[906] | 1 | /* -*- C++ -*- |
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| 2 | * |
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[1956] | 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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[2391] | 5 | * Copyright (C) 2003-2007 |
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[1956] | 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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[1359] | 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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[906] | 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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[819] | 18 | |
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| 19 | ///\ingroup paths |
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| 20 | ///\file |
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| 21 | ///\brief Classes for representing paths in graphs. |
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[1151] | 22 | /// |
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[819] | 23 | |
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[921] | 24 | #ifndef LEMON_PATH_H |
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| 25 | #define LEMON_PATH_H |
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[819] | 26 | |
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| 27 | #include <vector> |
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| 28 | #include <algorithm> |
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| 29 | |
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[2335] | 30 | #include <lemon/path_utils.h> |
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[2247] | 31 | #include <lemon/error.h> |
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[1993] | 32 | #include <lemon/bits/invalid.h> |
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[819] | 33 | |
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[921] | 34 | namespace lemon { |
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[819] | 35 | |
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| 36 | /// \addtogroup paths |
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| 37 | /// @{ |
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| 38 | |
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| 39 | |
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[2335] | 40 | /// \brief A structure for representing directed paths in a graph. |
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| 41 | /// |
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| 42 | /// A structure for representing directed path in a graph. |
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| 43 | /// \param Graph The graph type in which the path is. |
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| 44 | /// |
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| 45 | /// In a sense, the path can be treated as a list of edges. The |
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| 46 | /// lemon path type stores just this list. As a consequence it |
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| 47 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 48 | /// cannot store the source. |
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| 49 | /// |
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| 50 | /// This implementation is a back and front insertable and erasable |
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| 51 | /// path type. It can be indexed in O(1) time. The front and back |
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| 52 | /// insertion and erasure is amortized O(1) time. The |
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| 53 | /// impelementation is based on two opposite organized vectors. |
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| 54 | template <typename _Graph> |
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[2247] | 55 | class Path { |
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[819] | 56 | public: |
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[2335] | 57 | |
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| 58 | typedef _Graph Graph; |
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[2247] | 59 | typedef typename Graph::Edge Edge; |
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| 60 | |
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[2335] | 61 | /// \brief Default constructor |
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| 62 | /// |
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| 63 | /// Default constructor |
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| 64 | Path() {} |
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[819] | 65 | |
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[2335] | 66 | /// \brief Template copy constructor |
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[2247] | 67 | /// |
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[2335] | 68 | /// This path can be initialized with any other path type. It just |
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| 69 | /// makes a copy of the given path. |
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| 70 | template <typename CPath> |
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| 71 | Path(const CPath& cpath) { |
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| 72 | copyPath(*this, cpath); |
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[819] | 73 | } |
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| 74 | |
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[2335] | 75 | /// \brief Template copy assignment |
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[819] | 76 | /// |
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[2335] | 77 | /// This path can be initialized with any other path type. It just |
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| 78 | /// makes a copy of the given path. |
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| 79 | template <typename CPath> |
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| 80 | Path& operator=(const CPath& cpath) { |
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| 81 | copyPath(*this, cpath); |
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| 82 | return *this; |
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[819] | 83 | } |
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| 84 | |
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[2335] | 85 | /// \brief Lemon style iterator for path edges |
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[2247] | 86 | /// |
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[2335] | 87 | /// This class is used to iterate on the edges of the paths. |
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| 88 | class EdgeIt { |
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[2247] | 89 | friend class Path; |
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| 90 | public: |
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[2335] | 91 | /// \brief Default constructor |
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| 92 | EdgeIt() {} |
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| 93 | /// \brief Invalid constructor |
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| 94 | EdgeIt(Invalid) : path(0), idx(-1) {} |
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| 95 | /// \brief Initializate the constructor to the first edge of path |
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| 96 | EdgeIt(const Path &_path) |
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| 97 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
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[819] | 98 | |
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[2335] | 99 | private: |
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[819] | 100 | |
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[2335] | 101 | EdgeIt(const Path &_path, int _idx) |
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| 102 | : idx(_idx), path(&_path) {} |
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[2247] | 103 | |
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[2335] | 104 | public: |
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| 105 | |
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| 106 | /// \brief Conversion to Edge |
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| 107 | operator const Edge&() const { |
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| 108 | return path->nth(idx); |
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[2247] | 109 | } |
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| 110 | |
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[2335] | 111 | /// \brief Next edge |
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| 112 | EdgeIt& operator++() { |
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| 113 | ++idx; |
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| 114 | if (idx >= path->length()) idx = -1; |
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[2247] | 115 | return *this; |
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| 116 | } |
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| 117 | |
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| 118 | /// \brief Comparison operator |
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[2335] | 119 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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[2247] | 120 | /// \brief Comparison operator |
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[2335] | 121 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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[2247] | 122 | /// \brief Comparison operator |
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[2335] | 123 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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[2247] | 124 | |
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| 125 | private: |
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| 126 | const Path *path; |
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[2335] | 127 | int idx; |
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[2247] | 128 | }; |
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| 129 | |
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[2335] | 130 | /// \brief Length of the path. |
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| 131 | int length() const { return head.size() + tail.size(); } |
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| 132 | /// \brief Returns whether the path is empty. |
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| 133 | bool empty() const { return head.empty() && tail.empty(); } |
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| 134 | |
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| 135 | /// \brief Resets the path to an empty path. |
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| 136 | void clear() { head.clear(); tail.clear(); } |
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| 137 | |
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| 138 | /// \brief Gives back the nth edge. |
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| 139 | /// |
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| 140 | /// \pre n is in the [0..length() - 1] range |
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| 141 | const Edge& nth(int n) const { |
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[2386] | 142 | return n < int(head.size()) ? *(head.rbegin() + n) : |
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[2335] | 143 | *(tail.begin() + (n - head.size())); |
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| 144 | } |
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| 145 | |
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| 146 | /// \brief Initializes edge iterator to point to the nth edge |
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| 147 | /// |
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| 148 | /// \pre n is in the [0..length() - 1] range |
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| 149 | EdgeIt nthIt(int n) const { |
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| 150 | return EdgeIt(*this, n); |
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| 151 | } |
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| 152 | |
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| 153 | /// \brief Gives back the first edge of the path |
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| 154 | const Edge& front() const { |
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| 155 | return head.empty() ? tail.front() : head.back(); |
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| 156 | } |
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| 157 | |
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| 158 | /// \brief Add a new edge before the current path |
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| 159 | void addFront(const Edge& edge) { |
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| 160 | head.push_back(edge); |
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| 161 | } |
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| 162 | |
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| 163 | /// \brief Erase the first edge of the path |
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| 164 | void eraseFront() { |
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| 165 | if (!head.empty()) { |
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| 166 | head.pop_back(); |
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| 167 | } else { |
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| 168 | head.clear(); |
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| 169 | int halfsize = tail.size() / 2; |
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| 170 | head.resize(halfsize); |
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| 171 | std::copy(tail.begin() + 1, tail.begin() + halfsize + 1, |
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| 172 | head.rbegin()); |
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| 173 | std::copy(tail.begin() + halfsize + 1, tail.end(), tail.begin()); |
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| 174 | tail.resize(tail.size() - halfsize - 1); |
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| 175 | } |
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| 176 | } |
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| 177 | |
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| 178 | /// \brief Gives back the last edge of the path |
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| 179 | const Edge& back() const { |
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| 180 | return tail.empty() ? head.front() : tail.back(); |
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| 181 | } |
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| 182 | |
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| 183 | /// \brief Add a new edge behind the current path |
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| 184 | void addBack(const Edge& edge) { |
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| 185 | tail.push_back(edge); |
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| 186 | } |
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| 187 | |
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| 188 | /// \brief Erase the last edge of the path |
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| 189 | void eraseBack() { |
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| 190 | if (!tail.empty()) { |
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| 191 | tail.pop_back(); |
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| 192 | } else { |
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| 193 | int halfsize = head.size() / 2; |
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| 194 | tail.resize(halfsize); |
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| 195 | std::copy(head.begin() + 1, head.begin() + halfsize + 1, |
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| 196 | tail.rbegin()); |
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| 197 | std::copy(head.begin() + halfsize + 1, head.end(), head.begin()); |
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| 198 | head.resize(head.size() - halfsize - 1); |
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| 199 | } |
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| 200 | } |
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| 201 | |
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| 202 | |
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| 203 | |
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| 204 | typedef True BuildTag; |
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| 205 | |
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| 206 | template <typename CPath> |
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| 207 | void build(const CPath& path) { |
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| 208 | int len = path.length(); |
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| 209 | tail.reserve(len); |
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| 210 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
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| 211 | tail.push_back(it); |
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| 212 | } |
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| 213 | } |
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| 214 | |
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| 215 | template <typename CPath> |
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| 216 | void buildRev(const CPath& path) { |
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| 217 | int len = path.length(); |
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| 218 | head.reserve(len); |
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[2357] | 219 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
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[2335] | 220 | head.push_back(it); |
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| 221 | } |
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| 222 | } |
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| 223 | |
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| 224 | protected: |
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| 225 | typedef std::vector<Edge> Container; |
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| 226 | Container head, tail; |
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| 227 | |
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| 228 | }; |
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| 229 | |
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| 230 | /// \brief A structure for representing directed paths in a graph. |
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| 231 | /// |
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| 232 | /// A structure for representing directed path in a graph. |
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| 233 | /// \param Graph The graph type in which the path is. |
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| 234 | /// |
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| 235 | /// In a sense, the path can be treated as a list of edges. The |
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| 236 | /// lemon path type stores just this list. As a consequence it |
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| 237 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 238 | /// cannot store the source. |
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| 239 | /// |
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| 240 | /// This implementation is a just back insertable and erasable path |
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| 241 | /// type. It can be indexed in O(1) time. The back insertion and |
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| 242 | /// erasure is amortized O(1) time. This implementation is faster |
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| 243 | /// then the \c Path type because it use just one vector for the |
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| 244 | /// edges. |
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| 245 | template <typename _Graph> |
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| 246 | class SimplePath { |
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| 247 | public: |
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| 248 | |
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| 249 | typedef _Graph Graph; |
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| 250 | typedef typename Graph::Edge Edge; |
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| 251 | |
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| 252 | /// \brief Default constructor |
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| 253 | /// |
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| 254 | /// Default constructor |
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| 255 | SimplePath() {} |
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| 256 | |
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| 257 | /// \brief Template copy constructor |
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| 258 | /// |
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| 259 | /// This path can be initialized with any other path type. It just |
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| 260 | /// makes a copy of the given path. |
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| 261 | template <typename CPath> |
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| 262 | SimplePath(const CPath& cpath) { |
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| 263 | copyPath(*this, cpath); |
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| 264 | } |
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| 265 | |
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| 266 | /// \brief Template copy assignment |
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| 267 | /// |
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| 268 | /// This path can be initialized with any other path type. It just |
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| 269 | /// makes a copy of the given path. |
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| 270 | template <typename CPath> |
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| 271 | SimplePath& operator=(const CPath& cpath) { |
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| 272 | copyPath(*this, cpath); |
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| 273 | return *this; |
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| 274 | } |
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| 275 | |
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[2247] | 276 | /// \brief Iterator class to iterate on the edges of the paths |
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| 277 | /// |
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| 278 | /// This class is used to iterate on the edges of the paths |
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[2335] | 279 | /// |
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[2247] | 280 | /// Of course it converts to Graph::Edge |
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[819] | 281 | class EdgeIt { |
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[2335] | 282 | friend class SimplePath; |
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| 283 | public: |
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| 284 | /// Default constructor |
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| 285 | EdgeIt() {} |
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| 286 | /// Invalid constructor |
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| 287 | EdgeIt(Invalid) : path(0), idx(-1) {} |
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| 288 | /// \brief Initializate the constructor to the first edge of path |
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| 289 | EdgeIt(const SimplePath &_path) |
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| 290 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
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| 291 | |
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| 292 | private: |
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| 293 | |
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| 294 | /// Constructor with starting point |
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| 295 | EdgeIt(const SimplePath &_path, int _idx) |
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| 296 | : idx(_idx), path(&_path) {} |
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| 297 | |
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[2247] | 298 | public: |
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[819] | 299 | |
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[2335] | 300 | ///Conversion to Graph::Edge |
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| 301 | operator const Edge&() const { |
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| 302 | return path->nth(idx); |
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[819] | 303 | } |
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| 304 | |
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[2335] | 305 | /// Next edge |
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[2247] | 306 | EdgeIt& operator++() { |
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[2335] | 307 | ++idx; |
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| 308 | if (idx >= path->length()) idx = -1; |
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[2247] | 309 | return *this; |
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| 310 | } |
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| 311 | |
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[819] | 312 | /// Comparison operator |
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[2335] | 313 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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| 314 | /// Comparison operator |
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| 315 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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| 316 | /// Comparison operator |
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| 317 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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[2247] | 318 | |
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[2335] | 319 | private: |
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| 320 | const SimplePath *path; |
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| 321 | int idx; |
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| 322 | }; |
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| 323 | |
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| 324 | /// \brief Length of the path. |
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| 325 | int length() const { return data.size(); } |
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| 326 | /// \brief Returns whether the path is empty. |
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| 327 | bool empty() const { return data.empty(); } |
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| 328 | |
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| 329 | /// \brief Resets the path to an empty path. |
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| 330 | void clear() { data.clear(); } |
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| 331 | |
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| 332 | /// \brief Gives back the nth edge. |
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| 333 | /// |
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| 334 | /// \pre n is in the [0..length() - 1] range |
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| 335 | const Edge& nth(int n) const { |
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| 336 | return data[n]; |
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| 337 | } |
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| 338 | |
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| 339 | /// \brief Initializes edge iterator to point to the nth edge. |
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| 340 | EdgeIt nthIt(int n) const { |
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| 341 | return EdgeIt(*this, n); |
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| 342 | } |
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| 343 | |
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[2419] | 344 | /// \brief Gives back the first edge of the path. |
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| 345 | const Edge& front() const { |
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| 346 | return data.front(); |
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| 347 | } |
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| 348 | |
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[2335] | 349 | /// \brief Gives back the last edge of the path. |
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| 350 | const Edge& back() const { |
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| 351 | return data.back(); |
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| 352 | } |
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| 353 | |
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| 354 | /// \brief Add a new edge behind the current path. |
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| 355 | void addBack(const Edge& edge) { |
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| 356 | data.push_back(edge); |
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| 357 | } |
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| 358 | |
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| 359 | /// \brief Erase the last edge of the path |
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| 360 | void eraseBack() { |
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| 361 | data.pop_back(); |
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| 362 | } |
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| 363 | |
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| 364 | typedef True BuildTag; |
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| 365 | |
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| 366 | template <typename CPath> |
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| 367 | void build(const CPath& path) { |
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| 368 | int len = path.length(); |
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| 369 | data.resize(len); |
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| 370 | int index = 0; |
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| 371 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
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| 372 | data[index] = it;; |
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| 373 | ++index; |
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| 374 | } |
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| 375 | } |
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| 376 | |
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| 377 | template <typename CPath> |
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| 378 | void buildRev(const CPath& path) { |
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| 379 | int len = path.length(); |
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| 380 | data.resize(len); |
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| 381 | int index = len; |
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[2357] | 382 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
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[2335] | 383 | --index; |
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| 384 | data[index] = it;; |
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| 385 | } |
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| 386 | } |
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| 387 | |
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| 388 | protected: |
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| 389 | typedef std::vector<Edge> Container; |
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| 390 | Container data; |
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| 391 | |
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| 392 | }; |
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| 393 | |
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| 394 | /// \brief A structure for representing directed paths in a graph. |
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| 395 | /// |
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| 396 | /// A structure for representing directed path in a graph. |
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| 397 | /// \param Graph The graph type in which the path is. |
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| 398 | /// |
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| 399 | /// In a sense, the path can be treated as a list of edges. The |
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| 400 | /// lemon path type stores just this list. As a consequence it |
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| 401 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 402 | /// cannot store the source. |
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| 403 | /// |
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| 404 | /// This implementation is a back and front insertable and erasable |
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| 405 | /// path type. It can be indexed in O(k) time, where k is the rank |
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| 406 | /// of the edge in the path. The length can be computed in O(n) |
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| 407 | /// time. The front and back insertion and erasure is O(1) time |
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| 408 | /// and it can be splited and spliced in O(1) time. |
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| 409 | template <typename _Graph> |
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| 410 | class ListPath { |
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| 411 | public: |
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| 412 | |
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| 413 | typedef _Graph Graph; |
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| 414 | typedef typename Graph::Edge Edge; |
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| 415 | |
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| 416 | protected: |
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| 417 | |
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| 418 | // the std::list<> is incompatible |
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| 419 | // hard to create invalid iterator |
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| 420 | struct Node { |
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| 421 | Edge edge; |
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| 422 | Node *next, *prev; |
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| 423 | }; |
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| 424 | |
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| 425 | Node *first, *last; |
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| 426 | |
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| 427 | std::allocator<Node> alloc; |
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| 428 | |
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| 429 | public: |
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| 430 | |
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| 431 | /// \brief Default constructor |
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| 432 | /// |
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| 433 | /// Default constructor |
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| 434 | ListPath() : first(0), last(0) {} |
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| 435 | |
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| 436 | /// \brief Template copy constructor |
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| 437 | /// |
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| 438 | /// This path can be initialized with any other path type. It just |
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| 439 | /// makes a copy of the given path. |
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| 440 | template <typename CPath> |
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| 441 | ListPath(const CPath& cpath) : first(0), last(0) { |
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| 442 | copyPath(*this, cpath); |
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| 443 | } |
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| 444 | |
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| 445 | /// \brief Destructor of the path |
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| 446 | /// |
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| 447 | /// Destructor of the path |
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| 448 | ~ListPath() { |
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| 449 | clear(); |
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| 450 | } |
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| 451 | |
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| 452 | /// \brief Template copy assignment |
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| 453 | /// |
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| 454 | /// This path can be initialized with any other path type. It just |
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| 455 | /// makes a copy of the given path. |
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| 456 | template <typename CPath> |
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| 457 | ListPath& operator=(const CPath& cpath) { |
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| 458 | copyPath(*this, cpath); |
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| 459 | return *this; |
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| 460 | } |
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| 461 | |
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| 462 | /// \brief Iterator class to iterate on the edges of the paths |
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| 463 | /// |
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| 464 | /// This class is used to iterate on the edges of the paths |
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| 465 | /// |
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| 466 | /// Of course it converts to Graph::Edge |
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| 467 | class EdgeIt { |
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| 468 | friend class ListPath; |
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| 469 | public: |
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| 470 | /// Default constructor |
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| 471 | EdgeIt() {} |
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| 472 | /// Invalid constructor |
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| 473 | EdgeIt(Invalid) : path(0), node(0) {} |
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| 474 | /// \brief Initializate the constructor to the first edge of path |
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| 475 | EdgeIt(const ListPath &_path) |
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| 476 | : path(&_path), node(_path.first) {} |
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| 477 | |
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| 478 | protected: |
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| 479 | |
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| 480 | EdgeIt(const ListPath &_path, Node *_node) |
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| 481 | : path(&_path), node(_node) {} |
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| 482 | |
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| 483 | |
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| 484 | public: |
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| 485 | |
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| 486 | ///Conversion to Graph::Edge |
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| 487 | operator const Edge&() const { |
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| 488 | return node->edge; |
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| 489 | } |
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| 490 | |
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| 491 | /// Next edge |
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| 492 | EdgeIt& operator++() { |
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| 493 | node = node->next; |
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| 494 | return *this; |
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| 495 | } |
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| 496 | |
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[819] | 497 | /// Comparison operator |
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[2335] | 498 | bool operator==(const EdgeIt& e) const { return node==e.node; } |
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| 499 | /// Comparison operator |
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| 500 | bool operator!=(const EdgeIt& e) const { return node!=e.node; } |
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| 501 | /// Comparison operator |
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| 502 | bool operator<(const EdgeIt& e) const { return node<e.node; } |
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[2247] | 503 | |
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[2335] | 504 | private: |
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| 505 | const ListPath *path; |
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| 506 | Node *node; |
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| 507 | }; |
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| 508 | |
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| 509 | /// \brief Gives back the nth edge. |
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| 510 | /// |
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| 511 | /// Gives back the nth edge in O(n) time. |
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| 512 | /// \pre n is in the [0..length() - 1] range |
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| 513 | const Edge& nth(int n) const { |
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| 514 | Node *node = first; |
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| 515 | for (int i = 0; i < n; ++i) { |
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| 516 | node = node->next; |
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| 517 | } |
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| 518 | return node->edge; |
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| 519 | } |
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| 520 | |
---|
| 521 | /// \brief Initializes edge iterator to point to the nth edge. |
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| 522 | EdgeIt nthIt(int n) const { |
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| 523 | Node *node = first; |
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| 524 | for (int i = 0; i < n; ++i) { |
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| 525 | node = node->next; |
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| 526 | } |
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| 527 | return EdgeIt(*this, node); |
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| 528 | } |
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| 529 | |
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| 530 | /// \brief Length of the path. |
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| 531 | int length() const { |
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| 532 | int len = 0; |
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| 533 | Node *node = first; |
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| 534 | while (node != 0) { |
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| 535 | node = node->next; |
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| 536 | ++len; |
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| 537 | } |
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| 538 | return len; |
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| 539 | } |
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| 540 | |
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| 541 | /// \brief Returns whether the path is empty. |
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| 542 | bool empty() const { return first == 0; } |
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| 543 | |
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| 544 | /// \brief Resets the path to an empty path. |
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| 545 | void clear() { |
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| 546 | while (first != 0) { |
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| 547 | last = first->next; |
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| 548 | alloc.destroy(first); |
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| 549 | alloc.deallocate(first, 1); |
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| 550 | first = last; |
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| 551 | } |
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| 552 | } |
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| 553 | |
---|
| 554 | /// \brief Gives back the first edge of the path |
---|
| 555 | const Edge& front() const { |
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| 556 | return first->edge; |
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| 557 | } |
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| 558 | |
---|
| 559 | /// \brief Add a new edge before the current path |
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| 560 | void addFront(const Edge& edge) { |
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| 561 | Node *node = alloc.allocate(1); |
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| 562 | alloc.construct(node, Node()); |
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| 563 | node->prev = 0; |
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| 564 | node->next = first; |
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| 565 | node->edge = edge; |
---|
| 566 | if (first) { |
---|
| 567 | first->prev = node; |
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| 568 | first = node; |
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| 569 | } else { |
---|
| 570 | first = last = node; |
---|
| 571 | } |
---|
| 572 | } |
---|
| 573 | |
---|
| 574 | /// \brief Erase the first edge of the path |
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| 575 | void eraseFront() { |
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| 576 | Node *node = first; |
---|
| 577 | first = first->next; |
---|
| 578 | if (first) { |
---|
| 579 | first->prev = 0; |
---|
| 580 | } else { |
---|
| 581 | last = 0; |
---|
| 582 | } |
---|
| 583 | alloc.destroy(node); |
---|
| 584 | alloc.deallocate(node, 1); |
---|
| 585 | } |
---|
| 586 | |
---|
| 587 | /// \brief Gives back the last edge of the path. |
---|
| 588 | const Edge& back() const { |
---|
| 589 | return last->edge; |
---|
| 590 | } |
---|
| 591 | |
---|
| 592 | /// \brief Add a new edge behind the current path. |
---|
| 593 | void addBack(const Edge& edge) { |
---|
| 594 | Node *node = alloc.allocate(1); |
---|
| 595 | alloc.construct(node, Node()); |
---|
| 596 | node->next = 0; |
---|
| 597 | node->prev = last; |
---|
| 598 | node->edge = edge; |
---|
| 599 | if (last) { |
---|
| 600 | last->next = node; |
---|
| 601 | last = node; |
---|
| 602 | } else { |
---|
| 603 | last = first = node; |
---|
| 604 | } |
---|
| 605 | } |
---|
| 606 | |
---|
| 607 | /// \brief Erase the last edge of the path |
---|
| 608 | void eraseBack() { |
---|
| 609 | Node *node = last; |
---|
| 610 | last = last->prev; |
---|
| 611 | if (last) { |
---|
| 612 | last->next = 0; |
---|
| 613 | } else { |
---|
| 614 | first = 0; |
---|
| 615 | } |
---|
| 616 | alloc.destroy(node); |
---|
| 617 | alloc.deallocate(node, 1); |
---|
| 618 | } |
---|
| 619 | |
---|
| 620 | /// \brief Splicing the given path to the current path. |
---|
| 621 | /// |
---|
| 622 | /// It splices the \c tpath to the back of the current path and \c |
---|
| 623 | /// tpath becomes empty. The time complexity of this function is |
---|
| 624 | /// O(1). |
---|
| 625 | void spliceBack(ListPath& tpath) { |
---|
| 626 | if (first) { |
---|
| 627 | if (tpath.first) { |
---|
| 628 | last->next = tpath.first; |
---|
| 629 | tpath.first->prev = last; |
---|
| 630 | last = tpath.last; |
---|
| 631 | } |
---|
| 632 | } else { |
---|
| 633 | first = tpath.first; |
---|
| 634 | last = tpath.last; |
---|
| 635 | } |
---|
| 636 | tpath.first = tpath.last = 0; |
---|
| 637 | } |
---|
| 638 | |
---|
| 639 | /// \brief Splicing the given path to the current path. |
---|
| 640 | /// |
---|
| 641 | /// It splices the \c tpath before the current path and \c tpath |
---|
| 642 | /// becomes empty. The time complexity of this function |
---|
| 643 | /// is O(1). |
---|
| 644 | void spliceFront(ListPath& tpath) { |
---|
| 645 | if (first) { |
---|
| 646 | if (tpath.first) { |
---|
| 647 | first->prev = tpath.last; |
---|
| 648 | tpath.last->next = first; |
---|
| 649 | first = tpath.first; |
---|
| 650 | } |
---|
| 651 | } else { |
---|
| 652 | first = tpath.first; |
---|
| 653 | last = tpath.last; |
---|
| 654 | } |
---|
| 655 | tpath.first = tpath.last = 0; |
---|
| 656 | } |
---|
| 657 | |
---|
| 658 | /// \brief Splicing the given path into the current path. |
---|
| 659 | /// |
---|
| 660 | /// It splices the \c tpath into the current path before the |
---|
| 661 | /// position of \c it iterator and \c tpath becomes empty. The |
---|
| 662 | /// time complexity of this function is O(1). If the \c it is \c |
---|
| 663 | /// INVALID then it will splice behind the current path. |
---|
| 664 | void splice(EdgeIt it, ListPath& tpath) { |
---|
| 665 | if (it.node) { |
---|
| 666 | if (tpath.first) { |
---|
| 667 | tpath.first->prev = it.node->prev; |
---|
| 668 | if (it.node->prev) { |
---|
| 669 | it.node->prev->next = tpath.first; |
---|
| 670 | } else { |
---|
| 671 | first = tpath.first; |
---|
| 672 | } |
---|
| 673 | it.node->prev = tpath.last; |
---|
| 674 | tpath.last->next = it.node; |
---|
| 675 | } |
---|
| 676 | } else { |
---|
| 677 | if (first) { |
---|
| 678 | if (tpath.first) { |
---|
| 679 | last->next = tpath.first; |
---|
| 680 | tpath.first->prev = last; |
---|
| 681 | last = tpath.last; |
---|
| 682 | } |
---|
| 683 | } else { |
---|
| 684 | first = tpath.first; |
---|
| 685 | last = tpath.last; |
---|
| 686 | } |
---|
| 687 | } |
---|
| 688 | tpath.first = tpath.last = 0; |
---|
| 689 | } |
---|
| 690 | |
---|
| 691 | /// \brief Spliting the current path. |
---|
| 692 | /// |
---|
| 693 | /// It splits the current path into two parts. The part before \c |
---|
| 694 | /// it iterator will remain in the current path and the part from |
---|
| 695 | /// the it will put into the \c tpath. If the \c tpath had edges |
---|
| 696 | /// before the operation they will be removed first. The time |
---|
| 697 | /// complexity of this function is O(1) plus the clearing of \c |
---|
| 698 | /// tpath. If the \c it is \c INVALID then it just clears \c |
---|
| 699 | /// tpath. |
---|
| 700 | void split(EdgeIt it, ListPath& tpath) { |
---|
| 701 | tpath.clear(); |
---|
| 702 | if (it.node) { |
---|
| 703 | tpath.first = it.node; |
---|
| 704 | tpath.last = last; |
---|
| 705 | if (it.node->prev) { |
---|
| 706 | last = it.node->prev; |
---|
| 707 | last->next = 0; |
---|
| 708 | } else { |
---|
| 709 | first = last = 0; |
---|
| 710 | } |
---|
| 711 | it.node->prev = 0; |
---|
| 712 | } |
---|
| 713 | } |
---|
| 714 | |
---|
| 715 | |
---|
| 716 | typedef True BuildTag; |
---|
| 717 | |
---|
| 718 | template <typename CPath> |
---|
| 719 | void build(const CPath& path) { |
---|
| 720 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
---|
| 721 | addBack(it); |
---|
| 722 | } |
---|
| 723 | } |
---|
| 724 | |
---|
| 725 | template <typename CPath> |
---|
| 726 | void buildRev(const CPath& path) { |
---|
[2357] | 727 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
---|
[2335] | 728 | addFront(it); |
---|
| 729 | } |
---|
| 730 | } |
---|
| 731 | |
---|
| 732 | }; |
---|
| 733 | |
---|
| 734 | /// \brief A structure for representing directed paths in a graph. |
---|
| 735 | /// |
---|
| 736 | /// A structure for representing directed path in a graph. |
---|
| 737 | /// \param Graph The graph type in which the path is. |
---|
| 738 | /// |
---|
| 739 | /// In a sense, the path can be treated as a list of edges. The |
---|
| 740 | /// lemon path type stores just this list. As a consequence it |
---|
| 741 | /// cannot enumerate the nodes in the path and the zero length paths |
---|
| 742 | /// cannot store the source. |
---|
| 743 | /// |
---|
| 744 | /// This implementation is completly static, so it cannot be |
---|
| 745 | /// modified exclude the assign an other path. It is intented to be |
---|
[2336] | 746 | /// used when you want to store a large number of paths because it is |
---|
[2335] | 747 | /// the most memory efficient path type in the lemon. |
---|
| 748 | template <typename _Graph> |
---|
| 749 | class StaticPath { |
---|
| 750 | public: |
---|
| 751 | |
---|
| 752 | typedef _Graph Graph; |
---|
| 753 | typedef typename Graph::Edge Edge; |
---|
| 754 | |
---|
| 755 | /// \brief Default constructor |
---|
| 756 | /// |
---|
| 757 | /// Default constructor |
---|
| 758 | StaticPath() : len(0), edges(0) {} |
---|
| 759 | |
---|
| 760 | /// \brief Template copy constructor |
---|
| 761 | /// |
---|
| 762 | /// This path can be initialized with any other path type. It just |
---|
| 763 | /// makes a copy of the given path. |
---|
| 764 | template <typename CPath> |
---|
| 765 | StaticPath(const CPath& cpath) : edges(0) { |
---|
| 766 | copyPath(*this, cpath); |
---|
| 767 | } |
---|
| 768 | |
---|
| 769 | /// \brief Destructor of the path |
---|
| 770 | /// |
---|
| 771 | /// Destructor of the path |
---|
| 772 | ~StaticPath() { |
---|
| 773 | if (edges) delete[] edges; |
---|
| 774 | } |
---|
| 775 | |
---|
| 776 | /// \brief Template copy assignment |
---|
| 777 | /// |
---|
| 778 | /// This path can be initialized with any other path type. It just |
---|
| 779 | /// makes a copy of the given path. |
---|
| 780 | template <typename CPath> |
---|
| 781 | StaticPath& operator=(const CPath& cpath) { |
---|
| 782 | copyPath(*this, cpath); |
---|
| 783 | return *this; |
---|
| 784 | } |
---|
| 785 | |
---|
| 786 | /// \brief Iterator class to iterate on the edges of the paths |
---|
| 787 | /// |
---|
| 788 | /// This class is used to iterate on the edges of the paths |
---|
| 789 | /// |
---|
| 790 | /// Of course it converts to Graph::Edge |
---|
| 791 | class EdgeIt { |
---|
| 792 | friend class StaticPath; |
---|
| 793 | public: |
---|
| 794 | /// Default constructor |
---|
| 795 | EdgeIt() {} |
---|
| 796 | /// Invalid constructor |
---|
| 797 | EdgeIt(Invalid) : path(0), idx(-1) {} |
---|
| 798 | /// Initializate the constructor to the first edge of path |
---|
| 799 | EdgeIt(const StaticPath &_path) |
---|
| 800 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
---|
[819] | 801 | |
---|
| 802 | private: |
---|
[2247] | 803 | |
---|
[2335] | 804 | /// Constructor with starting point |
---|
| 805 | EdgeIt(const StaticPath &_path, int _idx) |
---|
| 806 | : idx(_idx), path(&_path) {} |
---|
| 807 | |
---|
| 808 | public: |
---|
| 809 | |
---|
| 810 | ///Conversion to Graph::Edge |
---|
| 811 | operator const Edge&() const { |
---|
| 812 | return path->nth(idx); |
---|
| 813 | } |
---|
| 814 | |
---|
| 815 | /// Next edge |
---|
| 816 | EdgeIt& operator++() { |
---|
| 817 | ++idx; |
---|
| 818 | if (idx >= path->length()) idx = -1; |
---|
| 819 | return *this; |
---|
| 820 | } |
---|
| 821 | |
---|
| 822 | /// Comparison operator |
---|
| 823 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
---|
| 824 | /// Comparison operator |
---|
| 825 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
---|
| 826 | /// Comparison operator |
---|
| 827 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
---|
| 828 | |
---|
| 829 | private: |
---|
| 830 | const StaticPath *path; |
---|
| 831 | int idx; |
---|
[819] | 832 | }; |
---|
| 833 | |
---|
[2335] | 834 | /// \brief Gives back the nth edge. |
---|
| 835 | /// |
---|
| 836 | /// \pre n is in the [0..length() - 1] range |
---|
| 837 | const Edge& nth(int n) const { |
---|
| 838 | return edges[n]; |
---|
| 839 | } |
---|
[819] | 840 | |
---|
[2335] | 841 | /// \brief Initializes edge iterator to point to the nth edge. |
---|
| 842 | EdgeIt nthIt(int n) const { |
---|
| 843 | return EdgeIt(*this, n); |
---|
| 844 | } |
---|
[819] | 845 | |
---|
[2335] | 846 | /// \brief Gives back the length of the path. |
---|
| 847 | int length() const { return len; } |
---|
[819] | 848 | |
---|
[2335] | 849 | /// \brief Returns true when the path is empty. |
---|
| 850 | int empty() const { return len == 0; } |
---|
[819] | 851 | |
---|
[2335] | 852 | /// \break Erase all edge in the graph. |
---|
| 853 | void clear() { |
---|
| 854 | len = 0; |
---|
| 855 | if (edges) delete[] edges; |
---|
| 856 | edges = 0; |
---|
| 857 | } |
---|
[819] | 858 | |
---|
[2335] | 859 | /// \brief Gives back the first edge of the path. |
---|
| 860 | const Edge& front() const { |
---|
| 861 | return edges[0]; |
---|
| 862 | } |
---|
[819] | 863 | |
---|
[2335] | 864 | /// \brief Gives back the last edge of the path. |
---|
| 865 | const Edge& back() const { |
---|
| 866 | return edges[len - 1]; |
---|
| 867 | } |
---|
| 868 | |
---|
| 869 | |
---|
| 870 | typedef True BuildTag; |
---|
| 871 | |
---|
| 872 | template <typename CPath> |
---|
| 873 | void build(const CPath& path) { |
---|
| 874 | len = path.length(); |
---|
| 875 | edges = new Edge[len]; |
---|
| 876 | int index = 0; |
---|
| 877 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
---|
| 878 | edges[index] = it; |
---|
| 879 | ++index; |
---|
[2247] | 880 | } |
---|
[2335] | 881 | } |
---|
[819] | 882 | |
---|
[2335] | 883 | template <typename CPath> |
---|
| 884 | void buildRev(const CPath& path) { |
---|
| 885 | len = path.length(); |
---|
| 886 | edges = new Edge[len]; |
---|
| 887 | int index = len; |
---|
[2357] | 888 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
---|
[2335] | 889 | --index; |
---|
| 890 | edges[index] = it; |
---|
[2247] | 891 | } |
---|
[2335] | 892 | } |
---|
[837] | 893 | |
---|
[2335] | 894 | private: |
---|
| 895 | int len; |
---|
| 896 | Edge* edges; |
---|
[819] | 897 | }; |
---|
| 898 | |
---|
| 899 | ///@} |
---|
| 900 | |
---|
[921] | 901 | } // namespace lemon |
---|
[819] | 902 | |
---|
[921] | 903 | #endif // LEMON_PATH_H |
---|