org.cpsolver.ifs.assignment

Class DefaultSingleAssignment<V extends Variable<V,T>,T extends Value<V,T>>

java.lang.Object

org.cpsolver.ifs.assignment.AssignmentAbstract<V,T>

org.cpsolver.ifs.assignment.DefaultSingleAssignment<V,T>

Type Parameters:

V - Variable

T - Value

All Implemented Interfaces:

Assignment<V,T>

public class DefaultSingleAssignment<V extends Variable<V,T>,T extends Value<V,T>>
extends AssignmentAbstract<V,T>

An assignment using the old Variable.getAssignment() to store values of all the variables of the model. Besides of that, a set of assigned variables is kept in memory. It is fast, but there can be only one such assignment at a time. Ideal for single threaded solvers. Also used as a default assignment, see Model.getDefaultAssignment(). Used by Solver where there is only one assignment kept in memory.

Version:

IFS 1.3 (Iterative Forward Search)
Copyright (C) 2014 Tomáš Müller
muller@unitime.org
http://muller.unitime.org

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not see http://www.gnu.org/licenses.

Author:

Tomáš Müller

See Also:

Assignment, Solver

Field Summary

Fields inherited from class org.cpsolver.ifs.assignment.AssignmentAbstract

iContexts, iHasInitialzedContext

Constructor Summary

Constructors

Constructor and Description
DefaultSingleAssignment()

Method Summary

Modifier and Type	Method and Description
Collection<V>	assignedVariables() The list of assigned variables in the assignment.
int	getIndex() Assignment index.
long	getIteration(V variable) Returns iteration of the last assignment.
protected T	getValueInternal(V variable) Returns assignment of a variable, null if not assigned.
protected void	setValueInternal(long iteration, V variable, T value) Sets an assignment to a variable (unassigns a variable if the given value is null).

Methods inherited from class org.cpsolver.ifs.assignment.AssignmentAbstract

assign, assign, assignedValues, clearContext, ensureInitializedContext, getAssignmentContext, getValue, nrAssignedVariables, nrUnassignedVariables, unassign, unassign, unassignedVariables

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultSingleAssignment

public DefaultSingleAssignment()

Method Detail

getIteration

public long getIteration(V variable)

Description copied from interface: Assignment

Returns iteration of the last assignment. Replacement for Variable.getLastIteration().

Parameters:

variable - problem variable

Returns:

iteration of the last assignment

assignedVariables

public Collection<V> assignedVariables()

Description copied from interface: Assignment

The list of assigned variables in the assignment. That is all the variables that Assignment.getValue(Variable) is not null in this assignment. Replacement for Model.assignedVariables().

Returns:

a collection of assigned variable in this assignment

getValueInternal

protected T getValueInternal(V variable)

Description copied from class: AssignmentAbstract

Returns assignment of a variable, null if not assigned. To be implemented.

Specified by:

getValueInternal in class AssignmentAbstract<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

variable - a variable in question

Returns:

assigned value

setValueInternal

protected void setValueInternal(long iteration,
                                V variable,
                                T value)

Description copied from class: AssignmentAbstract

Sets an assignment to a variable (unassigns a variable if the given value is null). To be implemented.

Specified by:

setValueInternal in class AssignmentAbstract<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

iteration - current iteration

variable - a variable to be assigned

value - new assignment, null if to be unassigned

getIndex

public int getIndex()

Description copied from interface: Assignment

Assignment index. Unique identification of the assignment, starting with zero. This can be used to increase the speed of the search by storing individual values on the variables and an array (indexed by this number).

Specified by:

getIndex in interface Assignment<V extends Variable<V,T>,T extends Value<V,T>>

Overrides:

getIndex in class AssignmentAbstract<V extends Variable<V,T>,T extends Value<V,T>>

Returns:

assignment index, -1 if not to be used