import choco.kernel.solver.search.integer.AbstractIntVarSelector;
import choco.kernel.solver.variables.integer.IntDomainVar;
import choco.kernel.solver.variables.AbstractVar;
import choco.kernel.memory.IStateInt;

public class MagicHeuristic extends AbstractIntVarSelector {

    private IntDomainVar[] vars;                // 0/1 decision variables
    private int n;                              // number of decision variables
    private IStateInt[] deg;                    // number of vertices adjacent to v[i] in candidate set, reversible
    private int[] saturation;                   // colouring of v[i] in candidate set
    private ReversibleSortedArray candidateSet; // the uninstantiated variables

    public MagicHeuristic(IntDomainVar[] vars,IStateInt[] deg,int[] saturation,ReversibleSortedArray candidateSet){
	this.vars = vars; n = vars.length; this.saturation = saturation; this.deg = deg; this.candidateSet = candidateSet;
    }
    
    public IntDomainVar selectIntVar(){
	int maxSaturation     = Integer.MIN_VALUE;
	int minDeg            = Integer.MAX_VALUE;
	IntDomainVar magicVar = null;
	int i                 = 0;
	for (int k=0;k<candidateSet.size();k++){
	    i = candidateSet.get(k);
	    if (saturation[i] > maxSaturation ||saturation[i] == maxSaturation && deg[i].get() < minDeg){
		magicVar = vars[i];
		maxSaturation = saturation[i];
		minDeg = deg[i].get();
	    }     
	}
	return magicVar;
    }
    //
    // select the uninstantiated variable with maximum saturation and min degree
    // we expect this will behave as max colour
    //
}