph.source(ipath.front()); |
---|
| 1672 | pxnode = _ugraph.target(ipath.back()); |
---|
| 1673 | |
---|
| 1674 | wnode = findPertinent(pynode, order_map, node_data, |
---|
| 1675 | embed_edge, merge_roots); |
---|
| 1676 | |
---|
| 1677 | // Minor-C |
---|
| 1678 | { |
---|
| 1679 | if (type_map[_ugraph.source(ipath.front())] == HIGHY) { |
---|
| 1680 | if (type_map[_ugraph.target(ipath.back())] == HIGHX) { |
---|
| 1681 | markFacePath(xnode, pxnode, order_map, node_data); |
---|
| 1682 | } |
---|
| 1683 | markFacePath(root, xnode, order_map, node_data); |
---|
| 1684 | markPertinentPath(wnode, order_map, node_data, edge_lists, |
---|
| 1685 | embed_edge, merge_roots); |
---|
| 1686 | markInternalPath(ipath); |
---|
| 1687 | int xlp = markExternalPath(xnode, order_map, child_lists, |
---|
| 1688 | pred_map, ancestor_map, low_map); |
---|
| 1689 | int ylp = markExternalPath(ynode, order_map, child_lists, |
---|
| 1690 | pred_map, ancestor_map, low_map); |
---|
| 1691 | markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map); |
---|
| 1692 | return; |
---|
| 1693 | } |
---|
| 1694 | |
---|
| 1695 | if (type_map[_ugraph.target(ipath.back())] == HIGHX) { |
---|
| 1696 | markFacePath(ynode, root, order_map, node_data); |
---|
| 1697 | markPertinentPath(wnode, order_map, node_data, edge_lists, |
---|
| 1698 | embed_edge, merge_roots); |
---|
| 1699 | markInternalPath(ipath); |
---|
| 1700 | int xlp = markExternalPath(xnode, order_map, child_lists, |
---|
| 1701 | pred_map, ancestor_map, low_map); |
---|
| 1702 | int ylp = markExternalPath(ynode, order_map, child_lists, |
---|
| 1703 | pred_map, ancestor_map, low_map); |
---|
| 1704 | markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map); |
---|
| 1705 | return; |
---|
| 1706 | } |
---|
| 1707 | } |
---|
| 1708 | |
---|
| 1709 | std::vector<Edge> ppath; |
---|
| 1710 | findPilePath(ppath, root, type_map, order_map, node_data, edge_lists); |
---|
| 1711 | |
---|
| 1712 | // Minor-D |
---|
| 1713 | if (!ppath.empty()) { |
---|
| 1714 | markFacePath(ynode, xnode, order_map, node_data); |
---|
| 1715 | markPertinentPath(wnode, order_map, node_data, edge_lists, |
---|
| 1716 | embed_edge, merge_roots); |
---|
| 1717 | markPilePath(ppath); |
---|
| 1718 | markInternalPath(ipath); |
---|
| 1719 | int xlp = markExternalPath(xnode, order_map, child_lists, |
---|
| 1720 | pred_map, ancestor_map, low_map); |
---|
| 1721 | int ylp = markExternalPath(ynode, order_map, child_lists, |
---|
| 1722 | pred_map, ancestor_map, low_map); |
---|
| 1723 | markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map); |
---|
| 1724 | return; |
---|
| 1725 | } |
---|
| 1726 | |
---|
| 1727 | // Minor-E* |
---|
| 1728 | { |
---|
| 1729 | |
---|
| 1730 | if (!external(wnode, rorder, child_lists, ancestor_map, low_map)) { |
---|
| 1731 | Node znode = findExternal(pynode, rorder, order_map, |
---|
| 1732 | child_lists, ancestor_map, |
---|
| 1733 | low_map, node_data); |
---|
| 1734 | |
---|
| 1735 | if (type_map[znode] == LOWY) { |
---|
| 1736 | markFacePath(root, xnode, order_map, node_data); |
---|
| 1737 | markPertinentPath(wnode, order_map, node_data, edge_lists, |
---|
| 1738 | embed_edge, merge_roots); |
---|
| 1739 | markInternalPath(ipath); |
---|
| 1740 | int xlp = markExternalPath(xnode, order_map, child_lists, |
---|
| 1741 | pred_map, ancestor_map, low_map); |
---|
| 1742 | int zlp = markExternalPath(znode, order_map, child_lists, |
---|
| 1743 | pred_map, ancestor_map, low_map); |
---|
| 1744 | markPredPath(root, order_list[xlp < zlp ? xlp : zlp], pred_map); |
---|
| 1745 | } else { |
---|
| 1746 | markFacePath(ynode, root, order_map, node_data); |
---|
| 1747 | markPertinentPath(wnode, order_map, node_data, edge_lists, |
---|
| 1748 | embed_edge, merge_roots); |
---|
| 1749 | markInternalPath(ipath); |
---|
| 1750 | int ylp = markExternalPath(ynode, order_map, child_lists, |
---|
| 1751 | pred_map, ancestor_map, low_map); |
---|
| 1752 | int zlp = markExternalPath(znode, order_map, child_lists, |
---|
| 1753 | pred_map, ancestor_map, low_map); |
---|
| 1754 | markPredPath(root, order_list[ylp < zlp ? ylp : zlp], pred_map); |
---|
| 1755 | } |
---|
| 1756 | return; |
---|
| 1757 | } |
---|
| 1758 | |
---|
| 1759 | int xlp = markExternalPath(xnode, order_map, child_lists, |
---|
| 1760 | pred_map, ancestor_map, low_map); |
---|
| 1761 | int ylp = markExternalPath(ynode, order_map, child_lists, |
---|
| 1762 | pred_map, ancestor_map, low_map); |
---|
| 1763 | int wlp = markExternalPath(wnode, order_map, child_lists, |
---|
| 1764 | pred_map, ancestor_map, low_map); |
---|
| 1765 | |
---|
| 1766 | if (wlp > xlp && wlp > ylp) { |
---|
| 1767 | markFacePath(root, root, order_map, node_data); |
---|
| 1768 | markPredPath(root, order_list[xlp < ylp ? xlp : ylp], pred_map); |
---|
| 1769 | return; |
---|
| 1770 | } |
---|
| 1771 | |
---|
| 1772 | markInternalPath(ipath); |
---|
| 1773 | markPertinentPath(wnode, order_map, node_data, edge_lists, |
---|
| 1774 | embed_edge, merge_roots); |
---|
| 1775 | |
---|
| 1776 | if (xlp > ylp && xlp > wlp) { |
---|
| 1777 | markFacePath(root, pynode, order_map, node_data); |
---|
| 1778 | markFacePath(wnode, xnode, order_map, node_data); |
---|
| 1779 | markPredPath(root, order_list[ylp < wlp ? ylp : wlp], pred_map); |
---|
| 1780 | return; |
---|
| 1781 | } |
---|
| 1782 | |
---|
| 1783 | if (ylp > xlp && ylp > wlp) { |
---|
| 1784 | markFacePath(pxnode, root, order_map, node_data); |
---|
| 1785 | markFacePath(ynode, wnode, order_map, node_data); |
---|
| 1786 | markPredPath(root, order_list[xlp < wlp ? xlp : wlp], pred_map); |
---|
| 1787 | return; |
---|
| 1788 | } |
---|
| 1789 | |
---|
| 1790 | if (pynode != ynode) { |
---|
| 1791 | markFacePath(pxnode, wnode, order_map, node_data); |
---|
| 1792 | |
---|
| 1793 | int minlp = xlp < ylp ? xlp : ylp; |
---|
| 1794 | if (wlp < minlp) minlp = wlp; |
---|
| 1795 | |
---|
| 1796 | int maxlp = xlp > ylp ? xlp : ylp; |
---|
| 1797 | if (wlp > maxlp) maxlp = wlp; |
---|
| 1798 | |
---|
| 1799 | markPredPath(order_list[maxlp], order_list[minlp], pred_map); |
---|
| 1800 | return; |
---|
| 1801 | } |
---|
| 1802 | |
---|
| 1803 | if (pxnode != xnode) { |
---|
| 1804 | markFacePath(wnode, pynode, order_map, node_data); |
---|
| 1805 | |
---|
| 1806 | int minlp = xlp < ylp ? xlp : ylp; |
---|
| 1807 | if (wlp < minlp) minlp = wlp; |
---|
| 1808 | |
---|
| 1809 | int maxlp = xlp > ylp ? xlp : ylp; |
---|
| 1810 | if (wlp > maxlp) maxlp = wlp; |
---|
| 1811 | |
---|
| 1812 | markPredPath(order_list[maxlp], order_list[minlp], pred_map); |
---|
| 1813 | return; |
---|
| 1814 | } |
---|
| 1815 | |
---|
| 1816 | markFacePath(root, root, order_map, node_data); |
---|
| 1817 | int minlp = xlp < ylp ? xlp : ylp; |
---|
| 1818 | if (wlp < minlp) minlp = wlp; |
---|
| 1819 | markPredPath(root, order_list[minlp], pred_map); |
---|
| 1820 | return; |
---|
| 1821 | } |
---|
| 1822 | |
---|
| 1823 | } |
---|
| 1824 | |
---|
| 1825 | }; |
---|
| 1826 | |
---|
[2499] | 1827 | namespace _planarity_bits { |
---|
| 1828 | |
---|
| 1829 | template <typename UGraph, typename EmbeddingMap> |
---|
| 1830 | void makeConnected(UGraph& ugraph, EmbeddingMap& embedding) { |
---|
| 1831 | DfsVisitor<UGraph> null_visitor; |
---|
| 1832 | DfsVisit<UGraph, DfsVisitor<UGraph> > dfs(ugraph, null_visitor); |
---|
| 1833 | dfs.init(); |
---|
| 1834 | |
---|
| 1835 | typename UGraph::Node u = INVALID; |
---|
| 1836 | for (typename UGraph::NodeIt n(ugraph); n != INVALID; ++n) { |
---|
| 1837 | if (!dfs.reached(n)) { |
---|
| 1838 | dfs.addSource(n); |
---|
| 1839 | dfs.start(); |
---|
| 1840 | if (u == INVALID) { |
---|
| 1841 | u = n; |
---|
| 1842 | } else { |
---|
| 1843 | typename UGraph::Node v = n; |
---|
| 1844 | |
---|
| 1845 | typename UGraph::Edge ue = typename UGraph::OutEdgeIt(ugraph, u); |
---|
| 1846 | typename UGraph::Edge ve = typename UGraph::OutEdgeIt(ugraph, v); |
---|
| 1847 | |
---|
| 1848 | typename UGraph::Edge e = ugraph.direct(ugraph.addEdge(u, v), true); |
---|
| 1849 | |
---|
| 1850 | if (ue != INVALID) { |
---|
| 1851 | embedding[e] = embedding[ue]; |
---|
| 1852 | embedding[ue] = e; |
---|
| 1853 | } else { |
---|
| 1854 | embedding[e] = e; |
---|
| 1855 | } |
---|
| 1856 | |
---|
| 1857 | if (ve != INVALID) { |
---|
| 1858 | embedding[ugraph.oppositeEdge(e)] = embedding[ve]; |
---|
| 1859 | embedding[ve] = ugraph.oppositeEdge(e); |
---|
| 1860 | } else { |
---|
| 1861 | embedding[ugraph.oppositeEdge(e)] = ugraph.oppositeEdge(e); |
---|
| 1862 | } |
---|
| 1863 | } |
---|
| 1864 | } |
---|
| 1865 | } |
---|
| 1866 | } |
---|
| 1867 | |
---|
| 1868 | template <typename UGraph, typename EmbeddingMap> |
---|
| 1869 | void makeBiNodeConnected(UGraph& ugraph, EmbeddingMap& embedding) { |
---|
| 1870 | typename UGraph::template EdgeMap<bool> processed(ugraph); |
---|
| 1871 | |
---|
| 1872 | std::vector<typename UGraph::Edge> edges; |
---|
| 1873 | for (typename UGraph::EdgeIt e(ugraph); e != INVALID; ++e) { |
---|
| 1874 | edges.push_back(e); |
---|
| 1875 | } |
---|
| 1876 | |
---|
| 1877 | IterableBoolMap<UGraph, typename UGraph::Node> visited(ugraph, false); |
---|
| 1878 | |
---|
| 1879 | for (int i = 0; i < int(edges.size()); ++i) { |
---|
| 1880 | typename UGraph::Edge pp = edges[i]; |
---|
| 1881 | if (processed[pp]) continue; |
---|
| 1882 | |
---|
| 1883 | typename UGraph::Edge e = embedding[ugraph.oppositeEdge(pp)]; |
---|
| 1884 | processed[e] = true; |
---|
| 1885 | visited.set(ugraph.source(e), true); |
---|
| 1886 | |
---|
| 1887 | typename UGraph::Edge p = e, l = e; |
---|
| 1888 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 1889 | |
---|
| 1890 | while (e != l) { |
---|
| 1891 | processed[e] = true; |
---|
| 1892 | |
---|
| 1893 | if (visited[ugraph.source(e)]) { |
---|
| 1894 | |
---|
| 1895 | typename UGraph::Edge n = |
---|
| 1896 | ugraph.direct(ugraph.addEdge(ugraph.source(p), |
---|
| 1897 | ugraph.target(e)), true); |
---|
| 1898 | embedding[n] = p; |
---|
| 1899 | embedding[ugraph.oppositeEdge(pp)] = n; |
---|
| 1900 | |
---|
| 1901 | embedding[ugraph.oppositeEdge(n)] = |
---|
| 1902 | embedding[ugraph.oppositeEdge(e)]; |
---|
| 1903 | embedding[ugraph.oppositeEdge(e)] = |
---|
| 1904 | ugraph.oppositeEdge(n); |
---|
| 1905 | |
---|
| 1906 | p = n; |
---|
| 1907 | e = embedding[ugraph.oppositeEdge(n)]; |
---|
| 1908 | } else { |
---|
| 1909 | visited.set(ugraph.source(e), true); |
---|
| 1910 | pp = p; |
---|
| 1911 | p = e; |
---|
| 1912 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 1913 | } |
---|
| 1914 | } |
---|
| 1915 | visited.setAll(false); |
---|
| 1916 | } |
---|
| 1917 | } |
---|
| 1918 | |
---|
| 1919 | |
---|
| 1920 | template <typename UGraph, typename EmbeddingMap> |
---|
| 1921 | void makeMaxPlanar(UGraph& ugraph, EmbeddingMap& embedding) { |
---|
| 1922 | |
---|
| 1923 | typename UGraph::template NodeMap<int> degree(ugraph); |
---|
| 1924 | |
---|
| 1925 | for (typename UGraph::NodeIt n(ugraph); n != INVALID; ++n) { |
---|
| 1926 | degree[n] = countIncEdges(ugraph, n); |
---|
| 1927 | } |
---|
| 1928 | |
---|
| 1929 | typename UGraph::template EdgeMap<bool> processed(ugraph); |
---|
| 1930 | IterableBoolMap<UGraph, typename UGraph::Node> visited(ugraph, false); |
---|
| 1931 | |
---|
| 1932 | std::vector<typename UGraph::Edge> edges; |
---|
| 1933 | for (typename UGraph::EdgeIt e(ugraph); e != INVALID; ++e) { |
---|
| 1934 | edges.push_back(e); |
---|
| 1935 | } |
---|
| 1936 | |
---|
| 1937 | for (int i = 0; i < int(edges.size()); ++i) { |
---|
| 1938 | typename UGraph::Edge e = edges[i]; |
---|
| 1939 | |
---|
| 1940 | if (processed[e]) continue; |
---|
| 1941 | processed[e] = true; |
---|
| 1942 | |
---|
| 1943 | typename UGraph::Edge mine = e; |
---|
| 1944 | int mind = degree[ugraph.source(e)]; |
---|
| 1945 | |
---|
| 1946 | int face_size = 1; |
---|
| 1947 | |
---|
| 1948 | typename UGraph::Edge l = e; |
---|
| 1949 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 1950 | while (l != e) { |
---|
| 1951 | processed[e] = true; |
---|
| 1952 | |
---|
| 1953 | ++face_size; |
---|
| 1954 | |
---|
| 1955 | if (degree[ugraph.source(e)] < mind) { |
---|
| 1956 | mine = e; |
---|
| 1957 | mind = degree[ugraph.source(e)]; |
---|
| 1958 | } |
---|
| 1959 | |
---|
| 1960 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 1961 | } |
---|
| 1962 | |
---|
| 1963 | if (face_size < 4) { |
---|
| 1964 | continue; |
---|
| 1965 | } |
---|
| 1966 | |
---|
| 1967 | typename UGraph::Node s = ugraph.source(mine); |
---|
| 1968 | for (typename UGraph::OutEdgeIt e(ugraph, s); e != INVALID; ++e) { |
---|
| 1969 | visited.set(ugraph.target(e), true); |
---|
| 1970 | } |
---|
| 1971 | |
---|
| 1972 | typename UGraph::Edge oppe = INVALID; |
---|
| 1973 | |
---|
| 1974 | e = embedding[ugraph.oppositeEdge(mine)]; |
---|
| 1975 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 1976 | while (ugraph.target(e) != s) { |
---|
| 1977 | if (visited[ugraph.source(e)]) { |
---|
| 1978 | oppe = e; |
---|
| 1979 | break; |
---|
| 1980 | } |
---|
| 1981 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 1982 | } |
---|
| 1983 | visited.setAll(false); |
---|
| 1984 | |
---|
| 1985 | if (oppe == INVALID) { |
---|
| 1986 | |
---|
| 1987 | e = embedding[ugraph.oppositeEdge(mine)]; |
---|
| 1988 | typename UGraph::Edge pn = mine, p = e; |
---|
| 1989 | |
---|
| 1990 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 1991 | while (ugraph.target(e) != s) { |
---|
| 1992 | typename UGraph::Edge n = |
---|
| 1993 | ugraph.direct(ugraph.addEdge(s, ugraph.source(e)), true); |
---|
| 1994 | |
---|
| 1995 | embedding[n] = pn; |
---|
| 1996 | embedding[ugraph.oppositeEdge(n)] = e; |
---|
| 1997 | embedding[ugraph.oppositeEdge(p)] = ugraph.oppositeEdge(n); |
---|
| 1998 | |
---|
| 1999 | pn = n; |
---|
| 2000 | |
---|
| 2001 | p = e; |
---|
| 2002 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 2003 | } |
---|
| 2004 | |
---|
| 2005 | embedding[ugraph.oppositeEdge(e)] = pn; |
---|
| 2006 | |
---|
| 2007 | } else { |
---|
| 2008 | |
---|
| 2009 | mine = embedding[ugraph.oppositeEdge(mine)]; |
---|
| 2010 | s = ugraph.source(mine); |
---|
| 2011 | oppe = embedding[ugraph.oppositeEdge(oppe)]; |
---|
| 2012 | typename UGraph::Node t = ugraph.source(oppe); |
---|
| 2013 | |
---|
| 2014 | typename UGraph::Edge ce = ugraph.direct(ugraph.addEdge(s, t), true); |
---|
| 2015 | embedding[ce] = mine; |
---|
| 2016 | embedding[ugraph.oppositeEdge(ce)] = oppe; |
---|
| 2017 | |
---|
| 2018 | typename UGraph::Edge pn = ce, p = oppe; |
---|
| 2019 | e = embedding[ugraph.oppositeEdge(oppe)]; |
---|
| 2020 | while (ugraph.target(e) != s) { |
---|
| 2021 | typename UGraph::Edge n = |
---|
| 2022 | ugraph.direct(ugraph.addEdge(s, ugraph.source(e)), true); |
---|
| 2023 | |
---|
| 2024 | embedding[n] = pn; |
---|
| 2025 | embedding[ugraph.oppositeEdge(n)] = e; |
---|
| 2026 | embedding[ugraph.oppositeEdge(p)] = ugraph.oppositeEdge(n); |
---|
| 2027 | |
---|
| 2028 | pn = n; |
---|
| 2029 | |
---|
| 2030 | p = e; |
---|
| 2031 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 2032 | |
---|
| 2033 | } |
---|
| 2034 | embedding[ugraph.oppositeEdge(e)] = pn; |
---|
| 2035 | |
---|
| 2036 | pn = ugraph.oppositeEdge(ce), p = mine; |
---|
| 2037 | e = embedding[ugraph.oppositeEdge(mine)]; |
---|
| 2038 | while (ugraph.target(e) != t) { |
---|
| 2039 | typename UGraph::Edge n = |
---|
| 2040 | ugraph.direct(ugraph.addEdge(t, ugraph.source(e)), true); |
---|
| 2041 | |
---|
| 2042 | embedding[n] = pn; |
---|
| 2043 | embedding[ugraph.oppositeEdge(n)] = e; |
---|
| 2044 | embedding[ugraph.oppositeEdge(p)] = ugraph.oppositeEdge(n); |
---|
| 2045 | |
---|
| 2046 | pn = n; |
---|
| 2047 | |
---|
| 2048 | p = e; |
---|
| 2049 | e = embedding[ugraph.oppositeEdge(e)]; |
---|
| 2050 | |
---|
| 2051 | } |
---|
| 2052 | embedding[ugraph.oppositeEdge(e)] = pn; |
---|
| 2053 | } |
---|
| 2054 | } |
---|
| 2055 | } |
---|
| 2056 | |
---|
| 2057 | } |
---|
| 2058 | |
---|
[2500] | 2059 | /// \ingroup planar |
---|
| 2060 | /// |
---|
[2499] | 2061 | /// \brief Schnyder's planar drawing algorithms |
---|
| 2062 | /// |
---|
| 2063 | /// The planar drawing algorithm calculates location for each node |
---|
| 2064 | /// in the plane, which coordinates satisfies that if each edge is |
---|
| 2065 | /// represented with a straight line then the edges will not |
---|
| 2066 | /// intersect each other. |
---|
| 2067 | /// |
---|
| 2068 | /// Scnyder's algorithm embeds the graph on \c (n-2,n-2) size grid, |
---|
| 2069 | /// ie. each node will be located in the \c [0,n-2]x[0,n-2] square. |
---|
| 2070 | /// The time complexity of the algorithm is O(n). |
---|
| 2071 | template <typename UGraph> |
---|
| 2072 | class PlanarDrawing { |
---|
| 2073 | public: |
---|
| 2074 | |
---|
| 2075 | UGRAPH_TYPEDEFS(typename UGraph); |
---|
| 2076 | |
---|
| 2077 | /// \brief The point type for store coordinates |
---|
| 2078 | typedef dim2::Point<int> Point; |
---|
| 2079 | /// \brief The map type for store coordinates |
---|
| 2080 | typedef typename UGraph::template NodeMap<Point> PointMap; |
---|
| 2081 | |
---|
| 2082 | |
---|
| 2083 | /// \brief Constructor |
---|
| 2084 | /// |
---|
| 2085 | /// Constructor |
---|
| 2086 | /// \pre The ugraph should be simple, ie. loop and parallel edge free. |
---|
| 2087 | PlanarDrawing(const UGraph& ugraph) |
---|
| 2088 | : _ugraph(ugraph), _point_map(ugraph) {} |
---|
| 2089 | |
---|
| 2090 | private: |
---|
| 2091 | |
---|
| 2092 | template <typename AuxUGraph, typename AuxEmbeddingMap> |
---|
| 2093 | void drawing(const AuxUGraph& ugraph, |
---|
| 2094 | const AuxEmbeddingMap& next, |
---|
| 2095 | PointMap& point_map) { |
---|
| 2096 | UGRAPH_TYPEDEFS(typename AuxUGraph); |
---|
| 2097 | |
---|
| 2098 | typename AuxUGraph::template EdgeMap<Edge> prev(ugraph); |
---|
| 2099 | |
---|
| 2100 | for (NodeIt n(ugraph); n != INVALID; ++n) { |
---|
| 2101 | Edge e = OutEdgeIt(ugraph, n); |
---|
| 2102 | |
---|
| 2103 | Edge p = e, l = e; |
---|
| 2104 | |
---|
| 2105 | e = next[e]; |
---|
| 2106 | while (e != l) { |
---|
| 2107 | prev[e] = p; |
---|
| 2108 | p = e; |
---|
| 2109 | e = next[e]; |
---|
| 2110 | } |
---|
| 2111 | prev[e] = p; |
---|
| 2112 | } |
---|
| 2113 | |
---|
| 2114 | Node anode, bnode, cnode; |
---|
| 2115 | |
---|
| 2116 | { |
---|
| 2117 | Edge e = EdgeIt(ugraph); |
---|
| 2118 | anode = ugraph.source(e); |
---|
| 2119 | bnode = ugraph.target(e); |
---|
| 2120 | cnode = ugraph.target(next[ugraph.oppositeEdge(e)]); |
---|
| 2121 | } |
---|
| 2122 | |
---|
| 2123 | IterableBoolMap<AuxUGraph, Node> proper(ugraph, false); |
---|
| 2124 | typename AuxUGraph::template NodeMap<int> conn(ugraph, -1); |
---|
| 2125 | |
---|
| 2126 | conn[anode] = conn[bnode] = -2; |
---|
| 2127 | { |
---|
| 2128 | for (OutEdgeIt e(ugraph, anode); e != INVALID; ++e) { |
---|
| 2129 | Node m = ugraph.target(e); |
---|
| 2130 | if (conn[m] == -1) { |
---|
| 2131 | conn[m] = 1; |
---|
| 2132 | } |
---|
| 2133 | } |
---|
| 2134 | conn[cnode] = 2; |
---|
| 2135 | |
---|
| 2136 | for (OutEdgeIt e(ugraph, bnode); e != INVALID; ++e) { |
---|
| 2137 | Node m = ugraph.target(e); |
---|
| 2138 | if (conn[m] == -1) { |
---|
| 2139 | conn[m] = 1; |
---|
| 2140 | } else if (conn[m] != -2) { |
---|
| 2141 | conn[m] += 1; |
---|
| 2142 | Edge pe = ugraph.oppositeEdge(e); |
---|
| 2143 | if (conn[ugraph.target(next[pe])] == -2) { |
---|
| 2144 | conn[m] -= 1; |
---|
| 2145 | } |
---|
| 2146 | if (conn[ugraph.target(prev[pe])] == -2) { |
---|
| 2147 | conn[m] -= 1; |
---|
| 2148 | } |
---|
| 2149 | |
---|
| 2150 | proper.set(m, conn[m] == 1); |
---|
| 2151 | } |
---|
| 2152 | } |
---|
| 2153 | } |
---|
| 2154 | |
---|
| 2155 | |
---|
| 2156 | typename AuxUGraph::template EdgeMap<int> angle(ugraph, -1); |
---|
| 2157 | |
---|
| 2158 | while (proper.trueNum() != 0) { |
---|
| 2159 | Node n = typename IterableBoolMap<AuxUGraph, Node>::TrueIt(proper); |
---|
| 2160 | proper.set(n, false); |
---|
| 2161 | conn[n] = -2; |
---|
| 2162 | |
---|
| 2163 | for (OutEdgeIt e(ugraph, n); e != INVALID; ++e) { |
---|
| 2164 | Node m = ugraph.target(e); |
---|
| 2165 | if (conn[m] == -1) { |
---|
| 2166 | conn[m] = 1; |
---|
| 2167 | } else if (conn[m] != -2) { |
---|
| 2168 | conn[m] += 1; |
---|
| 2169 | Edge pe = ugraph.oppositeEdge(e); |
---|
| 2170 | if (conn[ugraph.target(next[pe])] == -2) { |
---|
| 2171 | conn[m] -= 1; |
---|
| 2172 | } |
---|
| 2173 | if (conn[ugraph.target(prev[pe])] == -2) { |
---|
| 2174 | conn[m] -= 1; |
---|
| 2175 | } |
---|
| 2176 | |
---|
| 2177 | proper.set(m, conn[m] == 1); |
---|
| 2178 | } |
---|
| 2179 | } |
---|
| 2180 | |
---|
| 2181 | { |
---|
| 2182 | Edge e = OutEdgeIt(ugraph, n); |
---|
| 2183 | Edge p = e, l = e; |
---|
| 2184 | |
---|
| 2185 | e = next[e]; |
---|
| 2186 | while (e != l) { |
---|
| 2187 | |
---|
| 2188 | if (conn[ugraph.target(e)] == -2 && conn[ugraph.target(p)] == -2) { |
---|
| 2189 | Edge f = e; |
---|
| 2190 | angle[f] = 0; |
---|
| 2191 | f = next[ugraph.oppositeEdge(f)]; |
---|
| 2192 | angle[f] = 1; |
---|
| 2193 | f = next[ugraph.oppositeEdge(f)]; |
---|
| 2194 | angle[f] = 2; |
---|
| 2195 | } |
---|
| 2196 | |
---|
| 2197 | p = e; |
---|
| 2198 | e = next[e]; |
---|
| 2199 | } |
---|
| 2200 | |
---|
| 2201 | if (conn[ugraph.target(e)] == -2 && conn[ugraph.target(p)] == -2) { |
---|
| 2202 | Edge f = e; |
---|
| 2203 | angle[f] = 0; |
---|
| 2204 | f = next[ugraph.oppositeEdge(f)]; |
---|
| 2205 | angle[f] = 1; |
---|
| 2206 | f = next[ugraph.oppositeEdge(f)]; |
---|
| 2207 | angle[f] = 2; |
---|
| 2208 | } |
---|
| 2209 | } |
---|
| 2210 | } |
---|
| 2211 | |
---|
| 2212 | typename AuxUGraph::template NodeMap<Node> apred(ugraph, INVALID); |
---|
| 2213 | typename AuxUGraph::template NodeMap<Node> bpred(ugraph, INVALID); |
---|
| 2214 | typename AuxUGraph::template NodeMap<Node> cpred(ugraph, INVALID); |
---|
| 2215 | |
---|
| 2216 | typename AuxUGraph::template NodeMap<int> apredid(ugraph, -1); |
---|
| 2217 | typename AuxUGraph::template NodeMap<int> bpredid(ugraph, -1); |
---|
| 2218 | typename AuxUGraph::template NodeMap<int> cpredid(ugraph, -1); |
---|
| 2219 | |
---|
| 2220 | for (EdgeIt e(ugraph); e != INVALID; ++e) { |
---|
| 2221 | if (angle[e] == angle[next[e]]) { |
---|
| 2222 | switch (angle[e]) { |
---|
| 2223 | case 2: |
---|
| 2224 | apred[ugraph.target(e)] = ugraph.source(e); |
---|
| 2225 | apredid[ugraph.target(e)] = ugraph.id(ugraph.source(e)); |
---|
| 2226 | break; |
---|
| 2227 | case 1: |
---|
| 2228 | bpred[ugraph.target(e)] = ugraph.source(e); |
---|
| 2229 | bpredid[ugraph.target(e)] = ugraph.id(ugraph.source(e)); |
---|
| 2230 | break; |
---|
| 2231 | case 0: |
---|
| 2232 | cpred[ugraph.target(e)] = ugraph.source(e); |
---|
| 2233 | cpredid[ugraph.target(e)] = ugraph.id(ugraph.source(e)); |
---|
| 2234 | break; |
---|
| 2235 | } |
---|
| 2236 | } |
---|
| 2237 | } |
---|
| 2238 | |
---|
| 2239 | cpred[anode] = INVALID; |
---|
| 2240 | cpred[bnode] = INVALID; |
---|
| 2241 | |
---|
| 2242 | std::vector<Node> aorder, border, corder; |
---|
| 2243 | |
---|
| 2244 | { |
---|
| 2245 | typename AuxUGraph::template NodeMap<bool> processed(ugraph, false); |
---|
| 2246 | std::vector<Node> st; |
---|
| 2247 | for (NodeIt n(ugraph); n != INVALID; ++n) { |
---|
| 2248 | if (!processed[n] && n != bnode && n != cnode) { |
---|
| 2249 | st.push_back(n); |
---|
| 2250 | processed[n] = true; |
---|
| 2251 | Node m = apred[n]; |
---|
| 2252 | while (m != INVALID && !processed[m]) { |
---|
| 2253 | st.push_back(m); |
---|
| 2254 | processed[m] = true; |
---|
| 2255 | m = apred[m]; |
---|
| 2256 | } |
---|
| 2257 | while (!st.empty()) { |
---|
| 2258 | aorder.push_back(st.back()); |
---|
| 2259 | st.pop_back(); |
---|
| 2260 | } |
---|
| 2261 | } |
---|
| 2262 | } |
---|
| 2263 | } |
---|
| 2264 | |
---|
| 2265 | { |
---|
| 2266 | typename AuxUGraph::template NodeMap<bool> processed(ugraph, false); |
---|
| 2267 | std::vector<Node> st; |
---|
| 2268 | for (NodeIt n(ugraph); n != INVALID; ++n) { |
---|
| 2269 | if (!processed[n] && n != cnode && n != anode) { |
---|
| 2270 | st.push_back(n); |
---|
| 2271 | processed[n] = true; |
---|
| 2272 | Node m = bpred[n]; |
---|
| 2273 | while (m != INVALID && !processed[m]) { |
---|
| 2274 | st.push_back(m); |
---|
| 2275 | processed[m] = true; |
---|
| 2276 | m = bpred[m]; |
---|
| 2277 | } |
---|
| 2278 | while (!st.empty()) { |
---|
| 2279 | border.push_back(st.back()); |
---|
| 2280 | st.pop_back(); |
---|
| 2281 | } |
---|
| 2282 | } |
---|
| 2283 | } |
---|
| 2284 | } |
---|
| 2285 | |
---|
| 2286 | { |
---|
| 2287 | typename AuxUGraph::template NodeMap<bool> processed(ugraph, false); |
---|
| 2288 | std::vector<Node> st; |
---|
| 2289 | for (NodeIt n(ugraph); n != INVALID; ++n) { |
---|
| 2290 | if (!processed[n] && n != anode && n != bnode) { |
---|
| 2291 | st.push_back(n); |
---|
| 2292 | processed[n] = true; |
---|
| 2293 | Node m = cpred[n]; |
---|
| 2294 | while (m != INVALID && !processed[m]) { |
---|
| 2295 | st.push_back(m); |
---|
| 2296 | processed[m] = true; |
---|
| 2297 | m = cpred[m]; |
---|
| 2298 | } |
---|
| 2299 | while (!st.empty()) { |
---|
| 2300 | corder.push_back(st.back()); |
---|
| 2301 | st.pop_back(); |
---|
| 2302 | } |
---|
| 2303 | } |
---|
| 2304 | } |
---|
| 2305 | } |
---|
| 2306 | |
---|
| 2307 | typename AuxUGraph::template NodeMap<int> atree(ugraph, 0); |
---|
| 2308 | for (int i = aorder.size() - 1; i >= 0; --i) { |
---|
| 2309 | Node n = aorder[i]; |
---|
| 2310 | atree[n] = 1; |
---|
| 2311 | for (OutEdgeIt e(ugraph, n); e != INVALID; ++e) { |
---|
| 2312 | if (apred[ugraph.target(e)] == n) { |
---|
| 2313 | atree[n] += atree[ugraph.target(e)]; |
---|
| 2314 | } |
---|
| 2315 | } |
---|
| 2316 | } |
---|
| 2317 | |
---|
| 2318 | typename AuxUGraph::template NodeMap<int> btree(ugraph, 0); |
---|
| 2319 | for (int i = border.size() - 1; i >= 0; --i) { |
---|
| 2320 | Node n = border[i]; |
---|
| 2321 | btree[n] = 1; |
---|
| 2322 | for (OutEdgeIt e(ugraph, n); e != INVALID; ++e) { |
---|
| 2323 | if (bpred[ugraph.target(e)] == n) { |
---|
| 2324 | btree[n] += btree[ugraph.target(e)]; |
---|
| 2325 | } |
---|
| 2326 | } |
---|
| 2327 | } |
---|
| 2328 | |
---|
| 2329 | typename AuxUGraph::template NodeMap<int> apath(ugraph, 0); |
---|
| 2330 | apath[bnode] = apath[cnode] = 1; |
---|
| 2331 | typename AuxUGraph::template NodeMap<int> apath_btree(ugraph, 0); |
---|
| 2332 | apath_btree[bnode] = btree[bnode]; |
---|
| 2333 | for (int i = 1; i < int(aorder.size()); ++i) { |
---|
| 2334 | Node n = aorder[i]; |
---|
| 2335 | apath[n] = apath[apred[n]] + 1; |
---|
| 2336 | apath_btree[n] = btree[n] + apath_btree[apred[n]]; |
---|
| 2337 | } |
---|
| 2338 | |
---|
| 2339 | typename AuxUGraph::template NodeMap<int> bpath_atree(ugraph, 0); |
---|
| 2340 | bpath_atree[anode] = atree[anode]; |
---|
| 2341 | for (int i = 1; i < int(border.size()); ++i) { |
---|
| 2342 | Node n = border[i]; |
---|
| 2343 | bpath_atree[n] = atree[n] + bpath_atree[bpred[n]]; |
---|
| 2344 | } |
---|
| 2345 | |
---|
| 2346 | typename AuxUGraph::template NodeMap<int> cpath(ugraph, 0); |
---|
| 2347 | cpath[anode] = cpath[bnode] = 1; |
---|
| 2348 | typename AuxUGraph::template NodeMap<int> cpath_atree(ugraph, 0); |
---|
| 2349 | cpath_atree[anode] = atree[anode]; |
---|
| 2350 | typename AuxUGraph::template NodeMap<int> cpath_btree(ugraph, 0); |
---|
| 2351 | cpath_btree[bnode] = btree[bnode]; |
---|
| 2352 | for (int i = 1; i < int(corder.size()); ++i) { |
---|
| 2353 | Node n = corder[i]; |
---|
| 2354 | cpath[n] = cpath[cpred[n]] + 1; |
---|
| 2355 | cpath_atree[n] = atree[n] + cpath_atree[cpred[n]]; |
---|
| 2356 | cpath_btree[n] = btree[n] + cpath_btree[cpred[n]]; |
---|
| 2357 | } |
---|
| 2358 | |
---|
| 2359 | typename AuxUGraph::template NodeMap<int> third(ugraph); |
---|
| 2360 | for (NodeIt n(ugraph); n != INVALID; ++n) { |
---|
| 2361 | point_map[n].x = |
---|
| 2362 | bpath_atree[n] + cpath_atree[n] - atree[n] - cpath[n] + 1; |
---|
| 2363 | point_map[n].y = |
---|
| 2364 | cpath_btree[n] + apath_btree[n] - btree[n] - apath[n] + 1; |
---|
| 2365 | } |
---|
| 2366 | |
---|
| 2367 | } |
---|
| 2368 | |
---|
| 2369 | public: |
---|
| 2370 | |
---|
| 2371 | /// \brief Calculates the node locations |
---|
| 2372 | /// |
---|
| 2373 | /// This function calculates the node locations. |
---|
| 2374 | bool run() { |
---|
| 2375 | PlanarEmbedding<UGraph> pe(_ugraph); |
---|
| 2376 | if (!pe.run()) return false; |
---|
| 2377 | |
---|
| 2378 | run(pe); |
---|
| 2379 | return true; |
---|
| 2380 | } |
---|
| 2381 | |
---|
| 2382 | /// \brief Calculates the node locations according to a |
---|
| 2383 | /// combinatorical embedding |
---|
| 2384 | /// |
---|
| 2385 | /// This function calculates the node locations. The \c embedding |
---|
| 2386 | /// parameter should contain a valid combinatorical embedding, ie. |
---|
| 2387 | /// a valid cyclic order of the edges. |
---|
| 2388 | template <typename EmbeddingMap> |
---|
| 2389 | void run(const EmbeddingMap& embedding) { |
---|
| 2390 | typedef SmartUEdgeSet<UGraph> AuxUGraph; |
---|
| 2391 | |
---|
| 2392 | if (3 * countNodes(_ugraph) - 6 == countUEdges(_ugraph)) { |
---|
| 2393 | drawing(_ugraph, embedding, _point_map); |
---|
| 2394 | return; |
---|
| 2395 | } |
---|
| 2396 | |
---|
| 2397 | AuxUGraph aux_ugraph(_ugraph); |
---|
| 2398 | typename AuxUGraph::template EdgeMap<typename AuxUGraph::Edge> |
---|
| 2399 | aux_embedding(aux_ugraph); |
---|
| 2400 | |
---|
| 2401 | { |
---|
| 2402 | |
---|
| 2403 | typename UGraph::template UEdgeMap<typename AuxUGraph::UEdge> |
---|
| 2404 | ref(_ugraph); |
---|
| 2405 | |
---|
| 2406 | for (UEdgeIt e(_ugraph); e != INVALID; ++e) { |
---|
| 2407 | ref[e] = aux_ugraph.addEdge(_ugraph.source(e), _ugraph.target(e)); |
---|
| 2408 | } |
---|
| 2409 | |
---|
| 2410 | for (UEdgeIt e(_ugraph); e != INVALID; ++e) { |
---|
| 2411 | Edge ee = embedding[_ugraph.direct(e, true)]; |
---|
| 2412 | aux_embedding[aux_ugraph.direct(ref[e], true)] = |
---|
| 2413 | aux_ugraph.direct(ref[ee], _ugraph.direction(ee)); |
---|
| 2414 | ee = embedding[_ugraph.direct(e, false)]; |
---|
| 2415 | aux_embedding[aux_ugraph.direct(ref[e], false)] = |
---|
| 2416 | aux_ugraph.direct(ref[ee], _ugraph.direction(ee)); |
---|
| 2417 | } |
---|
| 2418 | } |
---|
| 2419 | _planarity_bits::makeConnected(aux_ugraph, aux_embedding); |
---|
| 2420 | _planarity_bits::makeBiNodeConnected(aux_ugraph, aux_embedding); |
---|
| 2421 | _planarity_bits::makeMaxPlanar(aux_ugraph, aux_embedding); |
---|
| 2422 | drawing(aux_ugraph, aux_embedding, _point_map); |
---|
| 2423 | } |
---|
| 2424 | |
---|
| 2425 | /// \brief The coordinate of the given node |
---|
| 2426 | /// |
---|
| 2427 | /// The coordinate of the given node. |
---|
| 2428 | Point operator[](const Node& node) { |
---|
| 2429 | return _point_map[node]; |
---|
| 2430 | } |
---|
| 2431 | |
---|
| 2432 | /// \brief Returns the grid embedding in a \e NodeMap. |
---|
| 2433 | /// |
---|
| 2434 | /// Returns the grid embedding in a \e NodeMap of \c dim2::Point<int> . |
---|
| 2435 | const PointMap& coords() const { |
---|
| 2436 | return _point_map; |
---|
| 2437 | } |
---|
| 2438 | |
---|
| 2439 | private: |
---|
| 2440 | |
---|
| 2441 | const UGraph& _ugraph; |
---|
| 2442 | PointMap _point_map; |
---|
| 2443 | |
---|
| 2444 | }; |
---|
| 2445 | |
---|
[2508] | 2446 | namespace _planarity_bits { |
---|
| 2447 | |
---|
| 2448 | template <typename ColorMap> |
---|
| 2449 | class KempeFilter { |
---|
| 2450 | public: |
---|
| 2451 | typedef typename ColorMap::Key Key; |
---|
| 2452 | typedef bool Value; |
---|
| 2453 | |
---|
| 2454 | KempeFilter(const ColorMap& color_map, |
---|
| 2455 | const typename ColorMap::Value& first, |
---|
| 2456 | const typename ColorMap::Value& second) |
---|
| 2457 | : _color_map(color_map), _first(first), _second(second) {} |
---|
| 2458 | |
---|
| 2459 | Value operator[](const Key& key) const { |
---|
| 2460 | return _color_map[key] == _first || _color_map[key] == _second; |
---|
| 2461 | } |
---|
| 2462 | |
---|
| 2463 | private: |
---|
| 2464 | const ColorMap& _color_map; |
---|
| 2465 | typename ColorMap::Value _first, _second; |
---|
| 2466 | }; |
---|
| 2467 | } |
---|
| 2468 | |
---|
| 2469 | /// \ingroup planar |
---|
| 2470 | /// |
---|
| 2471 | /// \brief Coloring planar graphs |
---|
| 2472 | /// |
---|
| 2473 | /// The graph coloring problem is the coloring of the graph nodes |
---|
| 2474 | /// such way that there are not adjacent nodes with the same |
---|
| 2475 | /// color. The planar graphs can be always colored with four colors, |
---|
| 2476 | /// it is proved by Appel and Haken and their proofs provide a |
---|
| 2477 | /// quadratic time algorithm for four coloring, but it could not be |
---|
| 2478 | /// used to implement efficient algorithm. The five and six coloring |
---|
| 2479 | /// can be made in linear time, but in this class the five coloring |
---|
| 2480 | /// has quadratic worst case time complexity. The two coloring (if |
---|
| 2481 | /// possible) is solvable with a graph search algorithm and it is |
---|
| 2482 | /// implemented in \ref bipartitePartitions() function in Lemon. To |
---|
| 2483 | /// decide whether the planar graph is three colorable is |
---|
| 2484 | /// NP-complete. |
---|
| 2485 | /// |
---|
| 2486 | /// This class contains member functions for calculate colorings |
---|
| 2487 | /// with five and six colors. The six coloring algorithm is a simple |
---|
| 2488 | /// greedy coloring on the backward minimum outgoing order of nodes. |
---|
| 2489 | /// This order can be computed such way, that in each phase the node |
---|
| 2490 | /// with least outgoing edges to unprocessed nodes is choosen. This |
---|
| 2491 | /// order guarantees that at the time of coloring of a node it has |
---|
| 2492 | /// at most five already colored adjacents. The five coloring |
---|
| 2493 | /// algorithm works in the same way, but if the greedy approach |
---|
| 2494 | /// fails to color with five color, ie. the node has five already |
---|
| 2495 | /// different colored neighbours, it swaps the colors in one |
---|
| 2496 | /// connected two colored set with the Kempe recoloring method. |
---|
| 2497 | template <typename UGraph> |
---|
| 2498 | class PlanarColoring { |
---|
| 2499 | public: |
---|
| 2500 | |
---|
| 2501 | UGRAPH_TYPEDEFS(typename UGraph); |
---|
| 2502 | |
---|
| 2503 | /// \brief The map type for store color indexes |
---|
| 2504 | typedef typename UGraph::template NodeMap<int> IndexMap; |
---|
| 2505 | /// \brief The map type for store colors |
---|
| 2506 | typedef ComposeMap<Palette, IndexMap> ColorMap; |
---|
| 2507 | |
---|
| 2508 | /// \brief Constructor |
---|
| 2509 | /// |
---|
| 2510 | /// Constructor |
---|
| 2511 | /// \pre The ugraph should be simple, ie. loop and parallel edge free. |
---|
| 2512 | PlanarColoring(const UGraph& ugraph) |
---|
| 2513 | : _ugraph(ugraph), _color_map(ugraph), _palette(0) { |
---|
| 2514 | _palette.add(Color(1,0,0)); |
---|
| 2515 | _palette.add(Color(0,1,0)); |
---|
| 2516 | _palette.add(Color(0,0,1)); |
---|
| 2517 | _palette.add(Color(1,1,0)); |
---|
| 2518 | _palette.add(Color(1,0,1)); |
---|
| 2519 | _palette.add(Color(0,1,1)); |
---|
| 2520 | } |
---|
| 2521 | |
---|
| 2522 | /// \brief Returns the \e NodeMap of color indexes |
---|
| 2523 | /// |
---|
| 2524 | /// Returns the \e NodeMap of color indexes. The values are in the |
---|
| 2525 | /// range \c [0..4] or \c [0..5] according to the five coloring or |
---|
| 2526 | /// six coloring. |
---|
| 2527 | IndexMap colorIndexMap() const { |
---|
| 2528 | return _color_map; |
---|
| 2529 | } |
---|
| 2530 | |
---|
| 2531 | /// \brief Returns the \e NodeMap of colors |
---|
| 2532 | /// |
---|
| 2533 | /// Returns the \e NodeMap of colors. The values are five or six |
---|
| 2534 | /// distinct \ref lemon::Color "colors". |
---|
| 2535 | ColorMap colorMap() const { |
---|
| 2536 | return composeMap(_palette, _color_map); |
---|
| 2537 | } |
---|
| 2538 | |
---|
| 2539 | /// \brief Returns the color index of the node |
---|
| 2540 | /// |
---|
| 2541 | /// Returns the color index of the node. The values are in the |
---|
| 2542 | /// range \c [0..4] or \c [0..5] according to the five coloring or |
---|
| 2543 | /// six coloring. |
---|
| 2544 | int colorIndex(const Node& node) const { |
---|
| 2545 | return _color_map[node]; |
---|
| 2546 | } |
---|
| 2547 | |
---|
| 2548 | /// \brief Returns the color of the node |
---|
| 2549 | /// |
---|
| 2550 | /// Returns the color of the node. The values are five or six |
---|
| 2551 | /// distinct \ref lemon::Color "colors". |
---|
| 2552 | int color(const Node& node) const { |
---|
| 2553 | return _palette[_color_map[node]]; |
---|
| 2554 | } |
---|
| 2555 | |
---|
| 2556 | |
---|
| 2557 | /// \brief Calculates a coloring with at most six colors |
---|
| 2558 | /// |
---|
| 2559 | /// This function calculates a coloring with at most six colors. The time |
---|
| 2560 | /// complexity of this variant is linear in the size of the graph. |
---|
| 2561 | /// \return %True when the algorithm could color the graph with six color. |
---|
| 2562 | /// If the algorithm fails, then the graph could not be planar. |
---|
| 2563 | bool runSixColoring() { |
---|
| 2564 | |
---|
| 2565 | typename UGraph::template NodeMap<int> heap_index(_ugraph, -1); |
---|
| 2566 | BucketHeap<typename UGraph::template NodeMap<int> > heap(heap_index); |
---|
| 2567 | |
---|
| 2568 | for (NodeIt n(_ugraph); n != INVALID; ++n) { |
---|
| 2569 | _color_map[n] = -2; |
---|
| 2570 | heap.push(n, countOutEdges(_ugraph, n)); |
---|
| 2571 | } |
---|
| 2572 | |
---|
| 2573 | std::vector<Node> order; |
---|
| 2574 | |
---|
| 2575 | while (!heap.empty()) { |
---|
| 2576 | Node n = heap.top(); |
---|
| 2577 | heap.pop(); |
---|
| 2578 | _color_map[n] = -1; |
---|
| 2579 | order.push_back(n); |
---|
| 2580 | for (OutEdgeIt e(_ugraph, n); e != INVALID; ++e) { |
---|
| 2581 | Node t = _ugraph.runningNode(e); |
---|
| 2582 | if (_color_map[t] == -2) { |
---|
| 2583 | heap.decrease(t, heap[t] - 1); |
---|
| 2584 | } |
---|
| 2585 | } |
---|
| 2586 | } |
---|
| 2587 | |
---|
| 2588 | for (int i = order.size() - 1; i >= 0; --i) { |
---|
| 2589 | std::vector<bool> forbidden(6, false); |
---|
| 2590 | for (OutEdgeIt e(_ugraph, order[i]); e != INVALID; ++e) { |
---|
| 2591 | Node t = _ugraph.runningNode(e); |
---|
| 2592 | if (_color_map[t] != -1) { |
---|
| 2593 | forbidden[_color_map[t]] = true; |
---|
| 2594 | } |
---|
| 2595 | } |
---|
| 2596 | for (int k = 0; k < 6; ++k) { |
---|
| 2597 | if (!forbidden[k]) { |
---|
| 2598 | _color_map[order[i]] = k; |
---|
| 2599 | break; |
---|
| 2600 | } |
---|
| 2601 | } |
---|
| 2602 | if (_color_map[order[i]] == -1) { |
---|
| 2603 | return false; |
---|
| 2604 | } |
---|
| 2605 | } |
---|
| 2606 | return true; |
---|
| 2607 | } |
---|
| 2608 | |
---|
| 2609 | private: |
---|
| 2610 | |
---|
| 2611 | bool recolor(const Node& u, const Node& v) { |
---|
| 2612 | int ucolor = _color_map[u]; |
---|
| 2613 | int vcolor = _color_map[v]; |
---|
| 2614 | typedef _planarity_bits::KempeFilter<IndexMap> KempeFilter; |
---|
| 2615 | KempeFilter filter(_color_map, ucolor, vcolor); |
---|
| 2616 | |
---|
| 2617 | typedef NodeSubUGraphAdaptor<const UGraph, const KempeFilter> KempeUGraph; |
---|
| 2618 | KempeUGraph kempe_ugraph(_ugraph, filter); |
---|
| 2619 | |
---|
| 2620 | std::vector<Node> comp; |
---|
| 2621 | Bfs<KempeUGraph> bfs(kempe_ugraph); |
---|
| 2622 | bfs.init(); |
---|
| 2623 | bfs.addSource(u); |
---|
| 2624 | while (!bfs.emptyQueue()) { |
---|
| 2625 | Node n = bfs.nextNode(); |
---|
| 2626 | if (n == v) return false; |
---|
| 2627 | comp.push_back(n); |
---|
| 2628 | bfs.processNextNode(); |
---|
| 2629 | } |
---|
| 2630 | |
---|
| 2631 | int scolor = ucolor + vcolor; |
---|
| 2632 | for (int i = 0; i < static_cast<int>(comp.size()); ++i) { |
---|
| 2633 | _color_map[comp[i]] = scolor - _color_map[comp[i]]; |
---|
| 2634 | } |
---|
| 2635 | |
---|
| 2636 | return true; |
---|
| 2637 | } |
---|
| 2638 | |
---|
| 2639 | template <typename EmbeddingMap> |
---|
| 2640 | void kempeRecoloring(const Node& node, const EmbeddingMap& embedding) { |
---|
| 2641 | std::vector<Node> nodes; |
---|
| 2642 | nodes.reserve(4); |
---|
| 2643 | |
---|
| 2644 | for (Edge e = OutEdgeIt(_ugraph, node); e != INVALID; e = embedding[e]) { |
---|
| 2645 | Node t = _ugraph.target(e); |
---|
| 2646 | if (_color_map[t] != -1) { |
---|
| 2647 | nodes.push_back(t); |
---|
| 2648 | if (nodes.size() == 4) break; |
---|
| 2649 | } |
---|
| 2650 | } |
---|
| 2651 | |
---|
| 2652 | int color = _color_map[nodes[0]]; |
---|
| 2653 | if (recolor(nodes[0], nodes[2])) { |
---|
| 2654 | _color_map[node] = color; |
---|
| 2655 | } else { |
---|
| 2656 | color = _color_map[nodes[1]]; |
---|
| 2657 | recolor(nodes[1], nodes[3]); |
---|
| 2658 | _color_map[node] = color; |
---|
| 2659 | } |
---|
| 2660 | } |
---|
| 2661 | |
---|
| 2662 | public: |
---|
| 2663 | |
---|
| 2664 | /// \brief Calculates a coloring with at most five colors |
---|
| 2665 | /// |
---|
| 2666 | /// This function calculates a coloring with at most five |
---|
| 2667 | /// colors. The wirst case time complexity of this variant is |
---|
| 2668 | /// quadratic in the size of the graph. |
---|
| 2669 | template <typename EmbeddingMap> |
---|
| 2670 | void runFiveColoring(const EmbeddingMap& embedding) { |
---|
| 2671 | |
---|
| 2672 | typename UGraph::template NodeMap<int> heap_index(_ugraph, -1); |
---|
| 2673 | BucketHeap<typename UGraph::template NodeMap<int> > heap(heap_index); |
---|
| 2674 | |
---|
| 2675 | for (NodeIt n(_ugraph); n != INVALID; ++n) { |
---|
| 2676 | _color_map[n] = -2; |
---|
| 2677 | heap.push(n, countOutEdges(_ugraph, n)); |
---|
| 2678 | } |
---|
| 2679 | |
---|
| 2680 | std::vector<Node> order; |
---|
| 2681 | |
---|
| 2682 | while (!heap.empty()) { |
---|
| 2683 | Node n = heap.top(); |
---|
| 2684 | heap.pop(); |
---|
| 2685 | _color_map[n] = -1; |
---|
| 2686 | order.push_back(n); |
---|
| 2687 | for (OutEdgeIt e(_ugraph, n); e != INVALID; ++e) { |
---|
| 2688 | Node t = _ugraph.runningNode(e); |
---|
| 2689 | if (_color_map[t] == -2) { |
---|
| 2690 | heap.decrease(t, heap[t] - 1); |
---|
| 2691 | } |
---|
| 2692 | } |
---|
| 2693 | } |
---|
| 2694 | |
---|
| 2695 | for (int i = order.size() - 1; i >= 0; --i) { |
---|
| 2696 | std::vector<bool> forbidden(5, false); |
---|
| 2697 | for (OutEdgeIt e(_ugraph, order[i]); e != INVALID; ++e) { |
---|
| 2698 | Node t = _ugraph.runningNode(e); |
---|
| 2699 | if (_color_map[t] != -1) { |
---|
| 2700 | forbidden[_color_map[t]] = true; |
---|
| 2701 | } |
---|
| 2702 | } |
---|
| 2703 | for (int k = 0; k < 5; ++k) { |
---|
| 2704 | if (!forbidden[k]) { |
---|
| 2705 | _color_map[order[i]] = k; |
---|
| 2706 | break; |
---|
| 2707 | } |
---|
| 2708 | } |
---|
| 2709 | if (_color_map[order[i]] == -1) { |
---|
| 2710 | kempeRecoloring(order[i], embedding); |
---|
| 2711 | } |
---|
| 2712 | } |
---|
| 2713 | } |
---|
| 2714 | |
---|
| 2715 | /// \brief Calculates a coloring with at most five colors |
---|
| 2716 | /// |
---|
| 2717 | /// This function calculates a coloring with at most five |
---|
| 2718 | /// colors. The worst case time complexity of this variant is |
---|
| 2719 | /// quadratic in the size of the graph, but it most cases it does |
---|
| 2720 | /// not have to use Kempe recoloring method, in this case it is |
---|
| 2721 | /// equivalent with the runSixColoring() algorithm. |
---|
| 2722 | /// \return %True when the graph is planar. |
---|
| 2723 | bool runFiveColoring() { |
---|
| 2724 | PlanarEmbedding<UGraph> pe(_ugraph); |
---|
| 2725 | if (!pe.run()) return false; |
---|
| 2726 | |
---|
| 2727 | runFiveColoring(pe.embeddingMap()); |
---|
| 2728 | return true; |
---|
| 2729 | } |
---|
| 2730 | |
---|
| 2731 | private: |
---|
| 2732 | |
---|
| 2733 | const UGraph& _ugraph; |
---|
| 2734 | IndexMap _color_map; |
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| 2735 | Palette _palette; |
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| 2736 | }; |
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| 2737 | |
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[2480] | 2738 | } |
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| 2739 | |
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| 2740 | #endif |
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