public void doAlgorithm(Graph busGraph, AllPairsShortestPath allPairsShortestPath) {
TimeStepper.step();
this.busGraph = busGraph;
this.allPairsShortestPath = allPairsShortestPath;
if (count < 500) {
count++;
System.out.println("TimeStep " + count);
BusCentralDatabase.printStateOfWorld();
}
if (BusCentralDatabase.getBusesInTheWorld().size() > 0) {
// Firstly any bus that is at a stop in which a passenger could be dropped off should do so
dropOffPassengers();
// If there are unallocated passengers then we may need to change the paths that buses are
// currently moving along
if (BusCentralDatabase.getUnallocatedPassengers().size() > 0) {
dynamicReroutingAndPassengerAllocation();
}
// Pick up passenger if bus is at destination
pickupPassengers();
// Tell all the buses to move along their routes to the next location
incrimentBuses();
}
}
private void incrimentBuses() {
for (int i = 0; i < BusCentralDatabase.getBusesInTheWorld().size(); i++) {
Bus bus = BusCentralDatabase.getBusesInTheWorld().get(i);
bus.moveAlongPath();
}
}
private void dropOffPassengers() {
ArrayList<Bus> allBuses = BusCentralDatabase.getBusesInTheWorld();
for (int i = 0; i < allBuses.size(); i++) {
Bus bus = allBuses.get(i);
if (bus.getCostToNextStop() == 0) {
bus.dropOffPassengers();
}
}
}
private void pickupPassengers() {
ArrayList<Bus> busesInTheWorld = BusCentralDatabase.getBusesInTheWorld();
for (int i = 0; i < busesInTheWorld.size(); i++) {
Bus bus = busesInTheWorld.get(i);
if (bus.getCostToNextStop() == 0) {
bus.pickupPassengers(TimeStepper.getTime());
}
}
}
// Sets the paths for all the buses.
private void dynamicReroutingAndPassengerAllocation() {
HashMap<Bus, LinkedList<Vertex>> BusesAndPotentialPaths =
new HashMap<Bus, LinkedList<Vertex>>();
/**
* We need to decide how to reroute our buses when we have new passengers added to the world.
* Simply perform this computation over all of the buses and store the total cost of doing that.
*/
for (int q = 0; q < BusCentralDatabase.getBusesInTheWorld().size(); q++) {
Bus firstBus = BusCentralDatabase.getBusesInTheWorld().get(q);
// For the rootNode
Vertex rootNode = firstBus.getCurrentStop();
// If the bus is between stops then the rootNode will be the next node
if (firstBus.getCostToNextStop() != 0) {
rootNode = firstBus.getPath().get(1);
}
// Getting the list of pickups. These are the stops the will be part of the picking up of a
// passenger
ArrayList<Passenger> pickups =
(ArrayList<Passenger>) BusCentralDatabase.getUnallocatedPassengers().clone();
pickups.addAll(firstBus.getAssignedPassengers());
ArrayList<Vertex> pickupStops = new ArrayList<Vertex>();
for (int i = 0; i < pickups.size(); i++) {
if (!pickupStops.contains(pickups.get(i).getStartingStop())) {
pickupStops.add(pickups.get(i).getStartingStop());
}
}
// Getting the list of dropoff. These include the destination of passengers currently on the
// bus and passengers
ArrayList<Vertex> dropoffs = new ArrayList<Vertex>();
ArrayList<Passenger> busPassengers = firstBus.getPassengersOnBus();
for (int j = 0; j < busPassengers.size(); j++) {
if (!dropoffs.contains(busPassengers.get(j).getDestinationStop())) {
dropoffs.add(busPassengers.get(j).getDestinationStop());
}
}
for (int i = 0; i < pickups.size(); i++) {
if (!dropoffs.contains(pickups.get(i).getDestinationStop())) {
dropoffs.add(pickups.get(i).getDestinationStop());
}
}
// This should have added all pickup and dropoff stops and the root. Now must pair the pickups
// and dropoffs
ArrayList<ArrayList<Vertex>> pairs = new ArrayList<ArrayList<Vertex>>();
for (int i = 0; i < pickups.size(); i++) {
Vertex start = pickups.get(i).getStartingStop();
Vertex finish = pickups.get(i).getDestinationStop();
ArrayList<Vertex> tuple = new ArrayList<Vertex>();
tuple.add(start);
tuple.add(finish);
pairs.add(tuple);
}
LinkedList<Vertex> optimalPath = bestPath(rootNode, pickupStops, dropoffs, pairs);
// You can't just do this because the bus may be between some stops
if (firstBus.getCostToNextStop() > 0) {
LinkedList<Vertex> path = new LinkedList<Vertex>();
path.add(firstBus.getCurrentStop());
path.addAll(optimalPath);
optimalPath = path;
}
BusesAndPotentialPaths.put(firstBus, optimalPath);
}
int totalSystemCost = 0;
for (int i = 0; i < BusCentralDatabase.getBusesInTheWorld().size(); i++) {
Bus bus = BusCentralDatabase.getBusesInTheWorld().get(i);
LinkedList<Vertex> path = (LinkedList<Vertex>) bus.getPath().clone();
int pathCost = 0;
if (bus.getCostToNextStop() > 0) {
path.remove(0);
pathCost = sizeOfPath(path);
pathCost += bus.getCostToNextStop();
} else {
pathCost = sizeOfPath(path);
}
if (pathCost > totalSystemCost) {
totalSystemCost = pathCost;
}
}
HashMap BusesAndCosts = new HashMap<Bus, Integer>();
for (int i = 0; i < BusesAndPotentialPaths.size(); i++) {
Bus bus = BusCentralDatabase.getBusesInTheWorld().get(i);
int pathCost = sizeOfPath(BusesAndPotentialPaths.get(bus));
if (bus.getCostToNextStop() > 0) {
LinkedList<Vertex> path = (LinkedList<Vertex>) BusesAndPotentialPaths.get(bus).clone();
path.remove(0);
pathCost = sizeOfPath(path);
pathCost += bus.getCostToNextStop();
}
BusesAndCosts.put(bus, pathCost);
}
int min = Collections.min(BusesAndCosts.values());
Iterator it = BusesAndCosts.entrySet().iterator();
Bus bus = null;
while (it.hasNext()) {
Map.Entry<Bus, Integer> pairs = (Map.Entry<Bus, Integer>) it.next();
if (pairs.getValue() == min) {
bus = pairs.getKey();
break;
}
}
bus.setPath(BusesAndPotentialPaths.get(bus));
int numberOfPickups = BusCentralDatabase.getUnallocatedPassengers().size();
for (int i = 0; i < numberOfPickups; i++) {
bus.assignPassenger(BusCentralDatabase.getUnallocatedPassengers().get(0));
}
// System.out.println("TEST");
}