private void Initialize(SetCoveringProblemData data)
{
_l = new int[PopulationSize, data.N];
_r = new int[data.M];
int t = 0;
var res = new GreedyEngine.Engine().Solve(data);
for (int i = 0; i < data.N; ++i)
{
_l[t, i] = res.Solution[i];
}
//FindNextCovering(data, t, (d, r) => d.Subsets[r].First());
while (t < PopulationSize - 1)
{
t++;
for (int j = 0; j < data.M; ++j)
{
_r[j] = 0;
}
FindNextCovering(data, t, (d, r) => d.Subsets[r][Utility.Random.Next(data.Subsets[r].Count)]);
}
DeleteExcessiveColumns(data);
}
public SetCoveringProblemResult Solve(SetCoveringProblemData data)
{
var res = new GreedyEngine.Engine().Solve(data);
var configuration = res.Solution;
//int upperBound = 10000000;
double tsFactor = 0.2;
int tabuLength = (int)Math.Ceiling(tsFactor
* Utility.NumberOfSubsetsIncover(res.Solution, data.N)) + 1;
int[] solution = new int[data.N];
Array.Copy(res.Solution, solution, data.N);
int solutionFitness = res.SolutionFitness;
int iterations = 0;
List <int> fitnessesHistory = new List <int>();
while (iterations < 2000)
{
iterations++;
List <int[]> neighborhood = new List <int[]>();
List <ConfigurationEntry> sortedNeighborhood = new List <ConfigurationEntry>();
for (int i = 0; i < data.N; ++i)
{
int[] neighbor = new int[data.N];
Array.Copy(configuration, neighbor, data.N);
neighbor[i] = (neighbor[i] + 1) % 2;
neighborhood.Add(neighbor);
sortedNeighborhood.Add(new ConfigurationEntry
{
Index = i,
Fitness = Utility.CalculateConfigurationFitness(data, neighbor, data.N)
});
}
var configurations = sortedNeighborhood.OrderBy(x => x.Fitness).ToList();
var acceptable = configurations.First(x => !BelongsToTabu(neighborhood[x.Index], data.N) ||
x.Fitness < solutionFitness);
Array.Copy(neighborhood[acceptable.Index], configuration, data.N);
if (acceptable.Fitness < solutionFitness && Utility.IsLegalSolution(data, neighborhood[acceptable.Index]))
{
solution = neighborhood[acceptable.Index];
solutionFitness = acceptable.Fitness;
}
if (_tabuList.Count == tabuLength + 2)
{
var first = _tabuList.First();
_tabuList.Remove(first);
}
_tabuList.Add(neighborhood[acceptable.Index]);
fitnessesHistory.Add(solutionFitness);
if (iterations > 100 && fitnessesHistory[iterations - 100] == fitnessesHistory[iterations - 1])
{
break;
}
//Console.WriteLine("iterations: " + iterations);
//Console.WriteLine("fitness: " + solutionFitness);
}
return(new SetCoveringProblemResult()
{
Iterations = iterations,
Solution = solution,
SolutionFitness = solutionFitness
});
}
