content: /**
   * Copyright (c) 2017 Siemens AG
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   * 
   * 1) Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   * 
   * 2) Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package at.ac.tuwien.kr.alpha.core.solver.heuristics;
  
  import at.ac.tuwien.kr.alpha.core.common.Assignment;
  import at.ac.tuwien.kr.alpha.core.common.NoGood;
  import at.ac.tuwien.kr.alpha.core.solver.ChoiceManager;
  import at.ac.tuwien.kr.alpha.core.solver.heuristics.activity.BodyActivityProviderFactory.BodyActivityType;
  
  import static at.ac.tuwien.kr.alpha.core.programs.atoms.Literals.atomOf;
  
  import java.util.HashSet;
  import java.util.Random;
  import java.util.Set;
  
  /**
   * {@link DependencyDrivenHeuristic} needs to know a lot about the structure of nogoods, i.e. the role their members play in rules.
   * However, the solving component of Alpha usually deals only with nogoods and cannot naturally access this information.
   * Therefore, {@link GeneralizedDependencyDrivenHeuristic} both generalizes and simplifies {@link DependencyDrivenHeuristic}
   * by redefining the set of atoms dependent on a choice point.
   * This set is constructed by adding to it, every time a new nogood containing a choice point is added to the stack,
   * all other atoms in the nogood.
   * To choose an atom, {@link GeneralizedDependencyDrivenHeuristic} then proceeds as {@link DependencyDrivenHeuristic}.
   * Because {@link GeneralizedDependencyDrivenHeuristic} does not know the head belonging to a choice point,
   * it just uses the {@link BerkMin} method to choose a truth value.
  
   * Copyright (c) 2017 Siemens AG
   *
   */
  public class GeneralizedDependencyDrivenHeuristic extends DependencyDrivenHeuristic {
  
  	public GeneralizedDependencyDrivenHeuristic(Assignment assignment, ChoiceManager choiceManager, int decayPeriod, double decayFactor, Random random, BodyActivityType bodyActivityType) {
  		super(assignment, choiceManager, decayPeriod, decayFactor, random, bodyActivityType);
  	}
  
  	public GeneralizedDependencyDrivenHeuristic(Assignment assignment, ChoiceManager choiceManager, Random random, BodyActivityType bodyActivityType) {
  		super(assignment, choiceManager, random, bodyActivityType);
  	}
  
  	public GeneralizedDependencyDrivenHeuristic(Assignment assignment, ChoiceManager choiceManager, Random random) {
  		super(assignment, choiceManager, random);
  	}
  
  	@Override
  	protected void recordAtomRelationships(NoGood noGood) {
  		// TODO: use HeapOfActiveChoicePoints.recordAtomRelationships, which does similar things
  		int body = DEFAULT_CHOICE_ATOM;
  		Set<Integer> others = new HashSet<>();
  		for (int literal : noGood) {
  			int atom = atomOf(literal);
  			if (body == DEFAULT_CHOICE_ATOM && choiceManager.isAtomChoice(atom)) {
  				body = atom;
  			} else {
  				others.add(atom);
  			}
  		}
  		for (Integer atom : others) {
  			atomsToBodiesAtoms.put(atom, body);
  			bodyAtomToLiterals.put(body, atom);
  		}
  	}
  
  	@Override
  	protected int getAtomForChooseSign(int atom) {
  		return atom;
  	}
  
  }
  