private Set<Integer> getPossibleNumberOfDepartures(
Set<Integer> unvisitedDays,
HashMap<Integer, Set<Integer>> individualVesselDeparturePatterns,
int alreadyVisitedDaysAvailable) {
int maxDeparturesInPattern =
Collections.max(
problemData
.getVesselDeparturePatterns()
.keySet()); // the maximum number of departures found in any vessel pattern
int minimumNumberOfDepartures =
Math.max(
0,
maxDeparturesInPattern
- alreadyVisitedDaysAvailable); // e.g. if the patterns have max 3 visits and only 1
// day that is already visited can be a part of the
// pattern, the minimum pattern size is 2 (since
// there are 2 unvisited days)
Set<Integer> allNumberOfDepartures = problemData.getVesselDeparturePatterns().keySet();
Set<Integer> possibleNumberOfDepartures = new HashSet<Integer>();
for (Integer numberOfDepartures : allNumberOfDepartures) {
if (numberOfDepartures >= minimumNumberOfDepartures) {
possibleNumberOfDepartures.add(numberOfDepartures);
}
}
return possibleNumberOfDepartures;
}
private HashMap<Integer, Set<Integer>> createVesselDepartureChromosome(
HashMap<Integer, Set<Integer>> installationDepartureChromosome) {
HashMap<Integer, Set<Integer>> individualVesselDeparturePatterns =
new HashMap<Integer, Set<Integer>>();
Set<Integer> daysWithDeparture =
getDaysWithDeparture(
installationDepartureChromosome); // get all days that installations require a departure
for (Vessel vessel :
problemData
.getVessels()) { // for each vessel, choose a random vessel pattern that fits with the
// installationDepartureChromosome
Set<Integer> randomVesselDeparturePattern =
pickRandomVesselDeparturePattern(daysWithDeparture, individualVesselDeparturePatterns);
if (randomVesselDeparturePattern == null) { // workaround until a smarter heuristic is created
numberOfPatternRestarts++;
return createVesselDepartureChromosome(installationDepartureChromosome);
}
individualVesselDeparturePatterns.put(vessel.getNumber(), randomVesselDeparturePattern);
}
if (isDepotConstraintViolated(individualVesselDeparturePatterns)) {
numberOfDepotRestarts++;
return createVesselDepartureChromosome(installationDepartureChromosome);
}
return individualVesselDeparturePatterns;
}
private HashMap<Integer, Set<Integer>> createInstallationDepartureChromosome() {
HashMap<Integer, Set<Integer>> individualInstallationDeparturePatterns =
new HashMap<Integer, Set<Integer>>();
for (Installation installation :
problemData
.getCustomerInstallations()) { // for each installation, choose a random installation
// pattern based on the frequency
Set<Set<Integer>> possibleInstallationDeparturePatterns =
problemData.getInstallationDeparturePatterns().get(installation.getFrequency());
Set<Integer> randomInstallationDeparturePattern =
Utilities.pickRandomElementFromSet(possibleInstallationDeparturePatterns);
individualInstallationDeparturePatterns.put(
installation.getNumber(), randomInstallationDeparturePattern);
}
return individualInstallationDeparturePatterns;
}
private int getAlreadyVisitedDaysAvailable(
HashMap<Integer, Set<Integer>> individualVesselDeparturePatterns,
Set<Integer> unvisitedDays) {
int vesselsLeft =
problemData.getVessels().size()
- individualVesselDeparturePatterns.keySet().size(); // number of unchartered vessels
int maxDeparturesInPattern =
Collections.max(
problemData
.getVesselDeparturePatterns()
.keySet()); // the maximum number of departures found in any vessel pattern
int alreadyVisitedDaysAvailable =
(vesselsLeft * maxDeparturesInPattern
- unvisitedDays
.size()); // if there is 1 unchartered vessel and the patterns have maximum 3
// departures and there are 2 days without departures, at most 1*3 - 2 = 1
// day that already has a departure can be part of the new pattern
return alreadyVisitedDaysAvailable;
}
private HashMap<Integer, HashMap<Integer, ArrayList<Integer>>> createGiantTourChromosome(
HashMap<Integer, Set<Integer>> installationDepartureChromosome,
HashMap<Integer, Set<Integer>> vesselDepartureChromosome) {
HashMap<Integer, Set<Integer>> reversedInstallationChromosome =
Utilities.getReversedHashMap(
installationDepartureChromosome); // the key is a period/day and the Set<Integer> is a
// set of installation numbers
HashMap<Integer, Set<Integer>> reversedVesselChromosome =
Utilities.getReversedHashMap(
vesselDepartureChromosome); // the key is a period/day, and the Set<Integer> is a set of
// vessel numbers
int nDays = problemData.getLengthOfPlanningPeriod();
int nVessels = problemData.getVessels().size();
// initializing
HashMap<Integer, HashMap<Integer, ArrayList<Integer>>> giantTourChromosome =
GenotypeHGS.generateEmptyGiantTourChromosome(nDays, nVessels);
// allocating
for (Integer day : reversedInstallationChromosome.keySet()) {
Set<Integer> installationsToAllocate = reversedInstallationChromosome.get(day);
Set<Integer> availableVessels = reversedVesselChromosome.get(day);
HashMap<Integer, ArrayList<Integer>> vesselAllocations = giantTourChromosome.get(day);
for (Integer installation : installationsToAllocate) {
Integer randomVessel = Utilities.pickRandomElementFromSet(availableVessels);
ArrayList<Integer> existingInstallations = vesselAllocations.get(randomVessel);
existingInstallations.add(installation);
vesselAllocations.put(randomVessel, existingInstallations);
}
giantTourChromosome.put(day, vesselAllocations);
}
// shuffle sequence of visits
for (Integer day : giantTourChromosome.keySet()) {
for (Integer vessel : giantTourChromosome.get(day).keySet()) {
ArrayList<Integer> installationsToVisit = giantTourChromosome.get(day).get(vessel);
Collections.shuffle(installationsToVisit);
}
}
return giantTourChromosome;
}
private Set<Integer> pickRandomVesselDeparturePattern(
Set<Integer> daysWithDeparture,
HashMap<Integer, Set<Integer>> individualVesselDeparturePatterns) {
Set<Integer> unvisitedDays =
getUnvisitedDays(
daysWithDeparture,
individualVesselDeparturePatterns); // the set of days that installations require a
// departure and no vessel depart on
int alreadyVisitedDaysAvailable =
getAlreadyVisitedDaysAvailable(
individualVesselDeparturePatterns,
unvisitedDays); // the number of days that already have visits that the vessel pattern
// can contain
Set<Integer> possibleNumberOfDepartures =
getPossibleNumberOfDepartures(
unvisitedDays,
individualVesselDeparturePatterns,
alreadyVisitedDaysAvailable); // the set of number of departures that a valid vessel
// pattern can have, e.g. if it's the last vessel and
// there are still 3 unvisited days, the vessel pattern
// must have 3 depatures
int unvisitedDaysThatNeedsVisit = Collections.min(possibleNumberOfDepartures);
int numberOfVesselDepartures =
Utilities.pickRandomElementFromSet(
possibleNumberOfDepartures); // select a random number from the set of possible number
// of departures
Set<Set<Integer>> allPatternsForNumberOfDepartures =
problemData.getVesselDeparturePatterns().get(numberOfVesselDepartures);
Set<Set<Integer>> possibleVesselDeparturePatterns =
getPossibleVesselPatterns(
allPatternsForNumberOfDepartures,
individualVesselDeparturePatterns,
unvisitedDays,
unvisitedDaysThatNeedsVisit); // get all vessel patterns with the selected number of
// departures that visit enough of the unvisited
// installations, e.g. if it's the last vessel the pattern
// has to visit all unvisited installations
if (possibleVesselDeparturePatterns.size()
== 0) { // workaround until a smarter heuristic is fixed
System.out.println("No possible patterns, start over!");
return null;
}
return Utilities.pickRandomElementFromSet(possibleVesselDeparturePatterns);
}
private boolean isDepotConstraintViolated(
HashMap<Integer, Set<Integer>> individualVesselDeparturePatterns) {
HashMap<Integer, Integer> departureCount = new HashMap<Integer, Integer>();
for (int vesselNumber : individualVesselDeparturePatterns.keySet()) {
Set<Integer> selectedPattern = individualVesselDeparturePatterns.get(vesselNumber);
for (Integer day : selectedPattern) {
Integer dayCount = departureCount.get(day);
if (dayCount == null) {
departureCount.put(day, 1);
} else {
departureCount.put(day, dayCount + 1);
}
}
}
HashMap<Integer, Integer> depotCapacity = problemData.getDepotCapacity();
for (Integer day : departureCount.keySet()) {
if (departureCount.get(day) > depotCapacity.get(day)) {
return true;
}
}
return false;
}