Examples with Neighbour org.cpsolver.ifs.model.Neighbour used on opensource projects

Example 1 with Neighbour

use of org.cpsolver.ifs.model.Neighbour in project cpsolver by UniTime.

the class ExamColoringConstruction method selectNeighbour.

@Override
public Neighbour<Exam, ExamPlacement> selectNeighbour(final Solution<Exam, ExamPlacement> solution) {
    ExamModel model = (ExamModel) solution.getModel();
    // if (!model.assignedVariables().isEmpty()) return null;
    final HashMap<Exam, Vertex> vertices = new HashMap<Exam, Vertex>();
    for (Exam x : model.variables()) {
        vertices.put(x, new Vertex(x));
    }
    for (ExamStudent s : model.getStudents()) {
        for (Exam x : s.variables()) {
            for (Exam y : s.variables()) {
                if (!x.equals(y)) {
                    vertices.get(x).neighbors().add(vertices.get(y));
                    vertices.get(y).neighbors().add(vertices.get(x));
                }
            }
        }
    }
    for (ExamInstructor i : model.getInstructors()) {
        for (Exam x : i.variables()) {
            for (Exam y : i.variables()) {
                if (!x.equals(y)) {
                    vertices.get(x).neighbors().add(vertices.get(y));
                    vertices.get(y).neighbors().add(vertices.get(x));
                }
            }
        }
    }
    iProgress.setPhase("Graph coloring-based construction", vertices.size());
    iProgress.info("Looking for a conflict-free assignment using " + model.getPeriods().size() + " periods.");
    iT0 = JProf.currentTimeSec();
    iTimeLimitReached = false;
    if (iMode.isGreedy()) {
        iProgress.info("Using greedy heuristics only (no backtracking)...");
    } else if (backTrack(solution, 0, (iMode.isRedundant() ? null : new HashSet<Integer>()), vertices.values())) {
        iProgress.info("Success!");
    } else if (iTimeLimitReached) {
        iProgress.info("There was no conflict-free schedule found during the given time.");
    } else if (iSolver.isStop()) {
        iProgress.info("Solver was stopped.");
    } else {
        if (iMode.isRedundant())
            iProgress.info("There is no conflict-free schedule!");
        else
            iProgress.info("Conflict-free schedule not found.");
    }
    if (iMode.isConstraintCheck())
        solution.restoreBest();
    HashSet<Vertex> remaning = new HashSet<Vertex>();
    for (Vertex v : vertices.values()) if (v.color() < 0)
        remaning.add(v);
    remaining: while (!remaning.isEmpty()) {
        Vertex vertex = null;
        for (Vertex v : remaning) if (vertex == null || v.compareTo(vertex) < 0)
            vertex = v;
        remaning.remove(vertex);
        for (int color : vertex.domain()) if (vertex.colorize(solution.getAssignment(), color))
            continue remaining;
    }
    if (!iMode.isConstraintCheck()) {
        return new Neighbour<Exam, ExamPlacement>() {

            @Override
            public void assign(Assignment<Exam, ExamPlacement> assignment, long iteration) {
                iProgress.info("Using graph coloring solution ...");
                for (Vertex vertex : new TreeSet<Vertex>(vertices.values())) {
                    ExamPeriodPlacement period = vertex.period();
                    if (period == null || !vertex.exam().checkDistributionConstraints(assignment, period))
                        continue;
                    Set<ExamRoomPlacement> rooms = findRooms(assignment, vertex.exam(), period);
                    if (rooms == null)
                        continue;
                    assignment.assign(iteration, new ExamPlacement(vertex.exam(), period, rooms));
                }
                HashSet<Vertex> unassigned = new HashSet<Vertex>();
                for (Vertex vertex : vertices.values()) {
                    if (assignment.getValue(vertex.exam()) == null) {
                        unassigned.add(vertex);
                        vertex.colorize(assignment, -1);
                    }
                }
                solution.saveBest();
                iProgress.info("Extending ...");
                unassigned: while (!unassigned.isEmpty()) {
                    Vertex vertex = null;
                    for (Vertex v : unassigned) if (vertex == null || v.compareTo(vertex) < 0)
                        vertex = v;
                    unassigned.remove(vertex);
                    for (int color : vertex.domain()) {
                        if (!vertex.colorize(assignment, color))
                            continue;
                        ExamPeriodPlacement period = vertex.period(color);
                        if (period == null || !vertex.exam().checkDistributionConstraints(assignment, period))
                            continue;
                        Set<ExamRoomPlacement> rooms = findRooms(assignment, vertex.exam(), period);
                        if (rooms == null)
                            continue;
                        assignment.assign(iteration, new ExamPlacement(vertex.exam(), period, rooms));
                        continue unassigned;
                    }
                    vertex.colorize(assignment, -1);
                }
                solution.saveBest();
                iProgress.info("Construction done.");
            }

            @Override
            public double value(Assignment<Exam, ExamPlacement> assignment) {
                return 0;
            }

            @Override
            public Map<Exam, ExamPlacement> assignments() {
                throw new UnsupportedOperationException();
            }
        };
    }
    return null;
}