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Google OR-Tools v9.15
a fast and portable software suite for combinatorial optimization
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Base class of the local search operators dedicated to path modifications (a path is a set of nodes linked together by arcs). This family of neighborhoods supposes they are handling next variables representing the arcs (var[i] represents the node immediately after i on a path). Several services are provided:
Definition at line 1529 of file constraint_solveri.h.
#include <constraint_solveri.h>
Classes | |
| struct | IterationParameters |
| Set of parameters used to configure how the neighborhood is traversed. More... | |
| struct | Neighbor |
Public Member Functions | |
| PathOperator (const std::vector< IntVar * > &next_vars, const std::vector< IntVar * > &path_vars, IterationParameters iteration_parameters) | |
| Builds an instance of PathOperator from next and path variables. | |
| PathOperator (const std::vector< IntVar * > &next_vars, const std::vector< IntVar * > &path_vars, int number_of_base_nodes, bool skip_locally_optimal_paths, bool accept_path_end_base, std::function< int(int64_t)> start_empty_path_class, std::function< const std::vector< int > &(int, int)> get_incoming_neighbors, std::function< const std::vector< int > &(int, int)> get_outgoing_neighbors) | |
| ~PathOperator () override | |
| virtual bool | MakeNeighbor ()=0 |
| void | EnterSearch () override |
| void | Reset () override |
| bool | SkipUnchanged (int index) const override |
| int64_t | Next (int64_t node) const |
| Returns the node after node in the current delta. | |
| int64_t | Prev (int64_t node) const |
| Returns the node before node in the current delta. | |
| int64_t | Path (int64_t node) const |
| int | number_of_nexts () const |
| Number of next variables. | |
| Public Member Functions inherited from operations_research::IntVarLocalSearchOperator | |
| IntVarLocalSearchOperator (const std::vector< IntVar * > &vars, bool keep_inverse_values=false) | |
| ~IntVarLocalSearchOperator () override | |
| bool | HoldsDelta () const override |
| void | Start (const Assignment *assignment) override |
| virtual bool | IsIncremental () const |
| int | Size () const |
| int64_t | Value (int64_t index) const |
| IntVar * | Var (int64_t index) const |
| Returns the variable of given index. | |
| int64_t | OldValue (int64_t index) const |
| int64_t | PrevValue (int64_t index) const |
| void | SetValue (int64_t index, int64_t value) |
| bool | Activated (int64_t index) const |
| void | Activate (int64_t index) |
| void | Deactivate (int64_t index) |
| bool | ApplyChanges (Assignment *delta, Assignment *deltadelta) const |
| void | RevertChanges (bool change_was_incremental) |
| void | AddVars (const std::vector< IntVar * > &vars) |
| bool | MakeNextNeighbor (Assignment *delta, Assignment *deltadelta) override |
| Public Member Functions inherited from operations_research::LocalSearchOperator | |
| LocalSearchOperator () | |
| ~LocalSearchOperator () override | |
| virtual const LocalSearchOperator * | Self () const |
| virtual bool | HasFragments () const |
| Public Member Functions inherited from operations_research::BaseObject | |
| BaseObject () | |
| BaseObject (const BaseObject &)=delete | |
| BaseObject & | operator= (const BaseObject &)=delete |
| virtual | ~BaseObject ()=default |
| virtual std::string | DebugString () const |
Protected Member Functions | |
| bool | MakeOneNeighbor () override |
| This method should not be overridden. Override MakeNeighbor() instead. | |
| virtual void | OnNodeInitialization () |
| virtual void | ResetIncrementalism () |
| int64_t | BaseNode (int i) const |
| Returns the ith base node of the operator. | |
| int64_t | BaseAlternativeNode (int i) const |
| Returns the alternative node for the ith base node. | |
| int64_t | BaseSiblingAlternativeNode (int i) const |
| Returns the alternative node for the sibling of the ith base node. | |
| int64_t | StartNode (int i) const |
| Returns the start node of the ith base node. | |
| int64_t | EndNode (int i) const |
| Returns the end node of the ith base node. | |
| const std::vector< int64_t > & | path_starts () const |
| Returns the vector of path start nodes. | |
| int | PathClass (int i) const |
| Returns the class of the path of the ith base node. | |
| int | PathClassFromStartNode (int64_t start_node) const |
| virtual bool | RestartAtPathStartOnSynchronize () |
| virtual bool | OnSamePathAsPreviousBase (int64_t) |
| it's currently way more complicated to implement. | |
| virtual int64_t | GetBaseNodeRestartPosition (int base_index) |
| virtual void | SetNextBaseToIncrement (int64_t base_index) |
| virtual bool | ConsiderAlternatives (int64_t) const |
| int64_t | OldNext (int64_t node) const |
| int64_t | PrevNext (int64_t node) const |
| int64_t | OldPrev (int64_t node) const |
| int64_t | OldPath (int64_t node) const |
| int | CurrentNodePathStart (int64_t node) const |
| int | CurrentNodePathEnd (int64_t node) const |
| bool | MoveChain (int64_t before_chain, int64_t chain_end, int64_t destination) |
| bool | ReverseChain (int64_t before_chain, int64_t after_chain, int64_t *chain_last) |
| bool | SwapNodes (int64_t node1, int64_t node2) |
| Swaps the nodes node1 and node2. | |
| bool | MakeActive (int64_t node, int64_t destination) |
| Insert the inactive node after destination. | |
| bool | MakeChainInactive (int64_t before_chain, int64_t chain_end) |
| bool | SwapActiveAndInactive (int64_t active, int64_t inactive) |
| Replaces active by inactive in the current path, making active inactive. | |
| bool | SwapActiveAndInactiveChains (absl::Span< const int64_t > active_chain, absl::Span< const int64_t > inactive_chain) |
| void | SetNext (int64_t from, int64_t to, int64_t path) |
| Sets 'to' to be the node after 'from' on the given path. | |
| bool | IsPathEnd (int64_t node) const |
| bool | IsPathStart (int64_t node) const |
| Returns true if node is the first node on the path. | |
| bool | IsInactive (int64_t node) const |
| Returns true if node is inactive. | |
| virtual bool | InitPosition () const |
| void | ResetPosition () |
| int | AddAlternativeSet (const std::vector< int64_t > &alternative_set) |
| template<typename PairType> | |
| void | AddPairAlternativeSets (const std::vector< PairType > &pair_alternative_sets) |
| int64_t | GetActiveInAlternativeSet (int alternative_index) const |
| Returns the active node in the given alternative set. | |
| int64_t | GetActiveAlternativeNode (int node) const |
| Returns the active node in the alternative set of the given node. | |
| int | GetSiblingAlternativeIndex (int node) const |
| Returns the index of the alternative set of the sibling of node. | |
| int | GetAlternativeIndex (int node) const |
| Returns the index of the alternative set of the node. | |
| int64_t | GetActiveAlternativeSibling (int node) const |
| bool | CheckChainValidity (int64_t before_chain, int64_t chain_end, int64_t exclude) const |
| bool | HasNeighbors () const |
| Neighbor | GetNeighborForBaseNode (int64_t base_index) const |
| Protected Member Functions inherited from operations_research::IntVarLocalSearchOperator | |
| int64_t | InverseValue (int64_t index) const |
| int64_t | OldInverseValue (int64_t index) const |
| void | AddToAssignment (IntVar *var, int64_t value, bool active, std::vector< int > *assignment_indices, int64_t index, Assignment *assignment) const |
Protected Attributes | |
| const int | number_of_nexts_ |
Friends | |
| class | BaseNodeIterators< PathOperator > |
| class | AlternativeNodeIterator |
| class | NodeNeighborIterator |
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Builds an instance of PathOperator from next and path variables.
Definition at line 1561 of file constraint_solveri.h.
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Definition at line 1600 of file constraint_solveri.h.
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Definition at line 1612 of file constraint_solveri.h.
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Handling node alternatives. Adds a set of node alternatives to the neighborhood. No node can be in two alternatives.
Definition at line 1909 of file constraint_solveri.h.
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Adds all sets of node alternatives of a vector of alternative pairs. No node can be in two alternatives.
Definition at line 1923 of file constraint_solveri.h.
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Returns the alternative node for the ith base node.
Definition at line 1684 of file constraint_solveri.h.
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Returns the ith base node of the operator.
Definition at line 1682 of file constraint_solveri.h.
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Returns the alternative node for the sibling of the ith base node.
Definition at line 1689 of file constraint_solveri.h.
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Returns true if the chain is a valid path without cycles from before_chain to chain_end and does not contain exclude. In particular, rejects a chain if chain_end is not strictly after before_chain on the path. Cycles are detected through chain length overflow.
Definition at line 1961 of file constraint_solveri.h.
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Indicates if alternatives should be considered when iterating over base nodes.
Reimplemented in operations_research::PairRelocateOperator< ignore_path_vars >.
Definition at line 1737 of file constraint_solveri.h.
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Definition at line 1763 of file constraint_solveri.h.
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Definition at line 1759 of file constraint_solveri.h.
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Returns the end node of the ith base node.
Definition at line 1696 of file constraint_solveri.h.
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Reimplemented from operations_research::LocalSearchOperator.
Definition at line 1614 of file constraint_solveri.h.
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Returns the active node in the alternative set of the given node.
Definition at line 1939 of file constraint_solveri.h.
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Returns the active node in the alternative set of the sibling of the given node.
Definition at line 1953 of file constraint_solveri.h.
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Returns the active node in the given alternative set.
Definition at line 1933 of file constraint_solveri.h.
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Returns the index of the alternative set of the node.
Definition at line 1948 of file constraint_solveri.h.
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Returns the index of the node to which the base node of index base_index must be set to when it reaches the end of a path. By default, it is set to the start of the current path. When this method is called, one can only assume that base nodes with indices < base_index have their final position.
Reimplemented in operations_research::ExchangePathStartEndsAndMakeActiveOperator< ignore_path_vars >, operations_research::MakeChainInactiveOperator< ignore_path_vars >, operations_research::MakePairActiveOperator< ignore_path_vars >, operations_research::PairExchangeRelocateOperator< ignore_path_vars >, operations_research::PairNodeSwapActiveOperator< swap_first, ignore_path_vars >, operations_research::PairRelocateOperator< ignore_path_vars >, operations_research::TwoOpt< ignore_path_vars >, and operations_research::TwoOptWithShortestPathOperator< ignore_path_vars >.
Definition at line 1727 of file constraint_solveri.h.
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Definition at line 1988 of file constraint_solveri.h.
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Returns the index of the alternative set of the sibling of node.
Definition at line 1943 of file constraint_solveri.h.
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Definition at line 1976 of file constraint_solveri.h.
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Returns true if the operator needs to restart its initial position at each call to Start()
Definition at line 1900 of file constraint_solveri.h.
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Returns true if node is inactive.
Definition at line 1894 of file constraint_solveri.h.
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Returns true if node is the last node on the path; defined by the fact that node is outside the range of the variable array.
Definition at line 1888 of file constraint_solveri.h.
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Returns true if node is the first node on the path.
Definition at line 1891 of file constraint_solveri.h.
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Insert the inactive node after destination.
Definition at line 1827 of file constraint_solveri.h.
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Makes the nodes on the chain starting after before_chain and ending at chain_end inactive.
Definition at line 1836 of file constraint_solveri.h.
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Implemented in operations_research::Cross< ignore_path_vars >, operations_research::Exchange< ignore_path_vars >, operations_research::ExchangeAndMakeActiveOperator< ignore_path_vars >, operations_research::ExchangePathStartEndsAndMakeActiveOperator< ignore_path_vars >, operations_research::ExchangeSubtrip< ignore_path_vars >, operations_research::ExtendedSwapActiveOperator< ignore_path_vars >, operations_research::GroupPairAndRelocateOperator< ignore_path_vars >, operations_research::IndexPairSwapActiveOperator< ignore_path_vars >, operations_research::LightPairRelocateOperator< ignore_path_vars >, operations_research::LinKernighan< ignore_path_vars >, operations_research::MakeActiveAndRelocateOperator< ignore_path_vars >, operations_research::MakeActiveOperator< ignore_path_vars >, operations_research::MakeChainInactiveOperator< ignore_path_vars >, operations_research::MakeInactiveOperator< ignore_path_vars >, operations_research::MakePairActiveOperator< ignore_path_vars >, operations_research::MakePairInactiveOperator< ignore_path_vars >, operations_research::MakeRelocateNeighborsOperator< ignore_path_vars >, operations_research::PairExchangeOperator< ignore_path_vars >, operations_research::PairExchangeRelocateOperator< ignore_path_vars >, operations_research::PairNodeSwapActiveOperator< swap_first, ignore_path_vars >, operations_research::PairRelocateOperator< ignore_path_vars >, operations_research::PathLns< ignore_path_vars >, operations_research::Relocate< ignore_path_vars >, operations_research::RelocateAndMakeActiveOperator< ignore_path_vars >, operations_research::RelocateAndMakeInactiveOperator< ignore_path_vars >, operations_research::RelocateExpensiveChain< ignore_path_vars >, operations_research::RelocateSubtrip< ignore_path_vars >, operations_research::SwapActiveChainOperator< ignore_path_vars >, operations_research::SwapActiveOperator< ignore_path_vars >, operations_research::SwapActiveToShortestPathOperator< ignore_path_vars >, operations_research::TSPLns< ignore_path_vars >, operations_research::TSPOpt< ignore_path_vars >, operations_research::TwoOpt< ignore_path_vars >, and operations_research::TwoOptWithShortestPathOperator< ignore_path_vars >.
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This method should not be overridden. Override MakeNeighbor() instead.
Reimplemented from operations_research::IntVarLocalSearchOperator.
Reimplemented in operations_research::RelocateExpensiveChain< ignore_path_vars >, and operations_research::TSPLns< ignore_path_vars >.
Definition at line 1659 of file constraint_solveri.h.
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Moves the chain starting after the node before_chain and ending at the node chain_end after the node destination
Definition at line 1767 of file constraint_solveri.h.
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Returns the node after node in the current delta.
Definition at line 1635 of file constraint_solveri.h.
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Number of next variables.
Definition at line 1655 of file constraint_solveri.h.
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Definition at line 1739 of file constraint_solveri.h.
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Definition at line 1754 of file constraint_solveri.h.
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Definition at line 1749 of file constraint_solveri.h.
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Called by OnStart() after initializing node information. Should be overridden instead of OnStart() to avoid calling PathOperator::OnStart explicitly.
Definition at line 1674 of file constraint_solveri.h.
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it's currently way more complicated to implement.
Returns true if a base node has to be on the same path as the "previous" base node (base node of index base_index - 1). Useful to limit neighborhood exploration to nodes on the same path.
Reimplemented in operations_research::ExchangeAndMakeActiveOperator< ignore_path_vars >, operations_research::MakeChainInactiveOperator< ignore_path_vars >, operations_research::MakePairActiveOperator< ignore_path_vars >, operations_research::PairExchangeRelocateOperator< ignore_path_vars >, operations_research::PairNodeSwapActiveOperator< swap_first, ignore_path_vars >, operations_research::PairRelocateOperator< ignore_path_vars >, operations_research::Relocate< ignore_path_vars >, operations_research::SwapActiveChainOperator< ignore_path_vars >, operations_research::TwoOpt< ignore_path_vars >, and operations_research::TwoOptWithShortestPathOperator< ignore_path_vars >.
Definition at line 1721 of file constraint_solveri.h.
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Returns the index of the path to which node belongs in the current delta. Only returns a valid value if path variables are taken into account.
Definition at line 1649 of file constraint_solveri.h.
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Returns the vector of path start nodes.
Definition at line 1698 of file constraint_solveri.h.
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Returns the class of the path of the ith base node.
Definition at line 1700 of file constraint_solveri.h.
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Definition at line 1701 of file constraint_solveri.h.
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Returns the node before node in the current delta.
Definition at line 1641 of file constraint_solveri.h.
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Definition at line 1744 of file constraint_solveri.h.
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Reimplemented from operations_research::LocalSearchOperator.
Definition at line 1618 of file constraint_solveri.h.
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When entering a new search or using metaheuristics, path operators reactivate optimal routes and iterating re-starts at route starts, which can potentially be out of sync with the last incremental moves. This requires resetting incrementalism.
Reimplemented in operations_research::SwapActiveChainOperator< ignore_path_vars >, and operations_research::TwoOpt< ignore_path_vars >.
Definition at line 1679 of file constraint_solveri.h.
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Reset the position of the operator to its position when Start() was last called; this can be used to let an operator iterate more than once over the paths.
Definition at line 1904 of file constraint_solveri.h.
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When the operator is being synchronized with a new solution (when Start() is called), returns true to restart the exploration of the neighborhood from the start of the last paths explored; returns false to restart the exploration at the last nodes visited. This is used to avoid restarting on base nodes which have changed paths, leading to potentially skipping neighbors.
Reimplemented in operations_research::MakePairActiveOperator< ignore_path_vars >, operations_research::PairNodeSwapActiveOperator< swap_first, ignore_path_vars >, and operations_research::TwoOptWithShortestPathOperator< ignore_path_vars >.
Definition at line 1714 of file constraint_solveri.h.
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Reverses the chain starting after before_chain and ending before after_chain
Definition at line 1791 of file constraint_solveri.h.
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Sets 'to' to be the node after 'from' on the given path.
Definition at line 1877 of file constraint_solveri.h.
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Set the next base to increment on next iteration. All base > base_index will be reset to their start value.
Definition at line 1732 of file constraint_solveri.h.
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Reimplemented from operations_research::IntVarLocalSearchOperator.
Definition at line 1624 of file constraint_solveri.h.
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Returns the start node of the ith base node.
Definition at line 1694 of file constraint_solveri.h.
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Replaces active by inactive in the current path, making active inactive.
Definition at line 1854 of file constraint_solveri.h.
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Swaps both chains, making nodes on active_chain inactive and inserting active_chain at the position where inactive_chain was.
Definition at line 1861 of file constraint_solveri.h.
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Swaps the nodes node1 and node2.
Definition at line 1815 of file constraint_solveri.h.
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Definition at line 2425 of file constraint_solveri.h.
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Definition at line 2422 of file constraint_solveri.h.
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Definition at line 2426 of file constraint_solveri.h.
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Definition at line 1994 of file constraint_solveri.h.