public List <City> SimulatedAnnealing(string path)
{
double temperature = 10000;
double alpha = 0.9999;
double minimTemperature = 0.00001;
Cities = new List <City>();
FileReaderHelper.ReadValues(path, Cities);
Map = GenerateMap();
int startIndex = 0;
int endIndex = 0;
List <City> solution = GenerateRandomSolution();
while (temperature > minimTemperature)
{
startIndex = random.Next(0, Cities.Count);
endIndex = random.Next(startIndex, Cities.Count);
List <City> temporarySolution = GetTwoOptNeighbour(startIndex, endIndex, solution);
int solutionTotalDistance = CalculateDistanceBetweenCities(solution);
int temporarySolutionTotalDistance = CalculateDistanceBetweenCities(temporarySolution);
int delta = temporarySolutionTotalDistance - solutionTotalDistance;
if (delta < 0)
{
solution = temporarySolution;
}
else if (random.NextDouble() < Math.Exp(-delta / temperature))
{
solution = temporarySolution;
}
temperature = alpha * temperature;
}
Console.WriteLine("Total distance: " + CalculateDistanceBetweenCities(solution));
return(solution);
}
public List <City> GreedyMethod(string path)
{
Cities = new List <City>();
FileReaderHelper.ReadValues(path, Cities);
Map = GenerateMap();
List <City> solution = new List <City>
{
GenerateRandomSolution().First <City>()
};
while (solution.Count < Cities.Count - 1)
{
solution.Add(GetNearestNeighbourCity(solution.Last <City>(), solution));
}
Console.WriteLine("Total distance: " + CalculateDistanceBetweenCities(solution));
return(solution);
}
public List <City> TwoOptMethod(string path)
{
Cities = new List <City>();
FileReaderHelper.ReadValues(path, Cities);
Map = GenerateMap();
List <City> solution = GenerateRandomSolution();
int firstDistance = CalculateDistanceBetweenCities(solution);
int iterations = 0;
int initialDistance = 0;
int newDistance = 0;
int startIndex = 0;
int endIndex = 0;
List <City> newSolution = new List <City>(solution);
bool MoreTransfomations = true;
while (iterations < 1000)
{
newSolution = new List <City>(solution);
initialDistance = CalculateDistanceBetweenCities(solution);
newDistance = 0;
startIndex = random.Next(0, Cities.Count);
endIndex = random.Next(startIndex, Cities.Count);
for (int i = startIndex; i <= endIndex; i++)
{
City temporary = newSolution[i];
newSolution[i] = newSolution[endIndex];
newSolution[endIndex] = temporary;
endIndex--;
}
newDistance = CalculateDistanceBetweenCities(newSolution);
if (newDistance < initialDistance)
{
solution = newSolution;
iterations = 0;
}
else
{
iterations++;
}
}
Console.WriteLine("Initial distance: " + firstDistance);
Console.WriteLine("Final distance: " + newDistance);
return(newSolution);
}
