//protected Random _random = new Random(0);
/// <summary>
/// Liefert die nächste zu belegende Variable zurück.
/// </summary>
/// <remarks>Die Auswahl findet dabei
/// über die MRV-Heuristic statt(Minimum Remaining Values).
/// Haben mehrere Variablen die gleiche Anzahl verbleibender Werte, dann
/// wird die GradHeuristic genutzt, d.h. es wird die Variable genommen, die in
/// den meisten Randbedingungen vorkommt.
/// </remarks>
/// <param name="configuration">Die Konfiguration, die noch nicht belegte Variablen enthält.</param>
/// <param name="constraintList">Die Liste mit den Randbedingungen.</param>
/// <returns>
/// Gibt die als nächstes zu belegende Variable zurück.
/// </returns>
public Variable GetHeuristicVariable(ConstraintConfiguration configuration, ConstraintList constraintList)
{
Variable result = null;
int minDomainValues = 0;
List <Variable> mrvVariables = new List <Variable>();
//// Zufall
//SortedList<double, Variable> sortedList = new SortedList<double, Variable>(configuration.Variables.GetLength(0));
//foreach (Variable var in configuration.Variables)
//{
// sortedList.Add(_random.NextDouble(), var);
//}
//// search the variables with the minimum remaining values
//foreach(Variable var in sortedList.Values)
foreach (Variable var in configuration.Variables)
{
if (!var.HasAsignedValue)
{
if (result == null)
{
result = var;
minDomainValues = var.Domain.Count;
mrvVariables.Add(var);
}
else if (minDomainValues > var.Domain.Count)
{
mrvVariables.Clear();
result = var;
minDomainValues = var.Domain.Count;
mrvVariables.Add(var);
}
else if (minDomainValues == var.Domain.Count)
{
mrvVariables.Add(var);
}
}
}
// are there more then one variables we should use the variable with the most constraints
if (mrvVariables.Count != 1)
{
int countConstraints = 0;
int varCountConstraints = 0;
foreach (Variable var in mrvVariables)
{
varCountConstraints = constraintList.GetConstraints(var.Name).Count;
if (varCountConstraints > countConstraints)
{
result = var;
countConstraints = varCountConstraints;
}
}
}
return(result);
}
/// <summary>
/// Generates an object from its XML representation.
/// </summary>
/// <param name="reader">The <see cref="T:System.Xml.XmlReader"/> stream from which the object is deserialized.</param>
public void ReadXml(XmlReader reader)
{
// die Variablenoperatoren werden im Problem gemerkt
// Das Dictionary kann später wieder geleert werden, wenn die Variablenoperatoren in den Constraints sind
VariablesOperator.VarOperatorList.Clear();
reader.Read();
_xmlVersion = reader.ReadElementContentAsString();
XmlSerializer xmlSerializer;
if (reader.Name == "ConstraintConfiguration")
{
xmlSerializer = new XmlSerializer(typeof(ConstraintConfiguration));
_begin = CreateNode(null, xmlSerializer.Deserialize(reader) as ConstraintConfiguration);
//_begin.Data = xmlSerializer.Deserialize(reader) as ConstraintConfiguration;
}
xmlSerializer = new XmlSerializer(typeof(ConstraintList));
_constraintList = xmlSerializer.Deserialize(reader) as ConstraintList;
reader.Read();
VariablesOperator.VarOperatorList.Clear();
}
