Module org.chocosolver

Package org.chocosolver.solver.constraints.nary.tree

Class PropAntiArborescences

java.lang.Object

org.chocosolver.solver.constraints.Propagator<IntVar>

org.chocosolver.solver.constraints.nary.tree.PropAntiArborescences

All Implemented Interfaces:

Comparable<Propagator>, ICause, Identity

public class PropAntiArborescences
extends Propagator<IntVar>

AntiArborescences propagation (simplification from tree constraint) based on dominators loops (i.e., variables such that x[i]=i) are considered as roots Can use the simple LT algorithm which runs in O(m.log(n)) worst case time Or a slightly more sophisticated one, linear in theory but not necessarily faster in practice

Author:

Jean-Guillaume Fages

Field Summary

Fields inherited from class org.chocosolver.solver.constraints.Propagator

ACTIVE, constraint, DEFAULT_EXPL, model, operations, OUTPUT_DEFAULT_EXPL, priority, reactToFineEvt, state, vars

Constructor Summary

Constructors

Constructor	Description
PropAntiArborescences(IntVar[] succs, int offSet, boolean linear)	AntiArborescences propagation (simplification from tree constraint) based on dominators

Method Summary

Modifier and Type	Method	Description
ESat	isEntailed()	Check wether this is entailed according to the current state of its internal structure.
void	propagate(int evtmask)	Call the main filtering algorithm to apply to the Domain of the Variable objects.

Methods inherited from class org.chocosolver.solver.constraints.Propagator

addVariable, arity, compareTo, defaultExplain, doFinePropagation, doFlush, doSchedule, doScheduleEvent, dynPriority, equals, explain, fails, forcePropagate, forcePropagationOnBacktrack, forEachIntVar, getConstraint, getId, getModel, getNbVars, getPosition, getPriority, getPropagationConditions, getVar, getVars, getVIndice, getVIndices, hashCode, isActive, isCompletelyInstantiated, isPassive, isReified, isReifiedAndSilent, isScheduled, isStateLess, linkVariables, propagate, reactToFineEvent, reifiedWith, setActive, setActive0, setPassive, setPosition, setReifiedSilent, setReifiedTrue, setVIndices, toString, unlinkVariables, unschedule

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

PropAntiArborescences

public PropAntiArborescences(IntVar[] succs,
                             int offSet,
                             boolean linear)

AntiArborescences propagation (simplification from tree constraint) based on dominators

Parameters:

succs - array of integer variables

offSet - int

linear - boolean

Method Detail

propagate

public void propagate(int evtmask)
               throws ContradictionException

Description copied from class: Propagator

Call the main filtering algorithm to apply to the Domain of the Variable objects. It considers the current state of this objects to remove some values from domains and/or instantiate some variables. Calling this method is done from 2 (and only 2) steps:
- at the initial propagation step,
- when involved in a reified constraint.
It should initialized the internal data structure and apply filtering algorithm from scratch.

Specified by:

propagate in class Propagator<IntVar>

Parameters:

evtmask - type of propagation event this must consider.

Throws:

ContradictionException - when a contradiction occurs, like domain wipe out or other incoherencies.

isEntailed

public ESat isEntailed()

Description copied from class: Propagator

Check wether this is entailed according to the current state of its internal structure. At least, should check the satisfaction of this (when all is instantiated).

Specified by:

isEntailed in class Propagator<IntVar>

Returns:

ESat.TRUE if entailed, ESat.FALSE if not entailed, ESat.UNDEFINED if unknown