GreedyTsp implements the greedy heuristic for solving symmetric TSP.
This algorithm is quite similar to the nearest neighbor heuristic, but it maintains a set of disjoint paths. At each step, the shortest possible edge is added to these paths as long as it does not create a cycle of less than n edges and it does not increase the degree of any node above two.
This method runs in O(n2) time. It quickly finds a relatively short tour for most TSP instances, but it could also yield a really bad (or even the worst) solution in special cases.
| CM | Type of the cost map. |
#include <lemon/greedy_tsp.h>
Public Types | |
| typedef CM | CostMap |
| Type of the cost map. | |
| typedef CM::Value | Cost |
| Type of the edge costs. | |
Public Member Functions | |
| GreedyTsp (const FullGraph &gr, const CostMap &cost) | |
| Constructor. More... | |
Execution Control | |
| Cost | run () |
| Runs the algorithm. More... | |
Query Functions | |
| Cost | tourCost () const |
| The total cost of the found tour. More... | |
| const std::vector< Node > & | tourNodes () const |
| Returns a const reference to the node sequence of the found tour. More... | |
| template<typename Iterator > | |
| void | tourNodes (Iterator out) const |
| Gives back the node sequence of the found tour. More... | |
| template<typename Path > | |
| void | tour (Path &path) const |
| Gives back the found tour as a path. More... | |
Constructor.
| gr | The full graph the algorithm runs on. |
| cost | The cost map. |
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This function runs the algorithm.
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This function returns the total cost of the found tour.
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This function returns a const reference to a vector that stores the node sequence of the found tour.
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This function copies the node sequence of the found tour into an STL container through the given output iterator. The value_type of the container must be FullGraph::Node. For example,
or
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This function copies the found tour as a list of arcs/edges into the given path structure.
1.8.5