[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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| 5 | * Copyright (C) 2003-2006 |
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| 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 | |
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| 20 | ///\ingroup paths |
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| 21 | ///\file |
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| 22 | ///\brief Classes for representing paths in graphs. |
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[1151] | 23 | /// |
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[819] | 24 | |
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[921] | 25 | #ifndef LEMON_PATH_H |
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| 26 | #define LEMON_PATH_H |
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[819] | 27 | |
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| 28 | #include <vector> |
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| 29 | #include <algorithm> |
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| 30 | |
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[2335] | 31 | #include <lemon/path_utils.h> |
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[2247] | 32 | #include <lemon/error.h> |
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[1993] | 33 | #include <lemon/bits/invalid.h> |
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[819] | 34 | |
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[921] | 35 | namespace lemon { |
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[819] | 36 | |
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| 37 | /// \addtogroup paths |
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| 38 | /// @{ |
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| 39 | |
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| 40 | |
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[2335] | 41 | /// \brief A structure for representing directed paths in a graph. |
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| 42 | /// |
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| 43 | /// A structure for representing directed path in a graph. |
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| 44 | /// \param Graph The graph type in which the path is. |
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| 45 | /// |
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| 46 | /// In a sense, the path can be treated as a list of edges. The |
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| 47 | /// lemon path type stores just this list. As a consequence it |
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| 48 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 49 | /// cannot store the source. |
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| 50 | /// |
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| 51 | /// This implementation is a back and front insertable and erasable |
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| 52 | /// path type. It can be indexed in O(1) time. The front and back |
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| 53 | /// insertion and erasure is amortized O(1) time. The |
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| 54 | /// impelementation is based on two opposite organized vectors. |
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| 55 | template <typename _Graph> |
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[2247] | 56 | class Path { |
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[819] | 57 | public: |
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[2335] | 58 | |
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| 59 | typedef _Graph Graph; |
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[2247] | 60 | typedef typename Graph::Edge Edge; |
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| 61 | |
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[2335] | 62 | /// \brief Default constructor |
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| 63 | /// |
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| 64 | /// Default constructor |
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| 65 | Path() {} |
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[819] | 66 | |
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[2335] | 67 | /// \brief Template copy constructor |
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[2247] | 68 | /// |
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[2335] | 69 | /// This path can be initialized with any other path type. It just |
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| 70 | /// makes a copy of the given path. |
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| 71 | template <typename CPath> |
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| 72 | Path(const CPath& cpath) { |
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| 73 | copyPath(*this, cpath); |
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[819] | 74 | } |
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| 75 | |
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[2335] | 76 | /// \brief Template copy assignment |
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[819] | 77 | /// |
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[2335] | 78 | /// This path can be initialized with any other path type. It just |
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| 79 | /// makes a copy of the given path. |
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| 80 | template <typename CPath> |
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| 81 | Path& operator=(const CPath& cpath) { |
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| 82 | copyPath(*this, cpath); |
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| 83 | return *this; |
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[819] | 84 | } |
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| 85 | |
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[2335] | 86 | /// \brief Lemon style iterator for path edges |
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[2247] | 87 | /// |
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[2335] | 88 | /// This class is used to iterate on the edges of the paths. |
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| 89 | class EdgeIt { |
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[2247] | 90 | friend class Path; |
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| 91 | public: |
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[2335] | 92 | /// \brief Default constructor |
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| 93 | EdgeIt() {} |
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| 94 | /// \brief Invalid constructor |
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| 95 | EdgeIt(Invalid) : path(0), idx(-1) {} |
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| 96 | /// \brief Initializate the constructor to the first edge of path |
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| 97 | EdgeIt(const Path &_path) |
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| 98 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
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[819] | 99 | |
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[2335] | 100 | private: |
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[819] | 101 | |
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[2335] | 102 | EdgeIt(const Path &_path, int _idx) |
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| 103 | : idx(_idx), path(&_path) {} |
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[2247] | 104 | |
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[2335] | 105 | public: |
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| 106 | |
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| 107 | /// \brief Conversion to Edge |
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| 108 | operator const Edge&() const { |
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| 109 | return path->nth(idx); |
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[2247] | 110 | } |
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| 111 | |
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[2335] | 112 | /// \brief Next edge |
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| 113 | EdgeIt& operator++() { |
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| 114 | ++idx; |
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| 115 | if (idx >= path->length()) idx = -1; |
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[2247] | 116 | return *this; |
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| 117 | } |
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| 118 | |
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| 119 | /// \brief Comparison operator |
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[2335] | 120 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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[2247] | 121 | /// \brief Comparison operator |
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[2335] | 122 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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[2247] | 123 | /// \brief Comparison operator |
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[2335] | 124 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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[2247] | 125 | |
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| 126 | private: |
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| 127 | const Path *path; |
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[2335] | 128 | int idx; |
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[2247] | 129 | }; |
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| 130 | |
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[2335] | 131 | /// \brief Length of the path. |
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| 132 | int length() const { return head.size() + tail.size(); } |
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| 133 | /// \brief Returns whether the path is empty. |
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| 134 | bool empty() const { return head.empty() && tail.empty(); } |
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| 135 | |
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| 136 | /// \brief Resets the path to an empty path. |
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| 137 | void clear() { head.clear(); tail.clear(); } |
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| 138 | |
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| 139 | /// \brief Gives back the nth edge. |
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| 140 | /// |
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| 141 | /// \pre n is in the [0..length() - 1] range |
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| 142 | const Edge& nth(int n) const { |
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[2386] | 143 | return n < int(head.size()) ? *(head.rbegin() + n) : |
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[2335] | 144 | *(tail.begin() + (n - head.size())); |
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| 145 | } |
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| 146 | |
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| 147 | /// \brief Initializes edge iterator to point to the nth edge |
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| 148 | /// |
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| 149 | /// \pre n is in the [0..length() - 1] range |
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| 150 | EdgeIt nthIt(int n) const { |
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| 151 | return EdgeIt(*this, n); |
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| 152 | } |
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| 153 | |
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| 154 | /// \brief Gives back the first edge of the path |
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| 155 | const Edge& front() const { |
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| 156 | return head.empty() ? tail.front() : head.back(); |
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| 157 | } |
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| 158 | |
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| 159 | /// \brief Add a new edge before the current path |
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| 160 | void addFront(const Edge& edge) { |
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| 161 | head.push_back(edge); |
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| 162 | } |
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| 163 | |
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| 164 | /// \brief Erase the first edge of the path |
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| 165 | void eraseFront() { |
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| 166 | if (!head.empty()) { |
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| 167 | head.pop_back(); |
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| 168 | } else { |
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| 169 | head.clear(); |
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| 170 | int halfsize = tail.size() / 2; |
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| 171 | head.resize(halfsize); |
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| 172 | std::copy(tail.begin() + 1, tail.begin() + halfsize + 1, |
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| 173 | head.rbegin()); |
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| 174 | std::copy(tail.begin() + halfsize + 1, tail.end(), tail.begin()); |
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| 175 | tail.resize(tail.size() - halfsize - 1); |
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| 176 | } |
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| 177 | } |
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| 178 | |
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| 179 | /// \brief Gives back the last edge of the path |
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| 180 | const Edge& back() const { |
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| 181 | return tail.empty() ? head.front() : tail.back(); |
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| 182 | } |
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| 183 | |
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| 184 | /// \brief Add a new edge behind the current path |
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| 185 | void addBack(const Edge& edge) { |
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| 186 | tail.push_back(edge); |
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| 187 | } |
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| 188 | |
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| 189 | /// \brief Erase the last edge of the path |
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| 190 | void eraseBack() { |
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| 191 | if (!tail.empty()) { |
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| 192 | tail.pop_back(); |
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| 193 | } else { |
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| 194 | int halfsize = head.size() / 2; |
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| 195 | tail.resize(halfsize); |
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| 196 | std::copy(head.begin() + 1, head.begin() + halfsize + 1, |
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| 197 | tail.rbegin()); |
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| 198 | std::copy(head.begin() + halfsize + 1, head.end(), head.begin()); |
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| 199 | head.resize(head.size() - halfsize - 1); |
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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 | |
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| 205 | typedef True BuildTag; |
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| 206 | |
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| 207 | template <typename CPath> |
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| 208 | void build(const CPath& path) { |
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| 209 | int len = path.length(); |
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| 210 | tail.reserve(len); |
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| 211 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
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| 212 | tail.push_back(it); |
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| 213 | } |
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| 214 | } |
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| 215 | |
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| 216 | template <typename CPath> |
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| 217 | void buildRev(const CPath& path) { |
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| 218 | int len = path.length(); |
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| 219 | head.reserve(len); |
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[2357] | 220 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
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[2335] | 221 | head.push_back(it); |
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| 222 | } |
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| 223 | } |
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| 224 | |
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| 225 | protected: |
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| 226 | typedef std::vector<Edge> Container; |
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| 227 | Container head, tail; |
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| 228 | |
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| 229 | }; |
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| 230 | |
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| 231 | /// \brief A structure for representing directed paths in a graph. |
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| 232 | /// |
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| 233 | /// A structure for representing directed path in a graph. |
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| 234 | /// \param Graph The graph type in which the path is. |
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| 235 | /// |
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| 236 | /// In a sense, the path can be treated as a list of edges. The |
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| 237 | /// lemon path type stores just this list. As a consequence it |
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| 238 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 239 | /// cannot store the source. |
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| 240 | /// |
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| 241 | /// This implementation is a just back insertable and erasable path |
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| 242 | /// type. It can be indexed in O(1) time. The back insertion and |
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| 243 | /// erasure is amortized O(1) time. This implementation is faster |
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| 244 | /// then the \c Path type because it use just one vector for the |
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| 245 | /// edges. |
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| 246 | template <typename _Graph> |
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| 247 | class SimplePath { |
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| 248 | public: |
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| 249 | |
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| 250 | typedef _Graph Graph; |
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| 251 | typedef typename Graph::Edge Edge; |
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| 252 | |
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| 253 | /// \brief Default constructor |
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| 254 | /// |
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| 255 | /// Default constructor |
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| 256 | SimplePath() {} |
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| 257 | |
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| 258 | /// \brief Template copy constructor |
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| 259 | /// |
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| 260 | /// This path can be initialized with any other path type. It just |
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| 261 | /// makes a copy of the given path. |
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| 262 | template <typename CPath> |
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| 263 | SimplePath(const CPath& cpath) { |
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| 264 | copyPath(*this, cpath); |
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| 265 | } |
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| 266 | |
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| 267 | /// \brief Template copy assignment |
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| 268 | /// |
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| 269 | /// This path can be initialized with any other path type. It just |
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| 270 | /// makes a copy of the given path. |
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| 271 | template <typename CPath> |
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| 272 | SimplePath& operator=(const CPath& cpath) { |
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| 273 | copyPath(*this, cpath); |
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| 274 | return *this; |
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| 275 | } |
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| 276 | |
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[2247] | 277 | /// \brief Iterator class to iterate on the edges of the paths |
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| 278 | /// |
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| 279 | /// This class is used to iterate on the edges of the paths |
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[2335] | 280 | /// |
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[2247] | 281 | /// Of course it converts to Graph::Edge |
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[819] | 282 | class EdgeIt { |
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[2335] | 283 | friend class SimplePath; |
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| 284 | public: |
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| 285 | /// Default constructor |
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| 286 | EdgeIt() {} |
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| 287 | /// Invalid constructor |
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| 288 | EdgeIt(Invalid) : path(0), idx(-1) {} |
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| 289 | /// \brief Initializate the constructor to the first edge of path |
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| 290 | EdgeIt(const SimplePath &_path) |
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| 291 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
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| 292 | |
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| 293 | private: |
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| 294 | |
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| 295 | /// Constructor with starting point |
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| 296 | EdgeIt(const SimplePath &_path, int _idx) |
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| 297 | : idx(_idx), path(&_path) {} |
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| 298 | |
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[2247] | 299 | public: |
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[819] | 300 | |
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[2335] | 301 | ///Conversion to Graph::Edge |
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| 302 | operator const Edge&() const { |
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| 303 | return path->nth(idx); |
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[819] | 304 | } |
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| 305 | |
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[2335] | 306 | /// Next edge |
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[2247] | 307 | EdgeIt& operator++() { |
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[2335] | 308 | ++idx; |
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| 309 | if (idx >= path->length()) idx = -1; |
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[2247] | 310 | return *this; |
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| 311 | } |
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| 312 | |
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[819] | 313 | /// Comparison operator |
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[2335] | 314 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
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| 315 | /// Comparison operator |
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| 316 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
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| 317 | /// Comparison operator |
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| 318 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
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[2247] | 319 | |
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[2335] | 320 | private: |
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| 321 | const SimplePath *path; |
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| 322 | int idx; |
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| 323 | }; |
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| 324 | |
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| 325 | /// \brief Length of the path. |
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| 326 | int length() const { return data.size(); } |
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| 327 | /// \brief Returns whether the path is empty. |
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| 328 | bool empty() const { return data.empty(); } |
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| 329 | |
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| 330 | /// \brief Resets the path to an empty path. |
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| 331 | void clear() { data.clear(); } |
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| 332 | |
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| 333 | /// \brief Gives back the nth edge. |
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| 334 | /// |
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| 335 | /// \pre n is in the [0..length() - 1] range |
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| 336 | const Edge& nth(int n) const { |
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| 337 | return data[n]; |
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| 338 | } |
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| 339 | |
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| 340 | /// \brief Initializes edge iterator to point to the nth edge. |
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| 341 | EdgeIt nthIt(int n) const { |
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| 342 | return EdgeIt(*this, n); |
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| 343 | } |
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| 344 | |
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| 345 | /// \brief Gives back the last edge of the path. |
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| 346 | const Edge& back() const { |
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| 347 | return data.back(); |
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| 348 | } |
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| 349 | |
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| 350 | /// \brief Add a new edge behind the current path. |
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| 351 | void addBack(const Edge& edge) { |
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| 352 | data.push_back(edge); |
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| 353 | } |
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| 354 | |
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| 355 | /// \brief Erase the last edge of the path |
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| 356 | void eraseBack() { |
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| 357 | data.pop_back(); |
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| 358 | } |
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| 359 | |
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| 360 | typedef True BuildTag; |
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| 361 | |
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| 362 | template <typename CPath> |
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| 363 | void build(const CPath& path) { |
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| 364 | int len = path.length(); |
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| 365 | data.resize(len); |
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| 366 | int index = 0; |
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| 367 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
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| 368 | data[index] = it;; |
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| 369 | ++index; |
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| 370 | } |
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| 371 | } |
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| 372 | |
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| 373 | template <typename CPath> |
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| 374 | void buildRev(const CPath& path) { |
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| 375 | int len = path.length(); |
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| 376 | data.resize(len); |
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| 377 | int index = len; |
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[2357] | 378 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
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[2335] | 379 | --index; |
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| 380 | data[index] = it;; |
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| 381 | } |
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| 382 | } |
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| 383 | |
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| 384 | protected: |
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| 385 | typedef std::vector<Edge> Container; |
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| 386 | Container data; |
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| 387 | |
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| 388 | }; |
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| 389 | |
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| 390 | /// \brief A structure for representing directed paths in a graph. |
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| 391 | /// |
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| 392 | /// A structure for representing directed path in a graph. |
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| 393 | /// \param Graph The graph type in which the path is. |
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| 394 | /// |
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| 395 | /// In a sense, the path can be treated as a list of edges. The |
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| 396 | /// lemon path type stores just this list. As a consequence it |
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| 397 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 398 | /// cannot store the source. |
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| 399 | /// |
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| 400 | /// This implementation is a back and front insertable and erasable |
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| 401 | /// path type. It can be indexed in O(k) time, where k is the rank |
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| 402 | /// of the edge in the path. The length can be computed in O(n) |
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| 403 | /// time. The front and back insertion and erasure is O(1) time |
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| 404 | /// and it can be splited and spliced in O(1) time. |
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| 405 | template <typename _Graph> |
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| 406 | class ListPath { |
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| 407 | public: |
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| 408 | |
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| 409 | typedef _Graph Graph; |
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| 410 | typedef typename Graph::Edge Edge; |
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| 411 | |
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| 412 | protected: |
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| 413 | |
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| 414 | // the std::list<> is incompatible |
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| 415 | // hard to create invalid iterator |
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| 416 | struct Node { |
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| 417 | Edge edge; |
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| 418 | Node *next, *prev; |
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| 419 | }; |
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| 420 | |
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| 421 | Node *first, *last; |
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| 422 | |
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| 423 | std::allocator<Node> alloc; |
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| 424 | |
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| 425 | public: |
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| 426 | |
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| 427 | /// \brief Default constructor |
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| 428 | /// |
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| 429 | /// Default constructor |
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| 430 | ListPath() : first(0), last(0) {} |
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| 431 | |
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| 432 | /// \brief Template copy constructor |
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| 433 | /// |
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| 434 | /// This path can be initialized with any other path type. It just |
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| 435 | /// makes a copy of the given path. |
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| 436 | template <typename CPath> |
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| 437 | ListPath(const CPath& cpath) : first(0), last(0) { |
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| 438 | copyPath(*this, cpath); |
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| 439 | } |
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| 440 | |
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| 441 | /// \brief Destructor of the path |
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| 442 | /// |
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| 443 | /// Destructor of the path |
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| 444 | ~ListPath() { |
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| 445 | clear(); |
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| 446 | } |
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| 447 | |
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| 448 | /// \brief Template copy assignment |
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| 449 | /// |
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| 450 | /// This path can be initialized with any other path type. It just |
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| 451 | /// makes a copy of the given path. |
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| 452 | template <typename CPath> |
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| 453 | ListPath& operator=(const CPath& cpath) { |
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| 454 | copyPath(*this, cpath); |
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| 455 | return *this; |
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| 456 | } |
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| 457 | |
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| 458 | /// \brief Iterator class to iterate on the edges of the paths |
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| 459 | /// |
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| 460 | /// This class is used to iterate on the edges of the paths |
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| 461 | /// |
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| 462 | /// Of course it converts to Graph::Edge |
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| 463 | class EdgeIt { |
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| 464 | friend class ListPath; |
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| 465 | public: |
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| 466 | /// Default constructor |
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| 467 | EdgeIt() {} |
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| 468 | /// Invalid constructor |
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| 469 | EdgeIt(Invalid) : path(0), node(0) {} |
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| 470 | /// \brief Initializate the constructor to the first edge of path |
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| 471 | EdgeIt(const ListPath &_path) |
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| 472 | : path(&_path), node(_path.first) {} |
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| 473 | |
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| 474 | protected: |
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| 475 | |
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| 476 | EdgeIt(const ListPath &_path, Node *_node) |
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| 477 | : path(&_path), node(_node) {} |
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| 478 | |
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| 479 | |
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| 480 | public: |
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| 481 | |
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| 482 | ///Conversion to Graph::Edge |
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| 483 | operator const Edge&() const { |
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| 484 | return node->edge; |
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| 485 | } |
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| 486 | |
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| 487 | /// Next edge |
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| 488 | EdgeIt& operator++() { |
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| 489 | node = node->next; |
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| 490 | return *this; |
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| 491 | } |
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| 492 | |
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[819] | 493 | /// Comparison operator |
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[2335] | 494 | bool operator==(const EdgeIt& e) const { return node==e.node; } |
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| 495 | /// Comparison operator |
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| 496 | bool operator!=(const EdgeIt& e) const { return node!=e.node; } |
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| 497 | /// Comparison operator |
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| 498 | bool operator<(const EdgeIt& e) const { return node<e.node; } |
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[2247] | 499 | |
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[2335] | 500 | private: |
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| 501 | const ListPath *path; |
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| 502 | Node *node; |
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| 503 | }; |
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| 504 | |
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| 505 | /// \brief Gives back the nth edge. |
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| 506 | /// |
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| 507 | /// Gives back the nth edge in O(n) time. |
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| 508 | /// \pre n is in the [0..length() - 1] range |
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| 509 | const Edge& nth(int n) const { |
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| 510 | Node *node = first; |
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| 511 | for (int i = 0; i < n; ++i) { |
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| 512 | node = node->next; |
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| 513 | } |
---|
| 514 | return node->edge; |
---|
| 515 | } |
---|
| 516 | |
---|
| 517 | /// \brief Initializes edge iterator to point to the nth edge. |
---|
| 518 | EdgeIt nthIt(int n) const { |
---|
| 519 | Node *node = first; |
---|
| 520 | for (int i = 0; i < n; ++i) { |
---|
| 521 | node = node->next; |
---|
| 522 | } |
---|
| 523 | return EdgeIt(*this, node); |
---|
| 524 | } |
---|
| 525 | |
---|
| 526 | /// \brief Length of the path. |
---|
| 527 | int length() const { |
---|
| 528 | int len = 0; |
---|
| 529 | Node *node = first; |
---|
| 530 | while (node != 0) { |
---|
| 531 | node = node->next; |
---|
| 532 | ++len; |
---|
| 533 | } |
---|
| 534 | return len; |
---|
| 535 | } |
---|
| 536 | |
---|
| 537 | /// \brief Returns whether the path is empty. |
---|
| 538 | bool empty() const { return first == 0; } |
---|
| 539 | |
---|
| 540 | /// \brief Resets the path to an empty path. |
---|
| 541 | void clear() { |
---|
| 542 | while (first != 0) { |
---|
| 543 | last = first->next; |
---|
| 544 | alloc.destroy(first); |
---|
| 545 | alloc.deallocate(first, 1); |
---|
| 546 | first = last; |
---|
| 547 | } |
---|
| 548 | } |
---|
| 549 | |
---|
| 550 | /// \brief Gives back the first edge of the path |
---|
| 551 | const Edge& front() const { |
---|
| 552 | return first->edge; |
---|
| 553 | } |
---|
| 554 | |
---|
| 555 | /// \brief Add a new edge before the current path |
---|
| 556 | void addFront(const Edge& edge) { |
---|
| 557 | Node *node = alloc.allocate(1); |
---|
| 558 | alloc.construct(node, Node()); |
---|
| 559 | node->prev = 0; |
---|
| 560 | node->next = first; |
---|
| 561 | node->edge = edge; |
---|
| 562 | if (first) { |
---|
| 563 | first->prev = node; |
---|
| 564 | first = node; |
---|
| 565 | } else { |
---|
| 566 | first = last = node; |
---|
| 567 | } |
---|
| 568 | } |
---|
| 569 | |
---|
| 570 | /// \brief Erase the first edge of the path |
---|
| 571 | void eraseFront() { |
---|
| 572 | Node *node = first; |
---|
| 573 | first = first->next; |
---|
| 574 | if (first) { |
---|
| 575 | first->prev = 0; |
---|
| 576 | } else { |
---|
| 577 | last = 0; |
---|
| 578 | } |
---|
| 579 | alloc.destroy(node); |
---|
| 580 | alloc.deallocate(node, 1); |
---|
| 581 | } |
---|
| 582 | |
---|
| 583 | /// \brief Gives back the last edge of the path. |
---|
| 584 | const Edge& back() const { |
---|
| 585 | return last->edge; |
---|
| 586 | } |
---|
| 587 | |
---|
| 588 | /// \brief Add a new edge behind the current path. |
---|
| 589 | void addBack(const Edge& edge) { |
---|
| 590 | Node *node = alloc.allocate(1); |
---|
| 591 | alloc.construct(node, Node()); |
---|
| 592 | node->next = 0; |
---|
| 593 | node->prev = last; |
---|
| 594 | node->edge = edge; |
---|
| 595 | if (last) { |
---|
| 596 | last->next = node; |
---|
| 597 | last = node; |
---|
| 598 | } else { |
---|
| 599 | last = first = node; |
---|
| 600 | } |
---|
| 601 | } |
---|
| 602 | |
---|
| 603 | /// \brief Erase the last edge of the path |
---|
| 604 | void eraseBack() { |
---|
| 605 | Node *node = last; |
---|
| 606 | last = last->prev; |
---|
| 607 | if (last) { |
---|
| 608 | last->next = 0; |
---|
| 609 | } else { |
---|
| 610 | first = 0; |
---|
| 611 | } |
---|
| 612 | alloc.destroy(node); |
---|
| 613 | alloc.deallocate(node, 1); |
---|
| 614 | } |
---|
| 615 | |
---|
| 616 | /// \brief Splicing the given path to the current path. |
---|
| 617 | /// |
---|
| 618 | /// It splices the \c tpath to the back of the current path and \c |
---|
| 619 | /// tpath becomes empty. The time complexity of this function is |
---|
| 620 | /// O(1). |
---|
| 621 | void spliceBack(ListPath& tpath) { |
---|
| 622 | if (first) { |
---|
| 623 | if (tpath.first) { |
---|
| 624 | last->next = tpath.first; |
---|
| 625 | tpath.first->prev = last; |
---|
| 626 | last = tpath.last; |
---|
| 627 | } |
---|
| 628 | } else { |
---|
| 629 | first = tpath.first; |
---|
| 630 | last = tpath.last; |
---|
| 631 | } |
---|
| 632 | tpath.first = tpath.last = 0; |
---|
| 633 | } |
---|
| 634 | |
---|
| 635 | /// \brief Splicing the given path to the current path. |
---|
| 636 | /// |
---|
| 637 | /// It splices the \c tpath before the current path and \c tpath |
---|
| 638 | /// becomes empty. The time complexity of this function |
---|
| 639 | /// is O(1). |
---|
| 640 | void spliceFront(ListPath& tpath) { |
---|
| 641 | if (first) { |
---|
| 642 | if (tpath.first) { |
---|
| 643 | first->prev = tpath.last; |
---|
| 644 | tpath.last->next = first; |
---|
| 645 | first = tpath.first; |
---|
| 646 | } |
---|
| 647 | } else { |
---|
| 648 | first = tpath.first; |
---|
| 649 | last = tpath.last; |
---|
| 650 | } |
---|
| 651 | tpath.first = tpath.last = 0; |
---|
| 652 | } |
---|
| 653 | |
---|
| 654 | /// \brief Splicing the given path into the current path. |
---|
| 655 | /// |
---|
| 656 | /// It splices the \c tpath into the current path before the |
---|
| 657 | /// position of \c it iterator and \c tpath becomes empty. The |
---|
| 658 | /// time complexity of this function is O(1). If the \c it is \c |
---|
| 659 | /// INVALID then it will splice behind the current path. |
---|
| 660 | void splice(EdgeIt it, ListPath& tpath) { |
---|
| 661 | if (it.node) { |
---|
| 662 | if (tpath.first) { |
---|
| 663 | tpath.first->prev = it.node->prev; |
---|
| 664 | if (it.node->prev) { |
---|
| 665 | it.node->prev->next = tpath.first; |
---|
| 666 | } else { |
---|
| 667 | first = tpath.first; |
---|
| 668 | } |
---|
| 669 | it.node->prev = tpath.last; |
---|
| 670 | tpath.last->next = it.node; |
---|
| 671 | } |
---|
| 672 | } else { |
---|
| 673 | if (first) { |
---|
| 674 | if (tpath.first) { |
---|
| 675 | last->next = tpath.first; |
---|
| 676 | tpath.first->prev = last; |
---|
| 677 | last = tpath.last; |
---|
| 678 | } |
---|
| 679 | } else { |
---|
| 680 | first = tpath.first; |
---|
| 681 | last = tpath.last; |
---|
| 682 | } |
---|
| 683 | } |
---|
| 684 | tpath.first = tpath.last = 0; |
---|
| 685 | } |
---|
| 686 | |
---|
| 687 | /// \brief Spliting the current path. |
---|
| 688 | /// |
---|
| 689 | /// It splits the current path into two parts. The part before \c |
---|
| 690 | /// it iterator will remain in the current path and the part from |
---|
| 691 | /// the it will put into the \c tpath. If the \c tpath had edges |
---|
| 692 | /// before the operation they will be removed first. The time |
---|
| 693 | /// complexity of this function is O(1) plus the clearing of \c |
---|
| 694 | /// tpath. If the \c it is \c INVALID then it just clears \c |
---|
| 695 | /// tpath. |
---|
| 696 | void split(EdgeIt it, ListPath& tpath) { |
---|
| 697 | tpath.clear(); |
---|
| 698 | if (it.node) { |
---|
| 699 | tpath.first = it.node; |
---|
| 700 | tpath.last = last; |
---|
| 701 | if (it.node->prev) { |
---|
| 702 | last = it.node->prev; |
---|
| 703 | last->next = 0; |
---|
| 704 | } else { |
---|
| 705 | first = last = 0; |
---|
| 706 | } |
---|
| 707 | it.node->prev = 0; |
---|
| 708 | } |
---|
| 709 | } |
---|
| 710 | |
---|
| 711 | |
---|
| 712 | typedef True BuildTag; |
---|
| 713 | |
---|
| 714 | template <typename CPath> |
---|
| 715 | void build(const CPath& path) { |
---|
| 716 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
---|
| 717 | addBack(it); |
---|
| 718 | } |
---|
| 719 | } |
---|
| 720 | |
---|
| 721 | template <typename CPath> |
---|
| 722 | void buildRev(const CPath& path) { |
---|
[2357] | 723 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
---|
[2335] | 724 | addFront(it); |
---|
| 725 | } |
---|
| 726 | } |
---|
| 727 | |
---|
| 728 | }; |
---|
| 729 | |
---|
| 730 | /// \brief A structure for representing directed paths in a graph. |
---|
| 731 | /// |
---|
| 732 | /// A structure for representing directed path in a graph. |
---|
| 733 | /// \param Graph The graph type in which the path is. |
---|
| 734 | /// |
---|
| 735 | /// In a sense, the path can be treated as a list of edges. The |
---|
| 736 | /// lemon path type stores just this list. As a consequence it |
---|
| 737 | /// cannot enumerate the nodes in the path and the zero length paths |
---|
| 738 | /// cannot store the source. |
---|
| 739 | /// |
---|
| 740 | /// This implementation is completly static, so it cannot be |
---|
| 741 | /// modified exclude the assign an other path. It is intented to be |
---|
[2336] | 742 | /// used when you want to store a large number of paths because it is |
---|
[2335] | 743 | /// the most memory efficient path type in the lemon. |
---|
| 744 | template <typename _Graph> |
---|
| 745 | class StaticPath { |
---|
| 746 | public: |
---|
| 747 | |
---|
| 748 | typedef _Graph Graph; |
---|
| 749 | typedef typename Graph::Edge Edge; |
---|
| 750 | |
---|
| 751 | /// \brief Default constructor |
---|
| 752 | /// |
---|
| 753 | /// Default constructor |
---|
| 754 | StaticPath() : len(0), edges(0) {} |
---|
| 755 | |
---|
| 756 | /// \brief Template copy constructor |
---|
| 757 | /// |
---|
| 758 | /// This path can be initialized with any other path type. It just |
---|
| 759 | /// makes a copy of the given path. |
---|
| 760 | template <typename CPath> |
---|
| 761 | StaticPath(const CPath& cpath) : edges(0) { |
---|
| 762 | copyPath(*this, cpath); |
---|
| 763 | } |
---|
| 764 | |
---|
| 765 | /// \brief Destructor of the path |
---|
| 766 | /// |
---|
| 767 | /// Destructor of the path |
---|
| 768 | ~StaticPath() { |
---|
| 769 | if (edges) delete[] edges; |
---|
| 770 | } |
---|
| 771 | |
---|
| 772 | /// \brief Template copy assignment |
---|
| 773 | /// |
---|
| 774 | /// This path can be initialized with any other path type. It just |
---|
| 775 | /// makes a copy of the given path. |
---|
| 776 | template <typename CPath> |
---|
| 777 | StaticPath& operator=(const CPath& cpath) { |
---|
| 778 | copyPath(*this, cpath); |
---|
| 779 | return *this; |
---|
| 780 | } |
---|
| 781 | |
---|
| 782 | /// \brief Iterator class to iterate on the edges of the paths |
---|
| 783 | /// |
---|
| 784 | /// This class is used to iterate on the edges of the paths |
---|
| 785 | /// |
---|
| 786 | /// Of course it converts to Graph::Edge |
---|
| 787 | class EdgeIt { |
---|
| 788 | friend class StaticPath; |
---|
| 789 | public: |
---|
| 790 | /// Default constructor |
---|
| 791 | EdgeIt() {} |
---|
| 792 | /// Invalid constructor |
---|
| 793 | EdgeIt(Invalid) : path(0), idx(-1) {} |
---|
| 794 | /// Initializate the constructor to the first edge of path |
---|
| 795 | EdgeIt(const StaticPath &_path) |
---|
| 796 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
---|
[819] | 797 | |
---|
| 798 | private: |
---|
[2247] | 799 | |
---|
[2335] | 800 | /// Constructor with starting point |
---|
| 801 | EdgeIt(const StaticPath &_path, int _idx) |
---|
| 802 | : idx(_idx), path(&_path) {} |
---|
| 803 | |
---|
| 804 | public: |
---|
| 805 | |
---|
| 806 | ///Conversion to Graph::Edge |
---|
| 807 | operator const Edge&() const { |
---|
| 808 | return path->nth(idx); |
---|
| 809 | } |
---|
| 810 | |
---|
| 811 | /// Next edge |
---|
| 812 | EdgeIt& operator++() { |
---|
| 813 | ++idx; |
---|
| 814 | if (idx >= path->length()) idx = -1; |
---|
| 815 | return *this; |
---|
| 816 | } |
---|
| 817 | |
---|
| 818 | /// Comparison operator |
---|
| 819 | bool operator==(const EdgeIt& e) const { return idx==e.idx; } |
---|
| 820 | /// Comparison operator |
---|
| 821 | bool operator!=(const EdgeIt& e) const { return idx!=e.idx; } |
---|
| 822 | /// Comparison operator |
---|
| 823 | bool operator<(const EdgeIt& e) const { return idx<e.idx; } |
---|
| 824 | |
---|
| 825 | private: |
---|
| 826 | const StaticPath *path; |
---|
| 827 | int idx; |
---|
[819] | 828 | }; |
---|
| 829 | |
---|
[2335] | 830 | /// \brief Gives back the nth edge. |
---|
| 831 | /// |
---|
| 832 | /// \pre n is in the [0..length() - 1] range |
---|
| 833 | const Edge& nth(int n) const { |
---|
| 834 | return edges[n]; |
---|
| 835 | } |
---|
[819] | 836 | |
---|
[2335] | 837 | /// \brief Initializes edge iterator to point to the nth edge. |
---|
| 838 | EdgeIt nthIt(int n) const { |
---|
| 839 | return EdgeIt(*this, n); |
---|
| 840 | } |
---|
[819] | 841 | |
---|
[2335] | 842 | /// \brief Gives back the length of the path. |
---|
| 843 | int length() const { return len; } |
---|
[819] | 844 | |
---|
[2335] | 845 | /// \brief Returns true when the path is empty. |
---|
| 846 | int empty() const { return len == 0; } |
---|
[819] | 847 | |
---|
[2335] | 848 | /// \break Erase all edge in the graph. |
---|
| 849 | void clear() { |
---|
| 850 | len = 0; |
---|
| 851 | if (edges) delete[] edges; |
---|
| 852 | edges = 0; |
---|
| 853 | } |
---|
[819] | 854 | |
---|
[2335] | 855 | /// \brief Gives back the first edge of the path. |
---|
| 856 | const Edge& front() const { |
---|
| 857 | return edges[0]; |
---|
| 858 | } |
---|
[819] | 859 | |
---|
[2335] | 860 | /// \brief Gives back the last edge of the path. |
---|
| 861 | const Edge& back() const { |
---|
| 862 | return edges[len - 1]; |
---|
| 863 | } |
---|
| 864 | |
---|
| 865 | |
---|
| 866 | typedef True BuildTag; |
---|
| 867 | |
---|
| 868 | template <typename CPath> |
---|
| 869 | void build(const CPath& path) { |
---|
| 870 | len = path.length(); |
---|
| 871 | edges = new Edge[len]; |
---|
| 872 | int index = 0; |
---|
| 873 | for (typename CPath::EdgeIt it(path); it != INVALID; ++it) { |
---|
| 874 | edges[index] = it; |
---|
| 875 | ++index; |
---|
[2247] | 876 | } |
---|
[2335] | 877 | } |
---|
[819] | 878 | |
---|
[2335] | 879 | template <typename CPath> |
---|
| 880 | void buildRev(const CPath& path) { |
---|
| 881 | len = path.length(); |
---|
| 882 | edges = new Edge[len]; |
---|
| 883 | int index = len; |
---|
[2357] | 884 | for (typename CPath::RevEdgeIt it(path); it != INVALID; ++it) { |
---|
[2335] | 885 | --index; |
---|
| 886 | edges[index] = it; |
---|
[2247] | 887 | } |
---|
[2335] | 888 | } |
---|
[837] | 889 | |
---|
[2335] | 890 | private: |
---|
| 891 | int len; |
---|
| 892 | Edge* edges; |
---|
[819] | 893 | }; |
---|
| 894 | |
---|
| 895 | ///@} |
---|
| 896 | |
---|
[921] | 897 | } // namespace lemon |
---|
[819] | 898 | |
---|
[921] | 899 | #endif // LEMON_PATH_H |
---|