internal void GlobalPheromoneUpdate(List <Node> mainSolution, Fitness mainSolutionFitnessValue, List <Edge> edges)
{
foreach (var node in mainSolution)
{
if (mainSolution.Last() == node)
{
break;
}
var nextNode = mainSolution.First(n => n.NurseId == node.NurseId + 1);
var solutionEdge = edges.First(ed => ed.IndexNurseA == node.NurseId && ed.IndexNurseB == nextNode.NurseId && ed.IndexNodeA == node.Index && ed.IndexNodeB == nextNode.Index);
solutionEdge.Pheromone = (1.0 - PARAM_RHO) * solutionEdge.Pheromone + PARAM_RHO * (1 / (1 + mainSolutionFitnessValue.CompleteFitnessValue * PARAM_LAMBDA));
}
}
static void Main(string[] args)
{
var inputData = InputData.GetObjectDataFromFile("Instances/Sprint/sprint02.xml");
ACOHandler handler = new ACOHandler(inputData);
List <Node>[] nodes = handler.GenerationManager.GetShiftPatterns();
//List<Node>[] nodes = NodeTest();
List <Edge> edges = new List <Edge>();
handler.ComputeStaticHeuristic(nodes);
List <Node> mainSolution = handler.ExtractSolution(nodes);
Fitness mainSolutionFitnessValue = handler.ApplySolution(mainSolution).Item1;
handler.InitializeStandardPheromone(mainSolutionFitnessValue);
handler.ListOfEdgesUpdate(mainSolution, edges);
int consecutiveNoImprovements = 0;
Console.Write("Solution construction ");
do
{
Console.Write(".");
List <Ant> ants = Ant.GenerateAnts(NUM_ANTS, handler.CoverRequirements, handler.CoverRequirementsArray);
foreach (var ant in ants)
{
Console.Write(":");
for (int i = 0; i < handler.NurseNumber; i++)
{
//Compute the product between static heuristic and dynamic heuristic
var heuristicInformation = handler.ComputeHeuristicInfo(nodes[i], ant.CoverRequirementsArray);
var selectedIndex = handler.NodeSelection(heuristicInformation, nodes, edges, i);
var selectedNode = nodes[i].ElementAt(selectedIndex);
ant.Solution.Add(selectedNode);
ant.CoverRequirementsArray = heuristicInformation[selectedIndex].Item2;
}
Tuple <Fitness, int[]> antSolutionApplied = handler.ApplySolution(ant.Solution);
int[] antSolutionUpdatedCoverReq = antSolutionApplied.Item2;
//Edges update
handler.ListOfEdgesUpdate(ant.Solution, edges);
if (Fitness.FitnessCompare(antSolutionApplied.Item1, mainSolutionFitnessValue) == 1)
{
mainSolution = ant.Solution;
mainSolutionFitnessValue = antSolutionApplied.Item1;
consecutiveNoImprovements = 0;
Console.Write($" {antSolutionApplied.Item1.UncoveredShifts} + {antSolutionApplied.Item1.TotalOverShift} + {antSolutionApplied.Item1.TotalSolutionCost} ");
}
else
{
consecutiveNoImprovements++;
}
handler.LocalPheromoneUpdate(mainSolution, edges);
}
handler.GlobalPheromoneUpdate(mainSolution, mainSolutionFitnessValue, edges);
} while (consecutiveNoImprovements < NO_IMPROVEMENT_LIMIT);
handler.Evaluator.CalculateSolutionPenalty(mainSolution);
handler.GenerationManager.PrintSolution(mainSolution, mainSolutionFitnessValue);
Console.ReadKey();
}
internal void InitializeStandardPheromone(Fitness fitness)
{
Pheromone_0 = 1.0 / (fitness.CompleteFitnessValue + 1.0);
CurrentPheromone_0 = Pheromone_0;
}