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Open-source constraint solver.
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/**
 * Copyright (c) 2016, Ecole des Mines de Nantes
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the .
 * 4. Neither the name of the  nor the
 *    names of its contributors may be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY  ''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  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
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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package org.chocosolver.solver.constraints.nary.binPacking;

import org.chocosolver.memory.IStateInt;
import org.chocosolver.solver.constraints.Propagator;
import org.chocosolver.solver.constraints.PropagatorPriority;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.variables.IntVar;
import org.chocosolver.solver.variables.delta.IIntDeltaMonitor;
import org.chocosolver.util.ESat;
import org.chocosolver.util.procedure.UnaryIntProcedure;

/**
 * Propagator for a Bin Packing constraint
 * Propagates item/bin allocations to bin loads
 * Reacts to item/bin allocation variables only
 *
 * Should be used together with PropLoadToItem
 *
 * @author Jean-Guillaume Fages
 */
public class PropItemToLoad extends Propagator {

	//***********************************************************************************
	// VARIABLES
	//***********************************************************************************

	private int nbItems, nbAvailableBins, offset;
	private int[] itemSize;
	private IntVar[] binOfItem, binLoad;

	// backtrackable counters
	private IStateInt[] minLoad, maxLoad;

	// structure allowing iteration over removed values since last call
	private IIntDeltaMonitor[] monitors;

	// method to be called for each removed value
	private UnaryIntProcedure procedure = new UnaryIntProcedure() {
		int item;
		@Override
		public UnaryIntProcedure set(Integer itemIdx) {
			item = itemIdx;
			return this;
		}
		@Override
		public void execute(int bin) throws ContradictionException {
			bin -= offset;
			if(bin>=0 && bin =0 && val= offset && val=0 && bin =nbAvailableBins+offset){
					return ESat.FALSE;
				}
			}
		}
		for(int b=0; b binLoad[b].getUB() || max < binLoad[b].getLB()){
				return ESat.FALSE;
			}
		}
		if(isCompletelyInstantiated()){
			return ESat.TRUE;
		}
		return ESat.UNDEFINED;
	}
}