public override bool Try(SimulatedAnnealingSolver solverInstance, ref SatConfiguration currentConfiguration)
{
SatConfiguration triedConfiguration;
double randomChoice = random.NextDouble();
if (randomChoice < randomNeighborProb)
{
triedConfiguration = GetRandomNeighbor(solverInstance, currentConfiguration);
}
else if (randomChoice < randomNeighborProb + randomNewProb)
{
triedConfiguration = SatConfiguration.RandomConfiguration(solverInstance.SatInstance, random);
}
else if (randomChoice < randomNeighborProb + randomNewProb + improveScoreProb)
{
triedConfiguration = GetBetterScoreNeighbor(solverInstance, currentConfiguration);
}
else
{
triedConfiguration = GetBetterSatisfiabilityNeighbor(solverInstance, currentConfiguration);
}
triedConfiguration.Score = solverInstance.Options.ScoreStrategy.CalculateScore(triedConfiguration, solverInstance);
if (Accept(triedConfiguration, currentConfiguration, solverInstance.CurrentTemperature))
{
currentConfiguration = triedConfiguration;
return(true);
}
return(false);
}
private SatConfiguration GetBetterScoreNeighbor(SimulatedAnnealingSolver solverInstance, SatConfiguration currentConfiguration)
{
var triedConfiguration = new SatConfiguration(currentConfiguration);
var flipIndex = currentConfiguration.IndexOfRandomToImproveScore(random);
//Nothing to improve (all valuations set to 1), reset the configuration entirely
if (flipIndex < 0)
{
triedConfiguration = SatConfiguration.RandomConfiguration(solverInstance.SatInstance, random);
}
else
{
triedConfiguration.FlipValuation(flipIndex);
}
return(triedConfiguration);
}
public SatConfiguration GetStartingPosition(SimulatedAnnealingSolver solverInstance)
{
return(SatConfiguration.RandomConfiguration(solverInstance.SatInstance, random));
}