public IGraphColoringSolution Optimize()
{
GraphColoringSolution bestSolution = null;
var solutionInfeasible = false;
var maxColorsAllowed = _nodeAndArcRepository.GetAllNodes().Count();
while (!solutionInfeasible)
{
var domainStore = new DomainStore(_nodeAndArcRepository.GetAllNodes(), maxColorsAllowed);
var scoringFunction = new LexicographicScoringFunction(_nodeAndArcRepository.GetAllNodes(), maxColorsAllowed);
var solution = new GraphColoringSolution();
var firstNode = scoringFunction.GetNewNode();
solutionInfeasible = _searchAlgorithm.SearchFurther(firstNode, 0, domainStore, scoringFunction, solution);
if (!solutionInfeasible)
{
bestSolution = solution;
maxColorsAllowed = solution.GetColorsUsed();
}
//solutionInfeasible = true;
}
return(bestSolution);
}
public LexicographicScoringFunction(LexicographicScoringFunction scoringFunction)
{
this.ScoringDictionary = new SortedDictionary <string, List <Node> >();
this.NodeScore = new Dictionary <Node, string>();
foreach (var score in scoringFunction.ScoringDictionary.Keys)
{
this.ScoringDictionary.Add(score, new List <Node>(scoringFunction.ScoringDictionary[score]));
}
foreach (KeyValuePair <Node, string> keyValuePair in scoringFunction.NodeScore)
{
this.NodeScore.Add(keyValuePair.Key, keyValuePair.Value);
}
}
public bool SearchFurther(Node prevnode, int chosenColor, DomainStore domainStore,
LexicographicScoringFunction scoringFunction, GraphColoringSolution solution)
{
if (domainStore.UpdateDomainStore(prevnode, chosenColor))
{
return(true);
}
scoringFunction.UpdateScore(prevnode, domainStore);
solution.AddSolution(prevnode, chosenColor);
var nextNode = scoringFunction.GetNewNode();
if (solution.NumberOfNodesColored() == domainStore.Domain.Count())
{
return(false);
}
foreach (var colorOption in domainStore.GetPossibleOptions(nextNode).ToList())
{
var solutionRejected = SearchFurther(nextNode, colorOption, new DomainStore(domainStore),
new LexicographicScoringFunction(scoringFunction), solution);
if (solutionRejected)
{
solution.RevertSolution(nextNode);
// if (domainStore.UpdateDomainStoreAfterBacktrack(nextNode, colorOption))
// {
// return true;
// }
}
else
{
return(false);
}
}
return(true);
}
