operations_research::DobbleOperator Class Reference

Local Search. More...

Inheritance diagram for operations_research::DobbleOperator:

List of all members.

Public Member Functions
	DobbleOperator (const IntVar *const *card_symbol_vars, int num_vars, int num_cards, int num_symbols, int num_symbols_per_card)
virtual	~DobbleOperator ()
Protected Member Functions
virtual void	OnStart ()
	OnStart() simply stores the current symbols per card in symbols_per_card_, and defers further initialization to the subclass's InitNeighborhoodSearch() method.
virtual void	InitNeighborhoodSearch ()=0
int	VarIndex (int card, int symbol)
	Find the index of the variable corresponding to the given symbol on the given card.
void	SwapTwoSymbolsOnCards (int card1, int symbol1, int card2, int symbol2)
	Move symbol1 from card1 to card2, and symbol2 from card2 to card1.
Protected Attributes
const int	num_cards_
const int	num_symbols_
const int	num_symbols_per_card_
std::vector< std::vector< int > >	symbols_per_card_

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Detailed Description

Local Search.

The "local search", or "local neighborhood search", works like this: starting from a given solution to the problem, other solutions in its neighborhood are generated from it, some of them might be selected (because they're better, for example) to become a starting point for other neighborhood searches, and so on.. The detailed search algorithm can vary and depends on the problem to solve.

The fundamental building block for the local search is the "search operator", which has three fundamental methods in its API:

• Its constructor, which keeps (mutable) references to the solver's internal variables (here, the card symbol variables).

• OnStart(), which is called at the start of a local search, and after each solution (i.e. when the local search starts again from that new solution). The solver variables are supposed to represent a valid solution at this point. This method is used by the search operator to initialize its state and be ready to start the exploration of the neighborhood of the given solution.

• MakeOneNeighbor(), which picks a neighbor of the initial solution, and changes the solver's internal variables accordingly to represent that new state.

All local search operators on this problem will derive from the parent class below, which contains some shared code to store a compact representation of which symbols appeal on each cards.

Definition at line 238 of file dobble_ls.cc.

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Constructor & Destructor Documentation

operations_research::DobbleOperator::DobbleOperator	(	const IntVar *const *	card_symbol_vars,
		int	num_vars,
		int	num_cards,
		int	num_symbols,
		int	num_symbols_per_card
	)			[inline]

Definition at line 240 of file dobble_ls.cc.

virtual operations_research::DobbleOperator::~DobbleOperator

(

)

[inline, virtual]

Definition at line 259 of file dobble_ls.cc.

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Member Function Documentation

virtual void operations_research::DobbleOperator::OnStart

(

)

[inline, protected, virtual]

OnStart() simply stores the current symbols per card in symbols_per_card_, and defers further initialization to the subclass's InitNeighborhoodSearch() method.

Definition at line 265 of file dobble_ls.cc.

virtual void operations_research::DobbleOperator::InitNeighborhoodSearch

(

)

[protected, pure virtual]

Implemented in operations_research::SwapSymbolsOnCardPairs.

int operations_research::DobbleOperator::VarIndex	(	int	card,
		int	symbol
	)			[inline, protected]

Find the index of the variable corresponding to the given symbol on the given card.

Definition at line 282 of file dobble_ls.cc.

void operations_research::DobbleOperator::SwapTwoSymbolsOnCards	(	int	card1,
		int	symbol1,
		int	card2,
		int	symbol2
	)			[inline, protected]

Move symbol1 from card1 to card2, and symbol2 from card2 to card1.

Definition at line 287 of file dobble_ls.cc.

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Member Data Documentation

const int operations_research::DobbleOperator::num_cards_ [protected]

Definition at line 294 of file dobble_ls.cc.

const int operations_research::DobbleOperator::num_symbols_ [protected]

Definition at line 295 of file dobble_ls.cc.

const int operations_research::DobbleOperator::num_symbols_per_card_ [protected]

Definition at line 296 of file dobble_ls.cc.

std::vector<std::vector<int> > operations_research::DobbleOperator::symbols_per_card_ [protected]

Definition at line 297 of file dobble_ls.cc.

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

• or-tools/examples/cpp/dobble_ls.cc