private int findDist(UniverseGraph.SystemId source, UniverseGraph.SystemId dest)
{
open = new PriorityQueue<int, Node>();
closed = new HashSet<UniverseGraph.SystemId>();
open.push(0, new Node(null, source));
Node current = null;
int currentPriority = 0;
while ((open.count() > 0) && (closed.Count < maxClosedSize))
{
//pop top
PriorityQueue<int, Node>.Pair head = open.pop();
current = head.value;
currentPriority = head.key;
//check if we've reached the destination
if (current.sysid.id == dest.id)
return currentPriority*-1;
if (!closed.Contains(current.sysid))
{
//mark that we've already expanded it
closed.Add(current.sysid);
//expand it
foreach (UniverseGraph.SystemId neighbour in graph.systemEdges[current.sysid])
{
if (graph.idToInfo[neighbour].security > minSecurity)
{
Node nNode = new Node(current, neighbour);
//decrease priority by number of jumps so far - ie breadth first search
//some a* like heuristic would be nice....
int nPriority = currentPriority - 1;
open.push(nPriority, nNode);
}
}
}
}
//some kind of failure state - either no path, or seach size exceeded (too far)
return -1;
}
public PlannerState computePlan(double initialWallet,
double initialCargoCap,
string initialSystemName,
int maxJumps)
{
//reset lists
this.open = new PriorityQueue<double, PlannerState>();
this.closed = new SpaceTimeProfitCache();
//compute a heuristic for the max possible profit rate
double bestProfitRate = 0.0;
double candidateProfitRate = 0.0;
foreach(List<TradeRouteMiner.Route> lr in trm.systemRoutes.Values)
{
foreach (TradeRouteMiner.Route r in lr)
{
candidateProfitRate = Math.Min(r.profitDensityRate * initialCargoCap, r.bulkProfitRate);
bestProfitRate = Math.Max(bestProfitRate, candidateProfitRate);
}
}
//hence we can order PlannerStates by state.wallet + bestProfitRate*(maxJumps-state.jumpsElapsed)
//and use a*
Console.WriteLine("best profit rate heuristic : " + bestProfitRate);
//establish the initial state
PlannerState initialState = new PlannerState(initialCargoCap, initialWallet, initialSystemName);
open.push(getPriority(initialState, bestProfitRate, maxJumps), initialState);
//stat tracking
int statTouchedStates = 0;
int statAddedStates = 0;
int progressUpdateFrequency = 10000;
//use a* to find the optimal plan up to max specified number of jumps
while (open.count() > 0)
{
PriorityQueue<double, PlannerState>.Pair pair = open.pop();
++statTouchedStates;
//Console.WriteLine("!tradeplanner : open count = " + open.count()
// + "; jumpsElapsed = " + pair.value.jumpsElapsed
// + "; priority = "+pair.key);
if (statTouchedStates % progressUpdateFrequency == 0)
{
//display search progress update for user
Console.WriteLine("TradePlanner Stats : WORKING");
Console.WriteLine("\ttouched states = " + statTouchedStates);
Console.WriteLine("\tadded states = " + statAddedStates);
Console.WriteLine("\tstates in open list = " + open.count());
Console.WriteLine("\thighest priority = " + pair.key);
Console.WriteLine("\trecent jumps elapsed = " + pair.value.jumpsElapsed);
}
//check for stopping condition
if (pair.value.jumpsElapsed >= maxJumps)
{
Console.WriteLine("TradePlanner Stats : FINISHED!");
Console.WriteLine("\ttouched states = " + statTouchedStates);
Console.WriteLine("\tadded states = " + statAddedStates);
Console.WriteLine("\tstates in open list = " + open.count());
Console.WriteLine("\thighest priority = " + pair.key);
Console.WriteLine("\trecent jumps elapsed = " + pair.value.jumpsElapsed);
return pair.value;
}
//otherwise, expand planner state and pop children back into the open list
foreach (PlannerState childState in pair.value.expandStates(trm, graph))
{
//only add the child state if it gives us an improved profit upon what we've already seen
if(closed.achievesBetterProfit(childState.sysName, childState.jumpsElapsed, childState.wallet))
{
open.push(getPriority(childState,bestProfitRate, maxJumps), childState);
++statAddedStates;
}
}
}
//we've failed, for some reason, to find a plan
return null;
}
