public void GenerateChildren(ref List <NodeState> queue, ref int MaxNodeStateAmount, ref int BSSFupdates, ref int TotalNodeStates, ref int TotalNodeStatesPrunned, int startCity)
{
int cityCount = Cities.Length;
//Get the first node in the priority
NodeState currentNodeState = DeletePriorityNode(ref queue);
//If the currentNodeState should be prunned
if (currentNodeState.GetLowerBound() >= bssf.costOfRoute())
{
currentNodeState = PruneTheQueue(ref queue, currentNodeState, ref TotalNodeStatesPrunned);
}
//Generate a child for each city the currentNodeState can go to.
for (int i = 0; i < cityCount; i++)
{
if (!currentNodeState.AlreadyVisited(i))
{
//Make a child
NodeState child = MakeChild(ref currentNodeState, i);
child.ReduceMatrixAndUpdateLowerBound(cityCount);
// Add to node states because a child was generated
TotalNodeStates++;
//If LB is less BSSF then add to queue, TNS++
if (child.GetLowerBound() < bssf.costOfRoute())
{
//Before adding to the queue, see if you have a new BSSF
if (BetterBSSFExists(ref child, startCity))
{
bssf = new TSPSolution(child.GetRoute());
BSSFupdates++;
}
else
{
//add node to the queue
if (!child.HasVisitedAllCities())
{
//Add
AddNodeToPriorityQueue(ref queue, child);
}
}
}
else
{
//Prune. We don't need to even visit it.
TotalNodeStatesPrunned++;
}
}
}
//Check the MaxNodeStates
CheckQueueSize(ref MaxNodeStateAmount, queue.Count - 1);
}
public bool BetterBSSFExists(ref NodeState node, int startCity)
{
if (node.HasVisitedAllCities())
{
//check if it can go back to it's first city
int currentCity = node.GetLastCityInRouteIndex();
double[,] nodeMatrix = node.GetMatrix();
if (nodeMatrix[startCity, currentCity] != Double.PositiveInfinity)
{
//We can go back.
return(true);
}
else
{
return(false);
}
}
else
{
return(false);
}
}