org.chocosolver.solver.search.loop.move

Class MoveBinaryDFS

java.lang.Object

org.chocosolver.solver.search.loop.move.MoveBinaryDFS

All Implemented Interfaces:

Move

Direct Known Subclasses:

MoveBinaryHBFS, MoveBinaryLDS

public class MoveBinaryDFS
extends Object
implements Move

A move dedicated to run a Depth First Search with binary decisions.

Created by cprudhom on 02/09/15. Project: choco.

Since:

3.3.1

Author:

Charles Prud'homme

Field Summary

Fields

Modifier and Type	Field and Description
protected AbstractStrategy	strategy Search strategy to extend the search tree
protected int	topDecisionPosition Index, in the decision path, of the decision taken just before selecting this move.

Constructor Summary

Constructors

Constructor and Description
MoveBinaryDFS() Create this move without any search strategy
MoveBinaryDFS(AbstractStrategy strategy) Create this move with a search strategy

Method Summary

Modifier and Type	Method and Description
boolean	extend(Solver solver) Performs a move when the CSP associated to the current node of the search space is not proven to be not consistent.
List<Move>	getChildMoves() Returns the child moves or null Some Move only accepts one single move as child.
<V extends Variable> AbstractStrategy<V>	getStrategy() Returns the search strategy in use.
boolean	init() Called before the search starts.
protected void	prevDecision(Solver solver) Backtrack in the search tree
boolean	repair(Solver solver) Performs a move when the CSP associated to the current node of the search space is proven to be not consistent.
protected boolean	rewind(Solver solver) Go back in the search tree.
void	setChildMoves(List<Move> someMoves) Overrides this child moves (if possible and if any).
<V extends Variable> void	setStrategy(AbstractStrategy<V> aStrategy) Defines a search strategy, that is, a service which computes and returns decisions.
void	setTopDecisionPosition(int position) Indicates the position of decision made just before selecting this move.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

strategy

protected AbstractStrategy strategy

Search strategy to extend the search tree

topDecisionPosition

protected int topDecisionPosition

Index, in the decision path, of the decision taken just before selecting this move.

Constructor Detail

MoveBinaryDFS

public MoveBinaryDFS()

Create this move without any search strategy

MoveBinaryDFS

public MoveBinaryDFS(AbstractStrategy strategy)

Create this move with a search strategy

Parameters:

strategy - a search strategy

Method Detail

init

public boolean init()

Description copied from interface: Move

Called before the search starts. Also initializes the search strategy.

Specified by:

init in interface Move

Returns:

false if something goes wrong, true otherwise

extend

public boolean extend(Solver solver)

Description copied from interface: Move

Performs a move when the CSP associated to the current node of the search space is not proven to be not consistent.

Specified by:

extend in interface Move

Parameters:

solver - reference the solver

Returns:

true if an extension can be done, false when no more extension is possible.

repair

public boolean repair(Solver solver)

Description copied from interface: Move

Performs a move when the CSP associated to the current node of the search space is proven to be not consistent.

Specified by:

repair in interface Move

Parameters:

solver - reference the solver

Returns:

true if a reparation can be done, false when no more reparation is possible.

setTopDecisionPosition

public void setTopDecisionPosition(int position)

Description copied from interface: Move

Indicates the position of decision made just before selecting this move. When only one "terminal" move is declared, the top decision decision is -1. When dealing with a sequence of Move, the position is the one of the last decision of the previous move. In consequence, when backtracking, the right move can be applied or stopped when needed. This has to be declared on the first call to Move.extend(Solver) and is checked on Move.repair(Solver).

Specified by:

setTopDecisionPosition in interface Move

Parameters:

position - position of the last decision taken before applying this move

getStrategy

public <V extends Variable> AbstractStrategy<V> getStrategy()

Description copied from interface: Move

Returns the search strategy in use.

Specified by:

getStrategy in interface Move

Type Parameters:

V - the type of variable managed by the strategy

Returns:

the current search strategy

setStrategy

public <V extends Variable> void setStrategy(AbstractStrategy<V> aStrategy)

Description copied from interface: Move

Defines a search strategy, that is, a service which computes and returns decisions.

Specified by:

setStrategy in interface Move

Type Parameters:

V - the type of variable managed by the strategy

Parameters:

aStrategy - a search strategy

rewind

protected boolean rewind(Solver solver)

Go back in the search tree. Either refute a decision, or backtrack.

Parameters:

solver - reference to the solver

Returns:

true if a reparation has been found

prevDecision

protected void prevDecision(Solver solver)

Backtrack in the search tree

Parameters:

solver - reference to the solver

getChildMoves

public List<Move> getChildMoves()

Description copied from interface: Move

Returns the child moves or null Some Move only accepts one single move as child.

Specified by:

getChildMoves in interface Move

Returns:

the child moves

setChildMoves

public void setChildMoves(List<Move> someMoves)

Description copied from interface: Move

Overrides this child moves (if possible and if any). Some Move only accepts one single move as child.

Specified by:

setChildMoves in interface Move

Parameters:

someMoves - a new child move