Examples with SctAssignment org.cpsolver.studentsct.model.SctAssignment used on opensource projects

Example 1 with SctAssignment

use of org.cpsolver.studentsct.model.SctAssignment in project cpsolver by UniTime.

the class OriginalStudentWeights method main.

/**
     * Test case -- run to see the weights for a few courses
     * @param args program arguments
     */
public static void main(String[] args) {
    OriginalStudentWeights pw = new OriginalStudentWeights(new DataProperties());
    DecimalFormat df = new DecimalFormat("0.000");
    Student s = new Student(0l);
    new CourseRequest(1l, 0, false, s, ToolBox.toList(new Course(1, "A", "1", new Offering(0, "A")), new Course(1, "A", "2", new Offering(0, "A")), new Course(1, "A", "3", new Offering(0, "A"))), false, null);
    new CourseRequest(2l, 1, false, s, ToolBox.toList(new Course(1, "B", "1", new Offering(0, "B")), new Course(1, "B", "2", new Offering(0, "B")), new Course(1, "B", "3", new Offering(0, "B"))), false, null);
    new CourseRequest(3l, 2, false, s, ToolBox.toList(new Course(1, "C", "1", new Offering(0, "C")), new Course(1, "C", "2", new Offering(0, "C")), new Course(1, "C", "3", new Offering(0, "C"))), false, null);
    new CourseRequest(4l, 3, false, s, ToolBox.toList(new Course(1, "D", "1", new Offering(0, "D")), new Course(1, "D", "2", new Offering(0, "D")), new Course(1, "D", "3", new Offering(0, "D"))), false, null);
    new CourseRequest(5l, 4, false, s, ToolBox.toList(new Course(1, "E", "1", new Offering(0, "E")), new Course(1, "E", "2", new Offering(0, "E")), new Course(1, "E", "3", new Offering(0, "E"))), false, null);
    new CourseRequest(6l, 5, true, s, ToolBox.toList(new Course(1, "F", "1", new Offering(0, "F")), new Course(1, "F", "2", new Offering(0, "F")), new Course(1, "F", "3", new Offering(0, "F"))), false, null);
    new CourseRequest(7l, 6, true, s, ToolBox.toList(new Course(1, "G", "1", new Offering(0, "G")), new Course(1, "G", "2", new Offering(0, "G")), new Course(1, "G", "3", new Offering(0, "G"))), false, null);
    Assignment<Request, Enrollment> assignment = new DefaultSingleAssignment<Request, Enrollment>();
    Placement p = new Placement(null, new TimeLocation(1, 90, 12, 0, 0, null, null, new BitSet(), 10), new ArrayList<RoomLocation>());
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            w[i] = pw.getWeight(assignment, e, null, null);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("With one distance conflict:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<DistanceConflict.Conflict> dc = new HashSet<DistanceConflict.Conflict>();
            dc.add(new DistanceConflict.Conflict(s, e, (Section) sections.iterator().next(), e, (Section) sections.iterator().next()));
            w[i] = pw.getWeight(assignment, e, dc, null);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("With two distance conflicts:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<DistanceConflict.Conflict> dc = new HashSet<DistanceConflict.Conflict>();
            dc.add(new DistanceConflict.Conflict(s, e, (Section) sections.iterator().next(), e, (Section) sections.iterator().next()));
            dc.add(new DistanceConflict.Conflict(s, e, (Section) sections.iterator().next(), e, new Section(1, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null)));
            w[i] = pw.getWeight(assignment, e, dc, null);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("With 25% time overlapping conflicts:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<TimeOverlapsCounter.Conflict> toc = new HashSet<TimeOverlapsCounter.Conflict>();
            toc.add(new TimeOverlapsCounter.Conflict(s, 3, e, sections.iterator().next(), e, sections.iterator().next()));
            w[i] = pw.getWeight(assignment, e, null, toc);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
}

Example 2 with SctAssignment

use of org.cpsolver.studentsct.model.SctAssignment in project cpsolver by UniTime.

the class TimeOverlapsCounter method allConflicts.

/**
     * The set of all conflicts ({@link Conflict} objects) of the given
     * enrollment and other enrollments that are assigned to the same student.
     * @param assignment current assignment
     * @param enrollment given enrollment
     * @return all conflicts of the given enrollment
     */
public Set<Conflict> allConflicts(Assignment<Request, Enrollment> assignment, Enrollment enrollment) {
    Set<Conflict> ret = new HashSet<Conflict>();
    if (enrollment.getRequest() instanceof FreeTimeRequest)
        return ret;
    for (Request request : enrollment.getStudent().getRequests()) {
        if (request.equals(enrollment.getRequest()))
            continue;
        Enrollment other = assignment.getValue(request);
        if (request instanceof FreeTimeRequest) {
            FreeTimeRequest ft = (FreeTimeRequest) request;
            ret.addAll(conflicts(enrollment, ft.createEnrollment()));
            continue;
        } else if (other != null) {
            ret.addAll(conflicts(enrollment, other));
        }
    }
    for (Unavailability unavailability : enrollment.getStudent().getUnavailabilities()) for (SctAssignment section : enrollment.getAssignments()) if (inConflict(section, unavailability))
        ret.add(new Conflict(enrollment.getStudent(), share(section, unavailability), enrollment, section, unavailability.createEnrollment(), unavailability));
    return ret;
}

Example 3 with SctAssignment

use of org.cpsolver.studentsct.model.SctAssignment in project cpsolver by UniTime.

the class InevitableStudentConflicts method enrollment2string.

/**
     * Convert given enrollment to a string (comma separated list of subpart
     * names and time assignments only)
     */
private static String enrollment2string(Enrollment enrollment) {
    StringBuffer sb = new StringBuffer();
    Collection<SctAssignment> assignments = enrollment.getAssignments();
    if (enrollment.isCourseRequest()) {
        assignments = new TreeSet<SctAssignment>(new Comparator<SctAssignment>() {

            @Override
            public int compare(SctAssignment a1, SctAssignment a2) {
                Section s1 = (Section) a1;
                Section s2 = (Section) a2;
                return s1.getSubpart().compareTo(s2.getSubpart());
            }
        });
        assignments.addAll(enrollment.getAssignments());
    }
    for (Iterator<? extends SctAssignment> i = assignments.iterator(); i.hasNext(); ) {
        SctAssignment a = i.next();
        if (a instanceof Section)
            sb.append(((Section) a).getSubpart().getName() + " ");
        if (a.getTime() != null)
            sb.append(a.getTime().getLongName(true));
        if (i.hasNext())
            sb.append(", ");
    }
    return sb.toString();
}

Example 4 with SctAssignment

use of org.cpsolver.studentsct.model.SctAssignment in project cpsolver by UniTime.

the class EqualStudentWeights method main.

/**
     * Test case -- run to see the weights for a few courses
     * @param args program arguments
     */
public static void main(String[] args) {
    EqualStudentWeights pw = new EqualStudentWeights(new DataProperties());
    DecimalFormat df = new DecimalFormat("0.0000");
    Student s = new Student(0l);
    new CourseRequest(1l, 0, false, s, ToolBox.toList(new Course(1, "A", "1", new Offering(0, "A")), new Course(1, "A", "2", new Offering(0, "A")), new Course(1, "A", "3", new Offering(0, "A"))), false, null);
    new CourseRequest(2l, 1, false, s, ToolBox.toList(new Course(1, "B", "1", new Offering(0, "B")), new Course(1, "B", "2", new Offering(0, "B")), new Course(1, "B", "3", new Offering(0, "B"))), false, null);
    new CourseRequest(3l, 2, false, s, ToolBox.toList(new Course(1, "C", "1", new Offering(0, "C")), new Course(1, "C", "2", new Offering(0, "C")), new Course(1, "C", "3", new Offering(0, "C"))), false, null);
    new CourseRequest(5l, 4, false, s, ToolBox.toList(new Course(1, "E", "1", new Offering(0, "E")), new Course(1, "E", "2", new Offering(0, "E")), new Course(1, "E", "3", new Offering(0, "E"))), false, null);
    new CourseRequest(6l, 5, true, s, ToolBox.toList(new Course(1, "F", "1", new Offering(0, "F")), new Course(1, "F", "2", new Offering(0, "F")), new Course(1, "F", "3", new Offering(0, "F"))), false, null);
    new CourseRequest(7l, 6, true, s, ToolBox.toList(new Course(1, "G", "1", new Offering(0, "G")), new Course(1, "G", "2", new Offering(0, "G")), new Course(1, "G", "3", new Offering(0, "G"))), false, null);
    Assignment<Request, Enrollment> assignment = new DefaultSingleAssignment<Request, Enrollment>();
    Placement p = new Placement(null, new TimeLocation(1, 90, 12, 0, 0, null, null, new BitSet(), 10), new ArrayList<RoomLocation>());
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            w[i] = pw.getWeight(assignment, e, null, null);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("With one distance conflict:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<DistanceConflict.Conflict> dc = new HashSet<DistanceConflict.Conflict>();
            dc.add(new DistanceConflict.Conflict(s, e, (Section) sections.iterator().next(), e, (Section) sections.iterator().next()));
            w[i] = pw.getWeight(assignment, e, dc, null);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("With two distance conflicts:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<DistanceConflict.Conflict> dc = new HashSet<DistanceConflict.Conflict>();
            dc.add(new DistanceConflict.Conflict(s, e, (Section) sections.iterator().next(), e, (Section) sections.iterator().next()));
            dc.add(new DistanceConflict.Conflict(s, e, (Section) sections.iterator().next(), e, new Section(1, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null)));
            w[i] = pw.getWeight(assignment, e, dc, null);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("With 25% time overlapping conflict:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<TimeOverlapsCounter.Conflict> toc = new HashSet<TimeOverlapsCounter.Conflict>();
            toc.add(new TimeOverlapsCounter.Conflict(s, 3, e, sections.iterator().next(), e, sections.iterator().next()));
            w[i] = pw.getWeight(assignment, e, null, toc);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("Disbalanced sections (by 2 / 10 students):");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            Subpart x = new Subpart(0, "Lec", "Lec", cfg, null);
            Section a = new Section(0, 10, "x", x, p, null);
            new Section(1, 10, "y", x, p, null);
            sections.add(a);
            a.assigned(assignment, new Enrollment(s.getRequests().get(0), i, cfg, sections, assignment));
            a.assigned(assignment, new Enrollment(s.getRequests().get(0), i, cfg, sections, assignment));
            cfg.getContext(assignment).assigned(assignment, new Enrollment(s.getRequests().get(0), i, cfg, sections, assignment));
            cfg.getContext(assignment).assigned(assignment, new Enrollment(s.getRequests().get(0), i, cfg, sections, assignment));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            w[i] = pw.getWeight(assignment, e, null, null);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]));
    }
    System.out.println("Same sections:");
    pw.iMPP = true;
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        double dif = 0;
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            cr.setInitialAssignment(new Enrollment(cr, i, cfg, sections, assignment));
            w[i] = pw.getWeight(assignment, e, null, null);
            dif = pw.getDifference(e);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]) + " (" + df.format(dif) + ")");
    }
    System.out.println("Same choice sections:");
    pw.iMPP = true;
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        double dif = 0;
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<SctAssignment> other = new HashSet<SctAssignment>();
            other.add(new Section(1, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            cr.setInitialAssignment(new Enrollment(cr, i, cfg, other, assignment));
            w[i] = pw.getWeight(assignment, e, null, null);
            dif = pw.getDifference(e);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]) + " (" + df.format(dif) + ")");
    }
    System.out.println("Same time sections:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double dif = 0;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<SctAssignment> other = new HashSet<SctAssignment>();
            other.add(new Section(1, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null, new Instructor(1, null, "Josef Novak", null)));
            cr.setInitialAssignment(new Enrollment(cr, i, cfg, other, assignment));
            w[i] = pw.getWeight(assignment, e, null, null);
            dif = pw.getDifference(e);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]) + " (" + df.format(dif) + ")");
    }
    System.out.println("Same configuration sections:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        double dif = 0;
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            cr.getSelectedChoices().add(new Choice(cfg));
            cr.setInitialAssignment(null);
            w[i] = pw.getWeight(assignment, e, null, null);
            dif = pw.getDifference(e);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]) + " (" + df.format(dif) + ")");
    }
    System.out.println("Different time sections:");
    Placement q = new Placement(null, new TimeLocation(1, 102, 12, 0, 0, null, null, new BitSet(), 10), new ArrayList<RoomLocation>());
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        double dif = 0;
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<SctAssignment> other = new HashSet<SctAssignment>();
            other.add(new Section(1, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), q, null));
            cr.setInitialAssignment(new Enrollment(cr, i, cfg, other, assignment));
            w[i] = pw.getWeight(assignment, e, null, null);
            dif = pw.getDifference(e);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]) + " (" + df.format(dif) + ")");
    }
    System.out.println("Two sections, one same choice, one same time:");
    for (Request r : s.getRequests()) {
        CourseRequest cr = (CourseRequest) r;
        double[] w = new double[] { 0.0, 0.0, 0.0 };
        double dif = 0;
        for (int i = 0; i < cr.getCourses().size(); i++) {
            Config cfg = new Config(0l, -1, "", cr.getCourses().get(i).getOffering());
            Set<SctAssignment> sections = new HashSet<SctAssignment>();
            sections.add(new Section(0, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            sections.add(new Section(1, 1, "y", new Subpart(1, "Rec", "Rec", cfg, null), p, null));
            Enrollment e = new Enrollment(cr, i, cfg, sections, assignment);
            Set<SctAssignment> other = new HashSet<SctAssignment>();
            other.add(new Section(2, 1, "x", new Subpart(0, "Lec", "Lec", cfg, null), p, null));
            other.add(new Section(3, 1, "y", new Subpart(1, "Rec", "Rec", cfg, null), p, null, new Instructor(1, null, "Josef Novak", null)));
            cr.setInitialAssignment(new Enrollment(cr, i, cfg, other, assignment));
            w[i] = pw.getWeight(assignment, e, null, null);
            dif = pw.getDifference(e);
        }
        System.out.println(cr + ": " + df.format(w[0]) + "  " + df.format(w[1]) + "  " + df.format(w[2]) + " (" + df.format(dif) + ")");
    }
}

Example 5 with SctAssignment

use of org.cpsolver.studentsct.model.SctAssignment in project cpsolver by UniTime.

the class OverlapCheck method check.

/**
     * Check for overlapping sections that are attended by the same student
     * @param a current assignment
     * @return false, if there is such a case
     */
public boolean check(Assignment<Request, Enrollment> a) {
    sLog.info("Checking for overlaps...");
    boolean ret = true;
    for (Student student : getModel().getStudents()) {
        HashMap<TimeLocation, SctAssignment> times = new HashMap<TimeLocation, SctAssignment>();
        for (Request request : student.getRequests()) {
            Enrollment enrollment = a.getValue(request);
            if (enrollment == null)
                continue;
            for (SctAssignment assignment : enrollment.getAssignments()) {
                if (assignment.getTime() == null)
                    continue;
                for (TimeLocation time : times.keySet()) {
                    if (time.hasIntersection(assignment.getTime())) {
                        sLog.error("Student " + student + " assignment " + assignment + " overlaps with " + times.get(time));
                        ret = false;
                    }
                }
                times.put(assignment.getTime(), assignment);
            }
        }
    }
    return ret;
}