[209] | 1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
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[96] | 2 | * |
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[209] | 3 | * This file is a part of LEMON, a generic C++ optimization library. |
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[96] | 4 | * |
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| 5 | * Copyright (C) 2003-2008 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 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 digraphs. |
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| 22 | /// |
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| 23 | |
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| 24 | #ifndef LEMON_PATH_H |
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| 25 | #define LEMON_PATH_H |
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| 26 | |
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| 27 | #include <vector> |
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| 28 | #include <algorithm> |
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| 29 | |
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| 30 | #include <lemon/error.h> |
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[220] | 31 | #include <lemon/core.h> |
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[100] | 32 | #include <lemon/concepts/path.h> |
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[96] | 33 | |
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| 34 | namespace lemon { |
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| 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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| 40 | /// \brief A structure for representing directed paths in a digraph. |
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| 41 | /// |
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| 42 | /// A structure for representing directed path in a digraph. |
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[157] | 43 | /// \tparam _Digraph The digraph type in which the path is. |
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[96] | 44 | /// |
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| 45 | /// In a sense, the path can be treated as a list of arcs. The |
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[97] | 46 | /// lemon path type stores just this list. As a consequence, it |
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| 47 | /// cannot enumerate the nodes of the path and the source node of |
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| 48 | /// a zero length path is undefined. |
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[96] | 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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[97] | 52 | /// insertion and erase is done in O(1) (amortized) time. The |
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| 53 | /// implementation uses two vectors for storing the front and back |
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| 54 | /// insertions. |
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[96] | 55 | template <typename _Digraph> |
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| 56 | class Path { |
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| 57 | public: |
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| 58 | |
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| 59 | typedef _Digraph Digraph; |
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| 60 | typedef typename Digraph::Arc Arc; |
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| 61 | |
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| 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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| 66 | |
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| 67 | /// \brief Template copy constructor |
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| 68 | /// |
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[97] | 69 | /// This constuctor initializes the path from any other path type. |
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| 70 | /// It simply makes a copy of the given path. |
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[96] | 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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| 74 | } |
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| 75 | |
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| 76 | /// \brief Template copy assignment |
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| 77 | /// |
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[97] | 78 | /// This operator makes a copy of a path of any other type. |
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[96] | 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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| 83 | } |
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| 84 | |
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[236] | 85 | /// \brief LEMON style iterator for path arcs |
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[96] | 86 | /// |
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| 87 | /// This class is used to iterate on the arcs of the paths. |
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| 88 | class ArcIt { |
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| 89 | friend class Path; |
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| 90 | public: |
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| 91 | /// \brief Default constructor |
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| 92 | ArcIt() {} |
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| 93 | /// \brief Invalid constructor |
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| 94 | ArcIt(Invalid) : path(0), idx(-1) {} |
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[97] | 95 | /// \brief Initializate the iterator to the first arc of path |
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[209] | 96 | ArcIt(const Path &_path) |
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[96] | 97 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
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| 98 | |
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| 99 | private: |
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| 100 | |
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[209] | 101 | ArcIt(const Path &_path, int _idx) |
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[96] | 102 | : path(&_path), idx(_idx) {} |
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| 103 | |
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| 104 | public: |
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| 105 | |
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| 106 | /// \brief Conversion to Arc |
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| 107 | operator const Arc&() const { |
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| 108 | return path->nth(idx); |
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| 109 | } |
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| 110 | |
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| 111 | /// \brief Next arc |
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[209] | 112 | ArcIt& operator++() { |
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[96] | 113 | ++idx; |
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[209] | 114 | if (idx >= path->length()) idx = -1; |
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| 115 | return *this; |
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[96] | 116 | } |
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| 117 | |
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| 118 | /// \brief Comparison operator |
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| 119 | bool operator==(const ArcIt& e) const { return idx==e.idx; } |
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| 120 | /// \brief Comparison operator |
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| 121 | bool operator!=(const ArcIt& e) const { return idx!=e.idx; } |
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| 122 | /// \brief Comparison operator |
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| 123 | bool operator<(const ArcIt& e) const { return idx<e.idx; } |
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| 124 | |
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| 125 | private: |
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| 126 | const Path *path; |
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| 127 | int idx; |
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| 128 | }; |
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| 129 | |
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| 130 | /// \brief Length of the path. |
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| 131 | int length() const { return head.size() + tail.size(); } |
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[97] | 132 | /// \brief Return whether the path is empty. |
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[96] | 133 | bool empty() const { return head.empty() && tail.empty(); } |
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| 134 | |
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[97] | 135 | /// \brief Reset the path to an empty one. |
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[96] | 136 | void clear() { head.clear(); tail.clear(); } |
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| 137 | |
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[97] | 138 | /// \brief The nth arc. |
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[96] | 139 | /// |
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| 140 | /// \pre n is in the [0..length() - 1] range |
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| 141 | const Arc& nth(int n) const { |
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| 142 | return n < int(head.size()) ? *(head.rbegin() + n) : |
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| 143 | *(tail.begin() + (n - head.size())); |
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| 144 | } |
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| 145 | |
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[97] | 146 | /// \brief Initialize arc iterator to point to the nth arc |
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[96] | 147 | /// |
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| 148 | /// \pre n is in the [0..length() - 1] range |
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| 149 | ArcIt nthIt(int n) const { |
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| 150 | return ArcIt(*this, n); |
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| 151 | } |
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| 152 | |
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[97] | 153 | /// \brief The first arc of the path |
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[96] | 154 | const Arc& 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 arc before the current path |
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| 159 | void addFront(const Arc& arc) { |
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| 160 | head.push_back(arc); |
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| 161 | } |
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| 162 | |
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| 163 | /// \brief Erase the first arc 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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[97] | 178 | /// \brief The last arc of the path |
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[96] | 179 | const Arc& 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 arc behind the current path |
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| 184 | void addBack(const Arc& arc) { |
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| 185 | tail.push_back(arc); |
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| 186 | } |
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| 187 | |
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| 188 | /// \brief Erase the last arc 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 | typedef True BuildTag; |
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| 203 | |
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| 204 | template <typename CPath> |
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| 205 | void build(const CPath& path) { |
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| 206 | int len = path.length(); |
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| 207 | tail.reserve(len); |
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| 208 | for (typename CPath::ArcIt it(path); it != INVALID; ++it) { |
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| 209 | tail.push_back(it); |
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| 210 | } |
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| 211 | } |
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| 212 | |
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| 213 | template <typename CPath> |
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| 214 | void buildRev(const CPath& path) { |
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| 215 | int len = path.length(); |
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| 216 | head.reserve(len); |
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| 217 | for (typename CPath::RevArcIt it(path); it != INVALID; ++it) { |
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| 218 | head.push_back(it); |
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| 219 | } |
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| 220 | } |
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| 221 | |
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| 222 | protected: |
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| 223 | typedef std::vector<Arc> Container; |
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| 224 | Container head, tail; |
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| 225 | |
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| 226 | }; |
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| 227 | |
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| 228 | /// \brief A structure for representing directed paths in a digraph. |
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| 229 | /// |
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| 230 | /// A structure for representing directed path in a digraph. |
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[157] | 231 | /// \tparam _Digraph The digraph type in which the path is. |
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[96] | 232 | /// |
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| 233 | /// In a sense, the path can be treated as a list of arcs. The |
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| 234 | /// lemon path type stores just this list. As a consequence it |
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| 235 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 236 | /// cannot store the source. |
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| 237 | /// |
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| 238 | /// This implementation is a just back insertable and erasable path |
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| 239 | /// type. It can be indexed in O(1) time. The back insertion and |
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| 240 | /// erasure is amortized O(1) time. This implementation is faster |
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| 241 | /// then the \c Path type because it use just one vector for the |
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| 242 | /// arcs. |
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| 243 | template <typename _Digraph> |
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| 244 | class SimplePath { |
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| 245 | public: |
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| 246 | |
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| 247 | typedef _Digraph Digraph; |
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| 248 | typedef typename Digraph::Arc Arc; |
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| 249 | |
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| 250 | /// \brief Default constructor |
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| 251 | /// |
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| 252 | /// Default constructor |
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| 253 | SimplePath() {} |
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| 254 | |
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| 255 | /// \brief Template copy constructor |
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| 256 | /// |
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| 257 | /// This path can be initialized with any other path type. It just |
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| 258 | /// makes a copy of the given path. |
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| 259 | template <typename CPath> |
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| 260 | SimplePath(const CPath& cpath) { |
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| 261 | copyPath(*this, cpath); |
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| 262 | } |
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| 263 | |
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| 264 | /// \brief Template copy assignment |
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| 265 | /// |
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| 266 | /// This path can be initialized with any other path type. It just |
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| 267 | /// makes a copy of the given path. |
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| 268 | template <typename CPath> |
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| 269 | SimplePath& operator=(const CPath& cpath) { |
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| 270 | copyPath(*this, cpath); |
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| 271 | return *this; |
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| 272 | } |
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| 273 | |
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| 274 | /// \brief Iterator class to iterate on the arcs of the paths |
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| 275 | /// |
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| 276 | /// This class is used to iterate on the arcs of the paths |
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| 277 | /// |
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| 278 | /// Of course it converts to Digraph::Arc |
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| 279 | class ArcIt { |
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| 280 | friend class SimplePath; |
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| 281 | public: |
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| 282 | /// Default constructor |
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| 283 | ArcIt() {} |
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| 284 | /// Invalid constructor |
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| 285 | ArcIt(Invalid) : path(0), idx(-1) {} |
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| 286 | /// \brief Initializate the constructor to the first arc of path |
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[209] | 287 | ArcIt(const SimplePath &_path) |
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[96] | 288 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
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| 289 | |
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| 290 | private: |
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| 291 | |
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| 292 | /// Constructor with starting point |
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[209] | 293 | ArcIt(const SimplePath &_path, int _idx) |
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[96] | 294 | : idx(_idx), path(&_path) {} |
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| 295 | |
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| 296 | public: |
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| 297 | |
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| 298 | ///Conversion to Digraph::Arc |
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| 299 | operator const Arc&() const { |
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| 300 | return path->nth(idx); |
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| 301 | } |
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| 302 | |
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| 303 | /// Next arc |
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[209] | 304 | ArcIt& operator++() { |
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[96] | 305 | ++idx; |
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[209] | 306 | if (idx >= path->length()) idx = -1; |
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| 307 | return *this; |
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[96] | 308 | } |
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| 309 | |
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| 310 | /// Comparison operator |
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| 311 | bool operator==(const ArcIt& e) const { return idx==e.idx; } |
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| 312 | /// Comparison operator |
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| 313 | bool operator!=(const ArcIt& e) const { return idx!=e.idx; } |
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| 314 | /// Comparison operator |
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| 315 | bool operator<(const ArcIt& e) const { return idx<e.idx; } |
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| 316 | |
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| 317 | private: |
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| 318 | const SimplePath *path; |
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| 319 | int idx; |
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| 320 | }; |
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| 321 | |
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| 322 | /// \brief Length of the path. |
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| 323 | int length() const { return data.size(); } |
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[97] | 324 | /// \brief Return true if the path is empty. |
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[96] | 325 | bool empty() const { return data.empty(); } |
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| 326 | |
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[97] | 327 | /// \brief Reset the path to an empty one. |
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[96] | 328 | void clear() { data.clear(); } |
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| 329 | |
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[97] | 330 | /// \brief The nth arc. |
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[96] | 331 | /// |
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| 332 | /// \pre n is in the [0..length() - 1] range |
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| 333 | const Arc& nth(int n) const { |
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| 334 | return data[n]; |
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| 335 | } |
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| 336 | |
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| 337 | /// \brief Initializes arc iterator to point to the nth arc. |
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| 338 | ArcIt nthIt(int n) const { |
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| 339 | return ArcIt(*this, n); |
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| 340 | } |
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| 341 | |
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[97] | 342 | /// \brief The first arc of the path. |
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[96] | 343 | const Arc& front() const { |
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| 344 | return data.front(); |
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| 345 | } |
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| 346 | |
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[97] | 347 | /// \brief The last arc of the path. |
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[96] | 348 | const Arc& back() const { |
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| 349 | return data.back(); |
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| 350 | } |
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| 351 | |
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| 352 | /// \brief Add a new arc behind the current path. |
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| 353 | void addBack(const Arc& arc) { |
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| 354 | data.push_back(arc); |
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| 355 | } |
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| 356 | |
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| 357 | /// \brief Erase the last arc of the path |
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| 358 | void eraseBack() { |
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| 359 | data.pop_back(); |
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| 360 | } |
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| 361 | |
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| 362 | typedef True BuildTag; |
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| 363 | |
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| 364 | template <typename CPath> |
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| 365 | void build(const CPath& path) { |
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| 366 | int len = path.length(); |
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| 367 | data.resize(len); |
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| 368 | int index = 0; |
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| 369 | for (typename CPath::ArcIt it(path); it != INVALID; ++it) { |
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| 370 | data[index] = it;; |
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| 371 | ++index; |
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| 372 | } |
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| 373 | } |
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| 374 | |
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| 375 | template <typename CPath> |
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| 376 | void buildRev(const CPath& path) { |
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| 377 | int len = path.length(); |
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| 378 | data.resize(len); |
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| 379 | int index = len; |
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| 380 | for (typename CPath::RevArcIt it(path); it != INVALID; ++it) { |
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| 381 | --index; |
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| 382 | data[index] = it;; |
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| 383 | } |
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| 384 | } |
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| 385 | |
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| 386 | protected: |
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| 387 | typedef std::vector<Arc> Container; |
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| 388 | Container data; |
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| 389 | |
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| 390 | }; |
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| 391 | |
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| 392 | /// \brief A structure for representing directed paths in a digraph. |
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| 393 | /// |
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| 394 | /// A structure for representing directed path in a digraph. |
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[157] | 395 | /// \tparam _Digraph The digraph type in which the path is. |
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[96] | 396 | /// |
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| 397 | /// In a sense, the path can be treated as a list of arcs. The |
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| 398 | /// lemon path type stores just this list. As a consequence it |
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| 399 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 400 | /// cannot store the source. |
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| 401 | /// |
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| 402 | /// This implementation is a back and front insertable and erasable |
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| 403 | /// path type. It can be indexed in O(k) time, where k is the rank |
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| 404 | /// of the arc in the path. The length can be computed in O(n) |
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| 405 | /// time. The front and back insertion and erasure is O(1) time |
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| 406 | /// and it can be splited and spliced in O(1) time. |
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| 407 | template <typename _Digraph> |
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| 408 | class ListPath { |
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| 409 | public: |
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| 410 | |
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| 411 | typedef _Digraph Digraph; |
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| 412 | typedef typename Digraph::Arc Arc; |
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| 413 | |
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| 414 | protected: |
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| 415 | |
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[209] | 416 | // the std::list<> is incompatible |
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[96] | 417 | // hard to create invalid iterator |
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| 418 | struct Node { |
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| 419 | Arc arc; |
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| 420 | Node *next, *prev; |
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| 421 | }; |
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| 422 | |
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| 423 | Node *first, *last; |
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| 424 | |
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| 425 | std::allocator<Node> alloc; |
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| 426 | |
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| 427 | public: |
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[209] | 428 | |
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[96] | 429 | /// \brief Default constructor |
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| 430 | /// |
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| 431 | /// Default constructor |
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| 432 | ListPath() : first(0), last(0) {} |
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| 433 | |
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| 434 | /// \brief Template copy constructor |
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| 435 | /// |
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| 436 | /// This path can be initialized with any other path type. It just |
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| 437 | /// makes a copy of the given path. |
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| 438 | template <typename CPath> |
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| 439 | ListPath(const CPath& cpath) : first(0), last(0) { |
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| 440 | copyPath(*this, cpath); |
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| 441 | } |
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| 442 | |
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| 443 | /// \brief Destructor of the path |
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| 444 | /// |
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| 445 | /// Destructor of the path |
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| 446 | ~ListPath() { |
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| 447 | clear(); |
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| 448 | } |
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| 449 | |
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| 450 | /// \brief Template copy assignment |
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| 451 | /// |
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| 452 | /// This path can be initialized with any other path type. It just |
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| 453 | /// makes a copy of the given path. |
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| 454 | template <typename CPath> |
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| 455 | ListPath& operator=(const CPath& cpath) { |
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| 456 | copyPath(*this, cpath); |
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| 457 | return *this; |
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| 458 | } |
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| 459 | |
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| 460 | /// \brief Iterator class to iterate on the arcs of the paths |
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| 461 | /// |
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| 462 | /// This class is used to iterate on the arcs of the paths |
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| 463 | /// |
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| 464 | /// Of course it converts to Digraph::Arc |
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| 465 | class ArcIt { |
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| 466 | friend class ListPath; |
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| 467 | public: |
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| 468 | /// Default constructor |
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| 469 | ArcIt() {} |
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| 470 | /// Invalid constructor |
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| 471 | ArcIt(Invalid) : path(0), node(0) {} |
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| 472 | /// \brief Initializate the constructor to the first arc of path |
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[209] | 473 | ArcIt(const ListPath &_path) |
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[96] | 474 | : path(&_path), node(_path.first) {} |
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| 475 | |
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| 476 | protected: |
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| 477 | |
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[209] | 478 | ArcIt(const ListPath &_path, Node *_node) |
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[96] | 479 | : path(&_path), node(_node) {} |
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| 480 | |
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| 481 | |
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| 482 | public: |
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| 483 | |
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| 484 | ///Conversion to Digraph::Arc |
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| 485 | operator const Arc&() const { |
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| 486 | return node->arc; |
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| 487 | } |
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| 488 | |
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| 489 | /// Next arc |
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[209] | 490 | ArcIt& operator++() { |
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[96] | 491 | node = node->next; |
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[209] | 492 | return *this; |
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[96] | 493 | } |
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| 494 | |
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| 495 | /// Comparison operator |
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| 496 | bool operator==(const ArcIt& e) const { return node==e.node; } |
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| 497 | /// Comparison operator |
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| 498 | bool operator!=(const ArcIt& e) const { return node!=e.node; } |
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| 499 | /// Comparison operator |
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| 500 | bool operator<(const ArcIt& e) const { return node<e.node; } |
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| 501 | |
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| 502 | private: |
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| 503 | const ListPath *path; |
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| 504 | Node *node; |
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| 505 | }; |
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| 506 | |
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[97] | 507 | /// \brief The nth arc. |
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[96] | 508 | /// |
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[97] | 509 | /// This function looks for the nth arc in O(n) time. |
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[96] | 510 | /// \pre n is in the [0..length() - 1] range |
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| 511 | const Arc& nth(int n) const { |
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| 512 | Node *node = first; |
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| 513 | for (int i = 0; i < n; ++i) { |
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| 514 | node = node->next; |
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| 515 | } |
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| 516 | return node->arc; |
---|
| 517 | } |
---|
| 518 | |
---|
| 519 | /// \brief Initializes arc iterator to point to the nth arc. |
---|
| 520 | ArcIt nthIt(int n) const { |
---|
| 521 | Node *node = first; |
---|
| 522 | for (int i = 0; i < n; ++i) { |
---|
| 523 | node = node->next; |
---|
| 524 | } |
---|
| 525 | return ArcIt(*this, node); |
---|
| 526 | } |
---|
| 527 | |
---|
| 528 | /// \brief Length of the path. |
---|
| 529 | int length() const { |
---|
| 530 | int len = 0; |
---|
| 531 | Node *node = first; |
---|
| 532 | while (node != 0) { |
---|
| 533 | node = node->next; |
---|
| 534 | ++len; |
---|
| 535 | } |
---|
| 536 | return len; |
---|
| 537 | } |
---|
| 538 | |
---|
[97] | 539 | /// \brief Return true if the path is empty. |
---|
[96] | 540 | bool empty() const { return first == 0; } |
---|
| 541 | |
---|
[97] | 542 | /// \brief Reset the path to an empty one. |
---|
[96] | 543 | void clear() { |
---|
| 544 | while (first != 0) { |
---|
| 545 | last = first->next; |
---|
| 546 | alloc.destroy(first); |
---|
| 547 | alloc.deallocate(first, 1); |
---|
| 548 | first = last; |
---|
| 549 | } |
---|
| 550 | } |
---|
| 551 | |
---|
[97] | 552 | /// \brief The first arc of the path |
---|
[96] | 553 | const Arc& front() const { |
---|
| 554 | return first->arc; |
---|
| 555 | } |
---|
| 556 | |
---|
| 557 | /// \brief Add a new arc before the current path |
---|
| 558 | void addFront(const Arc& arc) { |
---|
| 559 | Node *node = alloc.allocate(1); |
---|
| 560 | alloc.construct(node, Node()); |
---|
| 561 | node->prev = 0; |
---|
| 562 | node->next = first; |
---|
| 563 | node->arc = arc; |
---|
| 564 | if (first) { |
---|
| 565 | first->prev = node; |
---|
| 566 | first = node; |
---|
| 567 | } else { |
---|
| 568 | first = last = node; |
---|
| 569 | } |
---|
| 570 | } |
---|
| 571 | |
---|
| 572 | /// \brief Erase the first arc of the path |
---|
| 573 | void eraseFront() { |
---|
| 574 | Node *node = first; |
---|
| 575 | first = first->next; |
---|
| 576 | if (first) { |
---|
| 577 | first->prev = 0; |
---|
| 578 | } else { |
---|
| 579 | last = 0; |
---|
| 580 | } |
---|
| 581 | alloc.destroy(node); |
---|
| 582 | alloc.deallocate(node, 1); |
---|
| 583 | } |
---|
| 584 | |
---|
[97] | 585 | /// \brief The last arc of the path. |
---|
[96] | 586 | const Arc& back() const { |
---|
| 587 | return last->arc; |
---|
| 588 | } |
---|
| 589 | |
---|
| 590 | /// \brief Add a new arc behind the current path. |
---|
| 591 | void addBack(const Arc& arc) { |
---|
| 592 | Node *node = alloc.allocate(1); |
---|
| 593 | alloc.construct(node, Node()); |
---|
| 594 | node->next = 0; |
---|
| 595 | node->prev = last; |
---|
| 596 | node->arc = arc; |
---|
| 597 | if (last) { |
---|
| 598 | last->next = node; |
---|
| 599 | last = node; |
---|
| 600 | } else { |
---|
| 601 | last = first = node; |
---|
| 602 | } |
---|
| 603 | } |
---|
| 604 | |
---|
| 605 | /// \brief Erase the last arc of the path |
---|
| 606 | void eraseBack() { |
---|
| 607 | Node *node = last; |
---|
| 608 | last = last->prev; |
---|
| 609 | if (last) { |
---|
| 610 | last->next = 0; |
---|
| 611 | } else { |
---|
| 612 | first = 0; |
---|
| 613 | } |
---|
| 614 | alloc.destroy(node); |
---|
| 615 | alloc.deallocate(node, 1); |
---|
| 616 | } |
---|
| 617 | |
---|
[97] | 618 | /// \brief Splice a path to the back of the current path. |
---|
[96] | 619 | /// |
---|
[97] | 620 | /// It splices \c tpath to the back of the current path and \c |
---|
[96] | 621 | /// tpath becomes empty. The time complexity of this function is |
---|
| 622 | /// O(1). |
---|
| 623 | void spliceBack(ListPath& tpath) { |
---|
| 624 | if (first) { |
---|
| 625 | if (tpath.first) { |
---|
| 626 | last->next = tpath.first; |
---|
| 627 | tpath.first->prev = last; |
---|
| 628 | last = tpath.last; |
---|
| 629 | } |
---|
| 630 | } else { |
---|
| 631 | first = tpath.first; |
---|
| 632 | last = tpath.last; |
---|
| 633 | } |
---|
| 634 | tpath.first = tpath.last = 0; |
---|
| 635 | } |
---|
| 636 | |
---|
[97] | 637 | /// \brief Splice a path to the front of the current path. |
---|
[96] | 638 | /// |
---|
[97] | 639 | /// It splices \c tpath before the current path and \c tpath |
---|
[96] | 640 | /// becomes empty. The time complexity of this function |
---|
| 641 | /// is O(1). |
---|
| 642 | void spliceFront(ListPath& tpath) { |
---|
| 643 | if (first) { |
---|
| 644 | if (tpath.first) { |
---|
| 645 | first->prev = tpath.last; |
---|
| 646 | tpath.last->next = first; |
---|
| 647 | first = tpath.first; |
---|
| 648 | } |
---|
| 649 | } else { |
---|
| 650 | first = tpath.first; |
---|
| 651 | last = tpath.last; |
---|
| 652 | } |
---|
| 653 | tpath.first = tpath.last = 0; |
---|
| 654 | } |
---|
| 655 | |
---|
[97] | 656 | /// \brief Splice a path into the current path. |
---|
[96] | 657 | /// |
---|
| 658 | /// It splices the \c tpath into the current path before the |
---|
| 659 | /// position of \c it iterator and \c tpath becomes empty. The |
---|
[97] | 660 | /// time complexity of this function is O(1). If the \c it is |
---|
| 661 | /// \c INVALID then it will splice behind the current path. |
---|
[96] | 662 | void splice(ArcIt it, ListPath& tpath) { |
---|
| 663 | if (it.node) { |
---|
| 664 | if (tpath.first) { |
---|
| 665 | tpath.first->prev = it.node->prev; |
---|
| 666 | if (it.node->prev) { |
---|
| 667 | it.node->prev->next = tpath.first; |
---|
| 668 | } else { |
---|
| 669 | first = tpath.first; |
---|
| 670 | } |
---|
| 671 | it.node->prev = tpath.last; |
---|
| 672 | tpath.last->next = it.node; |
---|
| 673 | } |
---|
| 674 | } else { |
---|
| 675 | if (first) { |
---|
| 676 | if (tpath.first) { |
---|
| 677 | last->next = tpath.first; |
---|
| 678 | tpath.first->prev = last; |
---|
| 679 | last = tpath.last; |
---|
| 680 | } |
---|
| 681 | } else { |
---|
| 682 | first = tpath.first; |
---|
| 683 | last = tpath.last; |
---|
| 684 | } |
---|
| 685 | } |
---|
| 686 | tpath.first = tpath.last = 0; |
---|
| 687 | } |
---|
| 688 | |
---|
[97] | 689 | /// \brief Split the current path. |
---|
[96] | 690 | /// |
---|
[97] | 691 | /// It splits the current path into two parts. The part before |
---|
| 692 | /// the iterator \c it will remain in the current path and the part |
---|
| 693 | /// starting with |
---|
| 694 | /// \c it will put into \c tpath. If \c tpath have arcs |
---|
| 695 | /// before the operation they are removed first. The time |
---|
| 696 | /// complexity of this function is O(1) plus the the time of emtying |
---|
| 697 | /// \c tpath. If \c it is \c INVALID then it just clears \c tpath |
---|
[96] | 698 | void split(ArcIt it, ListPath& tpath) { |
---|
| 699 | tpath.clear(); |
---|
| 700 | if (it.node) { |
---|
| 701 | tpath.first = it.node; |
---|
| 702 | tpath.last = last; |
---|
| 703 | if (it.node->prev) { |
---|
| 704 | last = it.node->prev; |
---|
| 705 | last->next = 0; |
---|
| 706 | } else { |
---|
| 707 | first = last = 0; |
---|
| 708 | } |
---|
| 709 | it.node->prev = 0; |
---|
| 710 | } |
---|
| 711 | } |
---|
| 712 | |
---|
| 713 | |
---|
| 714 | typedef True BuildTag; |
---|
| 715 | |
---|
| 716 | template <typename CPath> |
---|
| 717 | void build(const CPath& path) { |
---|
| 718 | for (typename CPath::ArcIt it(path); it != INVALID; ++it) { |
---|
| 719 | addBack(it); |
---|
| 720 | } |
---|
| 721 | } |
---|
| 722 | |
---|
| 723 | template <typename CPath> |
---|
| 724 | void buildRev(const CPath& path) { |
---|
| 725 | for (typename CPath::RevArcIt it(path); it != INVALID; ++it) { |
---|
| 726 | addFront(it); |
---|
| 727 | } |
---|
| 728 | } |
---|
| 729 | |
---|
| 730 | }; |
---|
| 731 | |
---|
| 732 | /// \brief A structure for representing directed paths in a digraph. |
---|
| 733 | /// |
---|
| 734 | /// A structure for representing directed path in a digraph. |
---|
[157] | 735 | /// \tparam _Digraph The digraph type in which the path is. |
---|
[96] | 736 | /// |
---|
| 737 | /// In a sense, the path can be treated as a list of arcs. The |
---|
| 738 | /// lemon path type stores just this list. As a consequence it |
---|
[97] | 739 | /// cannot enumerate the nodes in the path and the source node of |
---|
| 740 | /// a zero length path is undefined. |
---|
[96] | 741 | /// |
---|
[97] | 742 | /// This implementation is completly static, i.e. it can be copy constucted |
---|
| 743 | /// or copy assigned from another path, but otherwise it cannot be |
---|
| 744 | /// modified. |
---|
| 745 | /// |
---|
| 746 | /// Being the the most memory efficient path type in LEMON, |
---|
| 747 | /// it is intented to be |
---|
| 748 | /// used when you want to store a large number of paths. |
---|
[96] | 749 | template <typename _Digraph> |
---|
| 750 | class StaticPath { |
---|
| 751 | public: |
---|
| 752 | |
---|
| 753 | typedef _Digraph Digraph; |
---|
| 754 | typedef typename Digraph::Arc Arc; |
---|
| 755 | |
---|
| 756 | /// \brief Default constructor |
---|
| 757 | /// |
---|
| 758 | /// Default constructor |
---|
| 759 | StaticPath() : len(0), arcs(0) {} |
---|
[209] | 760 | |
---|
[96] | 761 | /// \brief Template copy constructor |
---|
| 762 | /// |
---|
[97] | 763 | /// This path can be initialized from any other path type. |
---|
[96] | 764 | template <typename CPath> |
---|
| 765 | StaticPath(const CPath& cpath) : arcs(0) { |
---|
| 766 | copyPath(*this, cpath); |
---|
| 767 | } |
---|
| 768 | |
---|
| 769 | /// \brief Destructor of the path |
---|
| 770 | /// |
---|
| 771 | /// Destructor of the path |
---|
| 772 | ~StaticPath() { |
---|
| 773 | if (arcs) delete[] arcs; |
---|
| 774 | } |
---|
| 775 | |
---|
| 776 | /// \brief Template copy assignment |
---|
| 777 | /// |
---|
[97] | 778 | /// This path can be made equal to any other path type. It simply |
---|
[96] | 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 arcs of the paths |
---|
| 787 | /// |
---|
| 788 | /// This class is used to iterate on the arcs of the paths |
---|
| 789 | /// |
---|
| 790 | /// Of course it converts to Digraph::Arc |
---|
| 791 | class ArcIt { |
---|
| 792 | friend class StaticPath; |
---|
| 793 | public: |
---|
| 794 | /// Default constructor |
---|
| 795 | ArcIt() {} |
---|
| 796 | /// Invalid constructor |
---|
| 797 | ArcIt(Invalid) : path(0), idx(-1) {} |
---|
| 798 | /// Initializate the constructor to the first arc of path |
---|
[209] | 799 | ArcIt(const StaticPath &_path) |
---|
[96] | 800 | : path(&_path), idx(_path.empty() ? -1 : 0) {} |
---|
| 801 | |
---|
| 802 | private: |
---|
| 803 | |
---|
| 804 | /// Constructor with starting point |
---|
[209] | 805 | ArcIt(const StaticPath &_path, int _idx) |
---|
[96] | 806 | : idx(_idx), path(&_path) {} |
---|
| 807 | |
---|
| 808 | public: |
---|
| 809 | |
---|
| 810 | ///Conversion to Digraph::Arc |
---|
| 811 | operator const Arc&() const { |
---|
| 812 | return path->nth(idx); |
---|
| 813 | } |
---|
| 814 | |
---|
| 815 | /// Next arc |
---|
[209] | 816 | ArcIt& operator++() { |
---|
[96] | 817 | ++idx; |
---|
[209] | 818 | if (idx >= path->length()) idx = -1; |
---|
| 819 | return *this; |
---|
[96] | 820 | } |
---|
| 821 | |
---|
| 822 | /// Comparison operator |
---|
| 823 | bool operator==(const ArcIt& e) const { return idx==e.idx; } |
---|
| 824 | /// Comparison operator |
---|
| 825 | bool operator!=(const ArcIt& e) const { return idx!=e.idx; } |
---|
| 826 | /// Comparison operator |
---|
| 827 | bool operator<(const ArcIt& e) const { return idx<e.idx; } |
---|
| 828 | |
---|
| 829 | private: |
---|
| 830 | const StaticPath *path; |
---|
| 831 | int idx; |
---|
| 832 | }; |
---|
| 833 | |
---|
[97] | 834 | /// \brief The nth arc. |
---|
[96] | 835 | /// |
---|
| 836 | /// \pre n is in the [0..length() - 1] range |
---|
| 837 | const Arc& nth(int n) const { |
---|
| 838 | return arcs[n]; |
---|
| 839 | } |
---|
| 840 | |
---|
[97] | 841 | /// \brief The arc iterator pointing to the nth arc. |
---|
[96] | 842 | ArcIt nthIt(int n) const { |
---|
| 843 | return ArcIt(*this, n); |
---|
| 844 | } |
---|
| 845 | |
---|
[97] | 846 | /// \brief The length of the path. |
---|
[96] | 847 | int length() const { return len; } |
---|
| 848 | |
---|
[97] | 849 | /// \brief Return true when the path is empty. |
---|
[96] | 850 | int empty() const { return len == 0; } |
---|
| 851 | |
---|
[313] | 852 | /// \brief Erase all arcs in the digraph. |
---|
[96] | 853 | void clear() { |
---|
| 854 | len = 0; |
---|
| 855 | if (arcs) delete[] arcs; |
---|
| 856 | arcs = 0; |
---|
| 857 | } |
---|
| 858 | |
---|
[97] | 859 | /// \brief The first arc of the path. |
---|
[96] | 860 | const Arc& front() const { |
---|
| 861 | return arcs[0]; |
---|
| 862 | } |
---|
| 863 | |
---|
[97] | 864 | /// \brief The last arc of the path. |
---|
[96] | 865 | const Arc& back() const { |
---|
| 866 | return arcs[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 | arcs = new Arc[len]; |
---|
| 876 | int index = 0; |
---|
| 877 | for (typename CPath::ArcIt it(path); it != INVALID; ++it) { |
---|
| 878 | arcs[index] = it; |
---|
| 879 | ++index; |
---|
| 880 | } |
---|
| 881 | } |
---|
| 882 | |
---|
| 883 | template <typename CPath> |
---|
| 884 | void buildRev(const CPath& path) { |
---|
| 885 | len = path.length(); |
---|
| 886 | arcs = new Arc[len]; |
---|
| 887 | int index = len; |
---|
| 888 | for (typename CPath::RevArcIt it(path); it != INVALID; ++it) { |
---|
| 889 | --index; |
---|
| 890 | arcs[index] = it; |
---|
| 891 | } |
---|
| 892 | } |
---|
| 893 | |
---|
| 894 | private: |
---|
| 895 | int len; |
---|
| 896 | Arc* arcs; |
---|
| 897 | }; |
---|
| 898 | |
---|
[98] | 899 | /////////////////////////////////////////////////////////////////////// |
---|
| 900 | // Additional utilities |
---|
| 901 | /////////////////////////////////////////////////////////////////////// |
---|
| 902 | |
---|
| 903 | namespace _path_bits { |
---|
| 904 | |
---|
| 905 | template <typename Path, typename Enable = void> |
---|
[144] | 906 | struct RevPathTagIndicator { |
---|
[98] | 907 | static const bool value = false; |
---|
| 908 | }; |
---|
| 909 | |
---|
[144] | 910 | template <typename Path> |
---|
| 911 | struct RevPathTagIndicator< |
---|
[209] | 912 | Path, |
---|
[144] | 913 | typename enable_if<typename Path::RevPathTag, void>::type |
---|
| 914 | > { |
---|
| 915 | static const bool value = true; |
---|
| 916 | }; |
---|
| 917 | |
---|
| 918 | template <typename Path, typename Enable = void> |
---|
| 919 | struct BuildTagIndicator { |
---|
| 920 | static const bool value = false; |
---|
| 921 | }; |
---|
| 922 | |
---|
| 923 | template <typename Path> |
---|
| 924 | struct BuildTagIndicator< |
---|
[209] | 925 | Path, |
---|
[144] | 926 | typename enable_if<typename Path::BuildTag, void>::type |
---|
[98] | 927 | > { |
---|
| 928 | static const bool value = true; |
---|
| 929 | }; |
---|
| 930 | |
---|
| 931 | template <typename Target, typename Source, |
---|
[209] | 932 | bool buildEnable = BuildTagIndicator<Target>::value, |
---|
| 933 | bool revEnable = RevPathTagIndicator<Source>::value> |
---|
[98] | 934 | struct PathCopySelector { |
---|
| 935 | static void copy(Target& target, const Source& source) { |
---|
| 936 | target.clear(); |
---|
| 937 | for (typename Source::ArcIt it(source); it != INVALID; ++it) { |
---|
| 938 | target.addBack(it); |
---|
| 939 | } |
---|
| 940 | } |
---|
| 941 | }; |
---|
| 942 | |
---|
[144] | 943 | template <typename Target, typename Source> |
---|
| 944 | struct PathCopySelector<Target, Source, false, true> { |
---|
[98] | 945 | static void copy(Target& target, const Source& source) { |
---|
| 946 | target.clear(); |
---|
| 947 | for (typename Source::RevArcIt it(source); it != INVALID; ++it) { |
---|
| 948 | target.addFront(it); |
---|
| 949 | } |
---|
| 950 | } |
---|
| 951 | }; |
---|
| 952 | |
---|
[144] | 953 | template <typename Target, typename Source> |
---|
| 954 | struct PathCopySelector<Target, Source, true, false> { |
---|
[98] | 955 | static void copy(Target& target, const Source& source) { |
---|
| 956 | target.clear(); |
---|
| 957 | target.build(source); |
---|
| 958 | } |
---|
| 959 | }; |
---|
| 960 | |
---|
| 961 | template <typename Target, typename Source> |
---|
[144] | 962 | struct PathCopySelector<Target, Source, true, true> { |
---|
[98] | 963 | static void copy(Target& target, const Source& source) { |
---|
| 964 | target.clear(); |
---|
| 965 | target.buildRev(source); |
---|
| 966 | } |
---|
| 967 | }; |
---|
| 968 | |
---|
| 969 | } |
---|
| 970 | |
---|
| 971 | |
---|
| 972 | /// \brief Make a copy of a path. |
---|
| 973 | /// |
---|
| 974 | /// This function makes a copy of a path. |
---|
| 975 | template <typename Target, typename Source> |
---|
| 976 | void copyPath(Target& target, const Source& source) { |
---|
| 977 | checkConcept<concepts::PathDumper<typename Source::Digraph>, Source>(); |
---|
| 978 | _path_bits::PathCopySelector<Target, Source>::copy(target, source); |
---|
| 979 | } |
---|
| 980 | |
---|
| 981 | /// \brief Check the consistency of a path. |
---|
| 982 | /// |
---|
| 983 | /// This function checks that the target of each arc is the same |
---|
[209] | 984 | /// as the source of the next one. |
---|
| 985 | /// |
---|
[98] | 986 | template <typename Digraph, typename Path> |
---|
| 987 | bool checkPath(const Digraph& digraph, const Path& path) { |
---|
| 988 | typename Path::ArcIt it(path); |
---|
| 989 | if (it == INVALID) return true; |
---|
| 990 | typename Digraph::Node node = digraph.target(it); |
---|
| 991 | ++it; |
---|
| 992 | while (it != INVALID) { |
---|
| 993 | if (digraph.source(it) != node) return false; |
---|
| 994 | node = digraph.target(it); |
---|
| 995 | ++it; |
---|
| 996 | } |
---|
| 997 | return true; |
---|
| 998 | } |
---|
| 999 | |
---|
| 1000 | /// \brief The source of a path |
---|
| 1001 | /// |
---|
| 1002 | /// This function returns the source of the given path. |
---|
| 1003 | template <typename Digraph, typename Path> |
---|
| 1004 | typename Digraph::Node pathSource(const Digraph& digraph, const Path& path) { |
---|
| 1005 | return digraph.source(path.front()); |
---|
| 1006 | } |
---|
| 1007 | |
---|
| 1008 | /// \brief The target of a path |
---|
| 1009 | /// |
---|
| 1010 | /// This function returns the target of the given path. |
---|
| 1011 | template <typename Digraph, typename Path> |
---|
| 1012 | typename Digraph::Node pathTarget(const Digraph& digraph, const Path& path) { |
---|
| 1013 | return digraph.target(path.back()); |
---|
| 1014 | } |
---|
| 1015 | |
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| 1016 | /// \brief Class which helps to iterate through the nodes of a path |
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| 1017 | /// |
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| 1018 | /// In a sense, the path can be treated as a list of arcs. The |
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| 1019 | /// lemon path type stores only this list. As a consequence, it |
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| 1020 | /// cannot enumerate the nodes in the path and the zero length paths |
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| 1021 | /// cannot have a source node. |
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| 1022 | /// |
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| 1023 | /// This class implements the node iterator of a path structure. To |
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| 1024 | /// provide this feature, the underlying digraph should be passed to |
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| 1025 | /// the constructor of the iterator. |
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| 1026 | template <typename Path> |
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| 1027 | class PathNodeIt { |
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| 1028 | private: |
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| 1029 | const typename Path::Digraph *_digraph; |
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| 1030 | typename Path::ArcIt _it; |
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| 1031 | typename Path::Digraph::Node _nd; |
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| 1032 | |
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| 1033 | public: |
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| 1034 | |
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| 1035 | typedef typename Path::Digraph Digraph; |
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| 1036 | typedef typename Digraph::Node Node; |
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[209] | 1037 | |
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[98] | 1038 | /// Default constructor |
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| 1039 | PathNodeIt() {} |
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| 1040 | /// Invalid constructor |
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[209] | 1041 | PathNodeIt(Invalid) |
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[98] | 1042 | : _digraph(0), _it(INVALID), _nd(INVALID) {} |
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| 1043 | /// Constructor |
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[209] | 1044 | PathNodeIt(const Digraph& digraph, const Path& path) |
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[98] | 1045 | : _digraph(&digraph), _it(path) { |
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| 1046 | _nd = (_it != INVALID ? _digraph->source(_it) : INVALID); |
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| 1047 | } |
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| 1048 | /// Constructor |
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[209] | 1049 | PathNodeIt(const Digraph& digraph, const Path& path, const Node& src) |
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[98] | 1050 | : _digraph(&digraph), _it(path), _nd(src) {} |
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| 1051 | |
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| 1052 | ///Conversion to Digraph::Node |
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| 1053 | operator Node() const { |
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| 1054 | return _nd; |
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| 1055 | } |
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| 1056 | |
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| 1057 | /// Next node |
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| 1058 | PathNodeIt& operator++() { |
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| 1059 | if (_it == INVALID) _nd = INVALID; |
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| 1060 | else { |
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[209] | 1061 | _nd = _digraph->target(_it); |
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| 1062 | ++_it; |
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[98] | 1063 | } |
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| 1064 | return *this; |
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| 1065 | } |
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| 1066 | |
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| 1067 | /// Comparison operator |
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[209] | 1068 | bool operator==(const PathNodeIt& n) const { |
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| 1069 | return _it == n._it && _nd == n._nd; |
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[98] | 1070 | } |
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| 1071 | /// Comparison operator |
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[209] | 1072 | bool operator!=(const PathNodeIt& n) const { |
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| 1073 | return _it != n._it || _nd != n._nd; |
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[98] | 1074 | } |
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| 1075 | /// Comparison operator |
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[209] | 1076 | bool operator<(const PathNodeIt& n) const { |
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[98] | 1077 | return (_it < n._it && _nd != INVALID); |
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| 1078 | } |
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[209] | 1079 | |
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[98] | 1080 | }; |
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[209] | 1081 | |
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[96] | 1082 | ///@} |
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| 1083 | |
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| 1084 | } // namespace lemon |
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| 1085 | |
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| 1086 | #endif // LEMON_PATH_H |
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