operations_research::RoutingIndexManager Class Reference

Manager for any NodeIndex <-> variable index conversion. More...

Detailed Description

Manager for any NodeIndex <-> variable index conversion.

The routing solver uses variable indices internally and through its API. These variable indices are tricky to manage directly because one Node can correspond to a multitude of variables, depending on the number of times they appear in the model, and if they're used as start and/or end points. This class aims to simplify variable index usage, allowing users to use NodeIndex instead. Usage:

auto starts_ends = ...;  
RoutingIndexManager manager(10, 4, starts_ends);  
RoutingModel model(manager);

Then, use 'manager.NodeToIndex(node)' whenever model requires a variable index.

Note

the mapping between node indices and variables indices is subject to change so no assumption should be made on it. The only guarantee is that indices range between 0 and n-1, where n = number of vehicles * 2 (for start and end nodes) + number of non-start or end nodes.

Definition at line 57 of file routing_index_manager.h.

#include <routing_index_manager.h>

Public Types
typedef RoutingNodeIndex	NodeIndex

Public Member Functions
	RoutingIndexManager (int num_nodes, int num_vehicles, NodeIndex depot)
	Creates a NodeIndex to variable index mapping for a problem containing 'num_nodes', 'num_vehicles' and the given starts and ends for each vehicle. If used, any start/end arrays have to have exactly 'num_vehicles' elements.
	RoutingIndexManager (int num_nodes, int num_vehicles, const std::vector< NodeIndex > &starts, const std::vector< NodeIndex > &ends)
	Creates a NodeIndex to variable index mapping.
	RoutingIndexManager (int num_nodes, int num_vehicles, const std::vector< std::pair< NodeIndex, NodeIndex > > &starts_ends)
	Creates a NodeIndex to variable index mapping.
int	num_nodes () const
int	num_vehicles () const
int	num_indices () const
int64_t	GetStartIndex (int vehicle) const
int64_t	GetEndIndex (int vehicle) const
int64_t	NodeToIndex (NodeIndex node) const
std::vector< int64_t >	NodesToIndices (const std::vector< NodeIndex > &nodes) const
NodeIndex	IndexToNode (int64_t index) const
std::vector< NodeIndex >	IndicesToNodes (absl::Span< const int64_t > indices) const
int	num_unique_depots () const
std::vector< NodeIndex >	GetIndexToNodeMap () const

Static Public Attributes
static const int64_t	kUnassigned = -1

Member Typedef Documentation

NodeIndex

typedef RoutingNodeIndex operations_research::RoutingIndexManager::NodeIndex

Examples

vrp_drop_nodes.cc, vrp_resources.cc, vrp_time_windows.cc, and vrp_with_time_limit.cc.

Definition at line 59 of file routing_index_manager.h.

Constructor & Destructor Documentation

RoutingIndexManager() [1/3]

operations_research::RoutingIndexManager::RoutingIndexManager	(	int	num_nodes,
		int	num_vehicles,
		NodeIndex	depot )

Creates a NodeIndex to variable index mapping for a problem containing 'num_nodes', 'num_vehicles' and the given starts and ends for each vehicle. If used, any start/end arrays have to have exactly 'num_vehicles' elements.

Parameters

num_nodes	Number of nodes in the problem.
num_vehicles	Number of vehicles in the problem.
depot	start and end NodeIndex for all vehicles.

Definition at line 29 of file routing_index_manager.cc.

RoutingIndexManager() [2/3]

operations_research::RoutingIndexManager::RoutingIndexManager	(	int	num_nodes,
		int	num_vehicles,
		const std::vector< NodeIndex > &	starts,
		const std::vector< NodeIndex > &	ends )

Creates a NodeIndex to variable index mapping.

Parameters

num_nodes	Number of nodes in the problem.
num_vehicles	Number of vehicles in the problem.
starts	Array containing the start NodeIndex for each vehicle.
ends	Array containing the end NodeIndex for each vehicle.

Note

starts and ends arrays must have exactly num_vehicles elements.

Definition at line 35 of file routing_index_manager.cc.

RoutingIndexManager() [3/3]

operations_research::RoutingIndexManager::RoutingIndexManager	(	int	num_nodes,
		int	num_vehicles,
		const std::vector< std::pair< NodeIndex, NodeIndex > > &	starts_ends )

Creates a NodeIndex to variable index mapping.

Parameters

num_nodes	Number of nodes in the problem.
num_vehicles	Number of vehicles in the problem.
starts_ends	Array containing a pair [start,end] NodeIndex for each vehicle.

Note

starts_ends arrays must have exactly num_vehicles elements.

Definition at line 47 of file routing_index_manager.cc.

Member Function Documentation

GetEndIndex()

int64_t operations_research::RoutingIndexManager::GetEndIndex ( int vehicle ) const

inline

Definition at line 102 of file routing_index_manager.h.

GetIndexToNodeMap()

std::vector< NodeIndex > operations_research::RoutingIndexManager::GetIndexToNodeMap ( ) const

inline

Definition at line 129 of file routing_index_manager.h.

GetStartIndex()

int64_t operations_research::RoutingIndexManager::GetStartIndex ( int vehicle ) const

inline

Definition at line 99 of file routing_index_manager.h.

IndexToNode()

NodeIndex operations_research::RoutingIndexManager::IndexToNode ( int64_t index ) const

inline

Definition at line 117 of file routing_index_manager.h.

IndicesToNodes()

std::vector< RoutingIndexManager::NodeIndex > operations_research::RoutingIndexManager::IndicesToNodes

(

absl::Span< const int64_t >

indices

)

const

Definition at line 138 of file routing_index_manager.cc.

NodesToIndices()

std::vector< int64_t > operations_research::RoutingIndexManager::NodesToIndices

(

const std::vector< NodeIndex > &

nodes

)

const

Definition at line 126 of file routing_index_manager.cc.

NodeToIndex()

int64_t operations_research::RoutingIndexManager::NodeToIndex ( NodeIndex node ) const

inline

Definition at line 107 of file routing_index_manager.h.

num_indices()

int operations_research::RoutingIndexManager::num_indices ( ) const

inline

Definition at line 97 of file routing_index_manager.h.

num_nodes()

int operations_research::RoutingIndexManager::num_nodes ( ) const

inline

Definition at line 93 of file routing_index_manager.h.

num_unique_depots()

int operations_research::RoutingIndexManager::num_unique_depots ( ) const

inline

Definition at line 128 of file routing_index_manager.h.

num_vehicles()

int operations_research::RoutingIndexManager::num_vehicles ( ) const

inline

Definition at line 95 of file routing_index_manager.h.

Member Data Documentation

kUnassigned

const int64_t operations_research::RoutingIndexManager::kUnassigned = -1

static

Definition at line 60 of file routing_index_manager.h.

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The documentation for this class was generated from the following files:

• ortools/constraint_solver/routing_index_manager.h
• ortools/constraint_solver/routing_index_manager.cc