Definition at line 453 of file hamiltonian_path.h.
Public Types | |
| typedef uint32 | Integer |
| HamiltonianPathSolver computes a minimum Hamiltonian path starting at node 0 over a graph defined by a cost matrix. More... | |
| typedef Set< Integer > | NodeSet |
Public Member Functions | |
| HamiltonianPathSolver (CostFunction cost) | |
| HamiltonianPathSolver (int num_nodes, CostFunction cost) | |
| void | ChangeCostMatrix (CostFunction cost) |
| Replaces the cost matrix while avoiding re-allocating memory. More... | |
| void | ChangeCostMatrix (int num_nodes, CostFunction cost) |
| CostType | HamiltonianCost (int end_node) |
| Returns the cost of the Hamiltonian path from 0 to end_node. More... | |
| std::vector< int > | HamiltonianPath (int end_node) |
| Returns the shortest Hamiltonian path from 0 to end_node. More... | |
| int | BestHamiltonianPathEndNode () |
| Returns the end-node that yields the shortest Hamiltonian path of all shortest Hamiltonian path from 0 to end-node (end-node != 0). More... | |
| void | HamiltonianPath (std::vector< PathNodeIndex > *path) |
| CostType | TravelingSalesmanCost () |
| Returns the cost of the TSP tour. More... | |
| std::vector< int > | TravelingSalesmanPath () |
| Returns the TSP tour in the vector pointed to by the argument. More... | |
| void | TravelingSalesmanPath (std::vector< PathNodeIndex > *path) |
| bool | IsRobust () |
| Returns true if there won't be precision issues. More... | |
| bool | VerifiesTriangleInequality () |
| Returns true if the cost matrix verifies the triangle inequality. More... | |
| typedef uint32 operations_research::HamiltonianPathSolver< CostType, CostFunction >::Integer |
HamiltonianPathSolver computes a minimum Hamiltonian path starting at node 0 over a graph defined by a cost matrix.
The cost function need not be symmetric. When the Hamiltonian path is closed, it's a Hamiltonian cycle, i.e. the algorithm solves the Traveling Salesman Problem. Example: std::vector<std::vector<int>> cost_mat; ... fill in cost matrix HamiltonianPathSolver<int, std::vector<std::vector<int>>> mhp(cost_mat); ///< no computation done printf("%d\n", mhp.TravelingSalesmanCost()); ///< computation done and stored In 2010, 26 was the maximum solvable with 24 Gigs of RAM, and it took several minutes. With this 2014 version of the code, one may go a little higher, but considering the complexity of the algorithm (n*2^n), and that there are very good ways to solve TSP with more than 32 cities, we limit ourselves to 32 cites. This is why we define the type NodeSet to be 32-bit wide.
Definition at line 475 of file hamiltonian_path.h.
| typedef Set<Integer> operations_research::HamiltonianPathSolver< CostType, CostFunction >::NodeSet |
Definition at line 476 of file hamiltonian_path.h.
|
explicit |
Definition at line 606 of file hamiltonian_path.h.
| operations_research::HamiltonianPathSolver< CostType, CostFunction >::HamiltonianPathSolver | ( | int | num_nodes, |
| CostFunction | cost | ||
| ) |
Definition at line 611 of file hamiltonian_path.h.
| int operations_research::HamiltonianPathSolver< CostType, CostFunction >::BestHamiltonianPathEndNode | ( | ) |
Returns the end-node that yields the shortest Hamiltonian path of all shortest Hamiltonian path from 0 to end-node (end-node != 0).
Definition at line 830 of file hamiltonian_path.h.
| void operations_research::HamiltonianPathSolver< CostType, CostFunction >::ChangeCostMatrix | ( | CostFunction | cost | ) |
Replaces the cost matrix while avoiding re-allocating memory.
Definition at line 627 of file hamiltonian_path.h.
| void operations_research::HamiltonianPathSolver< CostType, CostFunction >::ChangeCostMatrix | ( | int | num_nodes, |
| CostFunction | cost | ||
| ) |
Definition at line 633 of file hamiltonian_path.h.
| CostType operations_research::HamiltonianPathSolver< CostType, CostFunction >::HamiltonianCost | ( | int | end_node | ) |
Returns the cost of the Hamiltonian path from 0 to end_node.
Definition at line 836 of file hamiltonian_path.h.
| std::vector< int > operations_research::HamiltonianPathSolver< CostType, CostFunction >::HamiltonianPath | ( | int | end_node | ) |
Returns the shortest Hamiltonian path from 0 to end_node.
Definition at line 843 of file hamiltonian_path.h.
| void operations_research::HamiltonianPathSolver< CostType, CostFunction >::HamiltonianPath | ( | std::vector< PathNodeIndex > * | path | ) |
Stores HamiltonianPath(BestHamiltonianPathEndNode()) into *path.
Definition at line 850 of file hamiltonian_path.h.
| bool operations_research::HamiltonianPathSolver< CostType, CostFunction >::IsRobust | ( | ) |
Returns true if there won't be precision issues.
This is always true for integers, but not for floating-point types.
We compute the min and max for the cost matrix.
We determine if the range of the cost matrix is going to make the algorithm not robust because of precision issues.
Definition at line 784 of file hamiltonian_path.h.
| CostType operations_research::HamiltonianPathSolver< CostType, CostFunction >::TravelingSalesmanCost | ( | ) |
Returns the cost of the TSP tour.
Definition at line 857 of file hamiltonian_path.h.
| std::vector< int > operations_research::HamiltonianPathSolver< CostType, CostFunction >::TravelingSalesmanPath | ( | ) |
Returns the TSP tour in the vector pointed to by the argument.
Definition at line 864 of file hamiltonian_path.h.
| void operations_research::HamiltonianPathSolver< CostType, CostFunction >::TravelingSalesmanPath | ( | std::vector< PathNodeIndex > * | path | ) |
Definition at line 870 of file hamiltonian_path.h.
| bool operations_research::HamiltonianPathSolver< CostType, CostFunction >::VerifiesTriangleInequality | ( | ) |
Returns true if the cost matrix verifies the triangle inequality.
Definition at line 809 of file hamiltonian_path.h.