private static int Pivot(ArrayList array, int lower, int upper)
{
// Pivot with first element
int left = lower + 1;
object pivot = array[lower];
int right = upper;
// Partition array elements
while (left <= right)
{
// Find item out of place
while ((left <= right) && (comparer.Compare(array[left], pivot) <= 0))
{
++left;
}
while ((left <= right) && (comparer.Compare(array[right], pivot) > 0))
{
--right;
}
// Swap values if necessary
if (left < right)
{
swapper.Swap(array, left, right);
++left;
--right;
}
}
// Move pivot element
swapper.Swap(array, lower, right);
return(right);
}
public Log Compute(Graph graph)
{
TerminateCondition Terminate = this.terminateStrategy();
int numberOfRoutes = 0;
//Initalise population
for (int i = 0; i < population.Length; i++)
{
population[i] = InitalisationStrategy.Initalise(graph.nodes);
}
Route?bestRoute = default;
Stopwatch timer = new Stopwatch();
timer.Start();
int generationCounter = 0;
int itterationCounter = 0;
while (!Terminate())
{
Route[] parents = selectionStrategy.Select(population, 20, step);
//Recombine pairs of parents
Route[] children = Recombine(parents, (int)eliteism * parents.Length);
//Mutate the resulting offsprint
for (int i = 0; i < children.Length; i++)
{
if (random.NextDouble() < mutationRate)
{
children[i] = swap.Swap(children[i]);
}
numberOfRoutes++;
bestRoute = bestRoute == null ? children[i] : step.CostP(children[i], bestRoute);
population[generationCounter] = children[i];
generationCounter = (generationCounter + 1) % population.Length;
}
OnItterationComplete?.Invoke(this, new Log()
{
numberOfRoutesEvaluated = numberOfRoutes,
iteration = itterationCounter,
bestRouteCost = bestRoute != null ? bestRoute.Distance() : float.MaxValue,
bestRoute = bestRoute != null ? bestRoute.ToString() : string.Empty,
timeToCompute = timer.ElapsedMilliseconds,
});
}
timer.Stop();
return(new Log()
{
timeToCompute = timer.ElapsedMilliseconds,
numberOfRoutesEvaluated = numberOfRoutes,
iteration = itterationCounter,
bestRouteCost = bestRoute != null?bestRoute.Distance() : float.MaxValue,
bestRoute = bestRoute != null?bestRoute.ToString() : string.Empty,
});
}