public void Generate(List<Task> remainingTasks, int nbTasksInSequence, TaskSequence sequence)
{
var orderedTasks = new List<Task>(nbTasksInSequence);
if (nbTasksInSequence > remainingTasks.Count)
{
throw new Exception("Not enough tasks to generate the specified sequence length");
}
if (remainingTasks.Count > 0)
{
var task = FindAlmostNearestTask(null, remainingTasks, 1.0);
remainingTasks.Remove(task);
orderedTasks.Add(task);
if (remainingTasks.Count > 0)
{
task = FindAlmostNearestTask(task, remainingTasks, 1.0);
remainingTasks.Remove(task);
orderedTasks.Add(task);
orderedTasks.Add(null);
for (int t = 0; t < nbTasksInSequence - 2; t++)
{
int minCost = Int32.MaxValue;
Task minTask = null;
int minInsertPos = -1;
for (int t1 = 0; t1 < orderedTasks.Count - 1; t1++)
{
int cost = FindCheapestInsert(orderedTasks[t1], orderedTasks[t1 + 1], remainingTasks, out task);
if (cost < minCost)
{
minCost = cost;
minTask = task;
minInsertPos = t1;
}
}
remainingTasks.Remove(minTask);
orderedTasks.Insert(minInsertPos + 1, minTask);
}
orderedTasks.RemoveAt(orderedTasks.Count - 1);
}
}
sequence.Tasks = orderedTasks;
}
public TaskSequence Generate(List<Task> remainingTasks, int nbTasksInSequence, Worker worker)
{
var sequence = new TaskSequence{ Worker = worker};
Generate(remainingTasks, nbTasksInSequence, sequence);
return sequence;
}
private void ComputeEdgeRecombinaisonCrossover(TaskSequence p1, TaskSequence p2)
{
// use the Edge recombination operator
// see: http://en.wikipedia.org/wiki/Edge_recombination_operator
//_rand = new Random(11);
for (int t = 0; t < TaskSequencer.GetOriginalTasks().Count; t++)
{
for (int t2 = 0; t2 < TaskSequencer.GetOriginalTasks().Count; t2++)
{
_crossoverTaskNeighborMatrix[t][t2] = false;
}
_crossoverAddedTasks[t] = false;
_crossoverTaskNeighborCount[t] = 0;
_crossoverTaskNeighbors[t][0] = null;
_crossoverTaskNeighbors[t][1] = null;
_crossoverTaskNeighbors[t][2] = null;
_crossoverTaskNeighbors[t][3] = null;
}
Tasks.Clear();
AddNeighborsToCrossoverList(p1);
AddNeighborsToCrossoverList(p2);
Task task = null;
if (_rand.Next(2) == 0)
{
task = p1.Tasks[0];
}
else
{
task = p2.Tasks[0];
}
for (int i = 0; i < TaskSequencer.GetOriginalTasks().Count; i++)
{
Tasks.Add(task);
_crossoverAddedTasks[task.UserId] = true;
int nbNeighbors = _crossoverTaskNeighborCount[task.UserId];
if (nbNeighbors > 0)
{
// find the neighbor with the fewest neighbors...
Task minTask = null;
int minTaskNeighbors = 99999;
// remove the task from its neighbors...
for (int t = 0; t < 4; t++)
{
Task neighbor = _crossoverTaskNeighbors[task.UserId][t];
if (neighbor != null && _crossoverTaskNeighborMatrix[task.UserId][neighbor.UserId])
{
_crossoverTaskNeighborMatrix[neighbor.UserId][task.UserId] = false;
_crossoverTaskNeighborMatrix[task.UserId][neighbor.UserId] = false;
_crossoverTaskNeighborCount[neighbor.UserId]--;
if (_crossoverTaskNeighborCount[neighbor.UserId] < minTaskNeighbors ||
(_crossoverTaskNeighborCount[neighbor.UserId] == minTaskNeighbors &&
_rand.Next(2) == 0))
{
minTask = neighbor;
minTaskNeighbors = _crossoverTaskNeighborCount[neighbor.UserId];
}
}
}
task = minTask;
if (task == null)
{
throw new Exception("null task");
}
}
else
{
// find a task not already added...
for (int notAddedTaskIndex = 0;
notAddedTaskIndex < TaskSequencer.GetOriginalTasks().Count;
notAddedTaskIndex++)
{
if (_crossoverAddedTasks[notAddedTaskIndex] == false)
{
task = TaskSequencer.GetOriginalTasks()[notAddedTaskIndex];
if (task == null)
{
throw new Exception("null task");
}
break;
}
}
}
}
UpdateFitness();
}
private void AddNeighborsToCrossoverList(TaskSequence sequence)
{
Task prevTask = null;
foreach (Task task in sequence.Tasks)
{
if (prevTask != null)
{
if (_crossoverTaskNeighborMatrix[task.UserId][prevTask.UserId] == false)
{
_crossoverTaskNeighborMatrix[task.UserId][prevTask.UserId] = true;
_crossoverTaskNeighbors[task.UserId][_crossoverTaskNeighborCount[task.UserId]] = prevTask;
_crossoverTaskNeighborCount[task.UserId]++;
}
if (_crossoverTaskNeighborMatrix[prevTask.UserId][task.UserId] == false)
{
_crossoverTaskNeighborMatrix[prevTask.UserId][task.UserId] = true;
_crossoverTaskNeighbors[prevTask.UserId][_crossoverTaskNeighborCount[prevTask.UserId]] = task;
_crossoverTaskNeighborCount[prevTask.UserId]++;
}
}
prevTask = task;
}
}
