[1031] | 1 | #ifndef LEMON_INSERTION_TSP_H |
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| 2 | #define LEMON_INSERTION_TSP_H |
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| 3 | |
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| 4 | #include <lemon/full_graph.h> |
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| 5 | #include <lemon/path.h> |
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| 6 | #include <lemon/maps.h> |
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| 7 | #include <lemon/random.h> |
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| 8 | #include <vector> |
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| 9 | |
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| 10 | namespace lemon { |
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| 11 | |
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| 12 | namespace insertion_tsp_helper { |
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| 13 | |
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| 14 | template <class L> |
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| 15 | L vectorConvert(const std::vector<FullGraph::Node> &_path) { |
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| 16 | return L(_path.begin(), _path.end()); |
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| 17 | }; |
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| 18 | |
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| 19 | template <> |
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| 20 | std::vector<FullGraph::Node> vectorConvert( |
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| 21 | const std::vector<FullGraph::Node> &_path) { |
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| 22 | return _path; |
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| 23 | }; |
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| 24 | |
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| 25 | }; |
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| 26 | |
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| 27 | template <typename CM> |
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| 28 | class InsertionTsp { |
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| 29 | private: |
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| 30 | GRAPH_TYPEDEFS(FullGraph); |
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| 31 | |
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| 32 | public: |
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| 33 | typedef CM CostMap; |
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| 34 | typedef typename CM::Value Cost; |
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| 35 | |
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| 36 | InsertionTsp(const FullGraph &gr, const CostMap &cost) : |
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| 37 | _gr(gr), _cost(cost) {} |
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| 38 | |
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| 39 | enum InsertionMethod { |
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| 40 | INSERT_NEAREST, |
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| 41 | INSERT_FARTHEST, |
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| 42 | INSERT_CHEAPEST, |
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| 43 | INSERT_RANDOM |
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| 44 | }; |
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| 45 | |
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| 46 | Cost run(InsertionMethod method = INSERT_FARTHEST) { |
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| 47 | switch (method) { |
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| 48 | case INSERT_NEAREST: |
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| 49 | start<InitTour<true>, NearestSelection, DefaultInsert>(); |
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| 50 | break; |
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| 51 | case INSERT_FARTHEST: |
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| 52 | start<InitTour<false>, FarthestSelection, DefaultInsert>(); |
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| 53 | break; |
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| 54 | case INSERT_CHEAPEST: |
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| 55 | start<InitTour<true>, CheapestSelection, CheapestInsert>(); |
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| 56 | break; |
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| 57 | case INSERT_RANDOM: |
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| 58 | start<InitTour<true>, RandomSelection, DefaultInsert>(); |
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| 59 | break; |
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| 60 | } |
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| 61 | return sum; |
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| 62 | } |
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| 63 | |
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| 64 | template <typename L> |
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| 65 | void tourNodes(L &container) { |
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| 66 | container(insertion_tsp_helper::vectorConvert<L>(nodesPath)); |
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| 67 | } |
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| 68 | |
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| 69 | template <template <typename> class L> |
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| 70 | L<Node> tourNodes() { |
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| 71 | return insertion_tsp_helper::vectorConvert<L<Node> >(nodesPath); |
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| 72 | } |
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| 73 | |
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| 74 | const std::vector<Node>& tourNodes() { |
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| 75 | return nodesPath; |
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| 76 | } |
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| 77 | |
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| 78 | Path<FullGraph> tour() { |
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| 79 | Path<FullGraph> p; |
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| 80 | if (nodesPath.size()<2) |
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| 81 | return p; |
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| 82 | |
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| 83 | for (unsigned int i=0; i<nodesPath.size()-1; ++i) |
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| 84 | p.addBack(_gr.arc(nodesPath[i], nodesPath[i+1])); |
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| 85 | |
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| 86 | p.addBack(_gr.arc(nodesPath.back(), nodesPath.front())); |
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| 87 | return p; |
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| 88 | } |
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| 89 | |
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| 90 | Cost tourCost() { |
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| 91 | return sum; |
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| 92 | } |
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| 93 | |
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| 94 | |
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| 95 | private: |
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| 96 | |
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| 97 | template <bool MIN> |
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| 98 | class InitTour { |
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| 99 | public: |
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| 100 | InitTour(const FullGraph &gr, const CostMap &cost, |
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| 101 | std::vector<Node> &used, std::vector<Node> ¬used, |
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| 102 | Cost &fullcost) : |
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| 103 | _gr(gr), _cost(cost), _used(used), _notused(notused), |
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| 104 | _fullcost(fullcost) {} |
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| 105 | |
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| 106 | std::vector<Node> init() const { |
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| 107 | Edge min = (MIN) ? mapMin(_gr, _cost) : mapMax(_gr, _cost); |
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| 108 | std::vector<Node> path; |
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| 109 | path.push_back(_gr.u(min)); |
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| 110 | path.push_back(_gr.v(min)); |
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| 111 | |
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| 112 | _used.clear(); |
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| 113 | _notused.clear(); |
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| 114 | for (NodeIt n(_gr); n!=INVALID; ++n) { |
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| 115 | if (n != _gr.u(min) && n != _gr.v(min)) { |
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| 116 | _notused.push_back(n); |
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| 117 | } |
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| 118 | } |
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| 119 | _used.push_back(_gr.u(min)); |
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| 120 | _used.push_back(_gr.v(min)); |
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| 121 | |
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| 122 | _fullcost = _cost[min]*2; |
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| 123 | return path; |
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| 124 | } |
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| 125 | |
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| 126 | private: |
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| 127 | const FullGraph &_gr; |
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| 128 | const CostMap &_cost; |
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| 129 | std::vector<Node> &_used; |
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| 130 | std::vector<Node> &_notused; |
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| 131 | Cost &_fullcost; |
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| 132 | }; |
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| 133 | |
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| 134 | class NearestSelection { |
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| 135 | public: |
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| 136 | NearestSelection(const FullGraph &gr, const CostMap &cost, |
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| 137 | std::vector<Node> &used, std::vector<Node> ¬used) : |
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| 138 | _gr(gr), _cost(cost), _used(used), _notused(notused) {} |
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| 139 | |
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| 140 | Node select() const { |
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| 141 | |
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| 142 | Cost insert_val = |
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| 143 | std::numeric_limits<Cost>::max(); |
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| 144 | int insert_node = -1; |
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| 145 | |
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| 146 | for (unsigned int i=0; i<_notused.size(); ++i) { |
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| 147 | Cost min_val = _cost[_gr.edge(_notused[i], _used[0])]; |
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| 148 | int min_node = 0; |
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| 149 | |
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| 150 | for (unsigned int j=1; j<_used.size(); ++j) { |
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| 151 | if (min_val > _cost[_gr.edge(_notused[i], _used[j])]) { |
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| 152 | min_val = _cost[_gr.edge(_notused[i], _used[j])]; |
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| 153 | min_node = j; |
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| 154 | } |
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| 155 | } |
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| 156 | |
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| 157 | if (insert_val > min_val) { |
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| 158 | insert_val = min_val; |
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| 159 | insert_node = i; |
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| 160 | } |
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| 161 | } |
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| 162 | |
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| 163 | Node n = _notused[insert_node]; |
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| 164 | _notused.erase(_notused.begin()+insert_node); |
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| 165 | |
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| 166 | return n; |
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| 167 | } |
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| 168 | |
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| 169 | private: |
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| 170 | const FullGraph &_gr; |
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| 171 | const CostMap &_cost; |
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| 172 | std::vector<Node> &_used; |
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| 173 | std::vector<Node> &_notused; |
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| 174 | }; |
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| 175 | |
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| 176 | class FarthestSelection { |
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| 177 | public: |
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| 178 | FarthestSelection(const FullGraph &gr, const CostMap &cost, |
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| 179 | std::vector<Node> &used, std::vector<Node> ¬used) : |
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| 180 | _gr(gr), _cost(cost), _used(used), _notused(notused) {} |
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| 181 | |
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| 182 | Node select() const { |
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| 183 | |
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| 184 | Cost insert_val = |
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| 185 | std::numeric_limits<Cost>::min(); |
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| 186 | int insert_node = -1; |
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| 187 | |
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| 188 | for (unsigned int i=0; i<_notused.size(); ++i) { |
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| 189 | Cost min_val = _cost[_gr.edge(_notused[i], _used[0])]; |
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| 190 | int min_node = 0; |
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| 191 | |
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| 192 | for (unsigned int j=1; j<_used.size(); ++j) { |
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| 193 | if (min_val > _cost[_gr.edge(_notused[i], _used[j])]) { |
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| 194 | min_val = _cost[_gr.edge(_notused[i], _used[j])]; |
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| 195 | min_node = j; |
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| 196 | } |
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| 197 | } |
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| 198 | |
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| 199 | if (insert_val < min_val || insert_node == -1) { |
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| 200 | insert_val = min_val; |
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| 201 | insert_node = i; |
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| 202 | } |
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| 203 | } |
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| 204 | |
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| 205 | Node n = _notused[insert_node]; |
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| 206 | _notused.erase(_notused.begin()+insert_node); |
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| 207 | |
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| 208 | return n; |
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| 209 | } |
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| 210 | |
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| 211 | private: |
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| 212 | const FullGraph &_gr; |
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| 213 | const CostMap &_cost; |
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| 214 | std::vector<Node> &_used; |
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| 215 | std::vector<Node> &_notused; |
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| 216 | }; |
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| 217 | |
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| 218 | |
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| 219 | class CheapestSelection { |
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| 220 | private: |
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| 221 | Cost costDiff(Node u, Node v, Node w) const { |
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| 222 | return |
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| 223 | _cost[_gr.edge(u, w)] + |
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| 224 | _cost[_gr.edge(v, w)] - |
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| 225 | _cost[_gr.edge(u, v)]; |
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| 226 | } |
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| 227 | |
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| 228 | public: |
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| 229 | CheapestSelection(const FullGraph &gr, const CostMap &cost, |
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| 230 | std::vector<Node> &used, std::vector<Node> ¬used) : |
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| 231 | _gr(gr), _cost(cost), _used(used), _notused(notused) {} |
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| 232 | |
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| 233 | Cost select() const { |
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| 234 | int insert_notused = -1; |
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| 235 | int best_insert_index = -1; |
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| 236 | Cost insert_val = |
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| 237 | std::numeric_limits<Cost>::max(); |
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| 238 | |
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| 239 | for (unsigned int i=0; i<_notused.size(); ++i) { |
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| 240 | int min = i; |
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| 241 | int best_insert_tmp = 0; |
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| 242 | Cost min_val = |
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| 243 | costDiff(_used.front(), _used.back(), _notused[i]); |
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| 244 | |
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| 245 | for (unsigned int j=1; j<_used.size(); ++j) { |
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| 246 | Cost tmp = |
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| 247 | costDiff(_used[j-1], _used[j], _notused[i]); |
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| 248 | |
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| 249 | if (min_val > tmp) { |
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| 250 | min = i; |
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| 251 | min_val = tmp; |
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| 252 | best_insert_tmp = j; |
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| 253 | } |
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| 254 | } |
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| 255 | |
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| 256 | if (insert_val > min_val) { |
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| 257 | insert_notused = min; |
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| 258 | insert_val = min_val; |
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| 259 | best_insert_index = best_insert_tmp; |
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| 260 | } |
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| 261 | } |
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| 262 | |
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| 263 | _used.insert(_used.begin()+best_insert_index, _notused[insert_notused]); |
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| 264 | _notused.erase(_notused.begin()+insert_notused); |
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| 265 | |
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| 266 | return insert_val; |
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| 267 | } |
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| 268 | |
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| 269 | private: |
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| 270 | const FullGraph &_gr; |
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| 271 | const CostMap &_cost; |
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| 272 | std::vector<Node> &_used; |
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| 273 | std::vector<Node> &_notused; |
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| 274 | }; |
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| 275 | |
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| 276 | class RandomSelection { |
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| 277 | public: |
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| 278 | RandomSelection(const FullGraph &, const CostMap &, |
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| 279 | std::vector<Node> &, std::vector<Node> ¬used) : |
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| 280 | _notused(notused) { |
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| 281 | rnd.seedFromTime(); |
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| 282 | } |
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| 283 | |
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| 284 | Node select() const { |
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| 285 | const int index = rnd[_notused.size()]; |
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| 286 | Node n = _notused[index]; |
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| 287 | _notused.erase(_notused.begin()+index); |
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| 288 | return n; |
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| 289 | } |
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| 290 | private: |
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| 291 | std::vector<Node> &_notused; |
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| 292 | }; |
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| 293 | |
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| 294 | |
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| 295 | class DefaultInsert { |
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| 296 | private: |
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| 297 | Cost costDiff(Node u, Node v, Node w) const { |
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| 298 | return |
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| 299 | _cost[_gr.edge(u, w)] + |
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| 300 | _cost[_gr.edge(v, w)] - |
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| 301 | _cost[_gr.edge(u, v)]; |
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| 302 | } |
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| 303 | |
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| 304 | public: |
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| 305 | DefaultInsert(const FullGraph &gr, const CostMap &cost, |
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| 306 | std::vector<Node> &path, Cost &fullcost) : |
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| 307 | _gr(gr), _cost(cost), _path(path), _fullcost(fullcost) {} |
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| 308 | |
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| 309 | void insert(Node n) const { |
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| 310 | int min = 0; |
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| 311 | Cost min_val = |
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| 312 | costDiff(_path.front(), _path.back(), n); |
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| 313 | |
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| 314 | for (unsigned int i=1; i<_path.size(); ++i) { |
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| 315 | Cost tmp = costDiff(_path[i-1], _path[i], n); |
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| 316 | if (tmp < min_val) { |
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| 317 | min = i; |
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| 318 | min_val = tmp; |
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| 319 | } |
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| 320 | } |
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| 321 | |
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| 322 | _path.insert(_path.begin()+min, n); |
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| 323 | _fullcost += min_val; |
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| 324 | } |
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| 325 | |
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| 326 | private: |
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| 327 | const FullGraph &_gr; |
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| 328 | const CostMap &_cost; |
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| 329 | std::vector<Node> &_path; |
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| 330 | Cost &_fullcost; |
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| 331 | }; |
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| 332 | |
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| 333 | class CheapestInsert { |
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| 334 | TEMPLATE_GRAPH_TYPEDEFS(FullGraph); |
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| 335 | public: |
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| 336 | CheapestInsert(const FullGraph &, const CostMap &, |
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| 337 | std::vector<Node> &, Cost &fullcost) : |
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| 338 | _fullcost(fullcost) {} |
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| 339 | |
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| 340 | void insert(Cost diff) const { |
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| 341 | _fullcost += diff; |
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| 342 | } |
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| 343 | |
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| 344 | private: |
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| 345 | Cost &_fullcost; |
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| 346 | }; |
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| 347 | |
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| 348 | |
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| 349 | template <class InitFunctor, class SelectionFunctor, class InsertFunctor> |
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| 350 | void start() { |
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| 351 | InitFunctor init(_gr, _cost, nodesPath, notused, sum); |
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| 352 | SelectionFunctor selectNode(_gr, _cost, nodesPath, notused); |
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| 353 | InsertFunctor insertNode(_gr, _cost, nodesPath, sum); |
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| 354 | |
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| 355 | nodesPath = init.init(); |
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| 356 | |
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| 357 | for (int i=0; i<_gr.nodeNum()-2; ++i) { |
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| 358 | insertNode.insert(selectNode.select()); |
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| 359 | } |
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| 360 | |
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| 361 | sum = _cost[ _gr.edge(nodesPath.front(), nodesPath.back()) ]; |
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| 362 | for (unsigned int i=0; i<nodesPath.size()-1; ++i) |
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| 363 | sum += _cost[ _gr.edge(nodesPath[i], nodesPath[i+1]) ]; |
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| 364 | } |
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| 365 | |
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| 366 | const FullGraph &_gr; |
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| 367 | const CostMap &_cost; |
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| 368 | std::vector<Node> notused; |
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| 369 | std::vector<Node> nodesPath; |
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| 370 | Cost sum; |
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| 371 | }; |
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| 372 | |
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| 373 | }; // namespace lemon |
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| 374 | |
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| 375 | #endif |
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