Skip to content

Commit

Permalink
Student Scheduling Solver: Limit Constraints
Browse files Browse the repository at this point in the history 
- when chosing among adepts (for a conflict) in class, course, configuration, or reservation limit constraints, prefer course requests in the following order
  - dummy students before other (only when PreferDummyStudents is true)
  - non-priority students over priority students
  - less critical courses over more critical courses
  - assignments without a reservation over assignments with a reservation
  - among the rest, prefer requests with higher value (lower priority, alternative over first choice, etc.)
  • Loading branch information
@tomas-muller
tomas-muller committed Jun 25, 2020
1 parent 01f8e05 commit a50b1d9
Show file tree
Hide file tree
Showing 4 changed files with 101 additions and 230 deletions.
138 changes: 92 additions & 46 deletions src/org/cpsolver/studentsct/constraint/ConfigLimit.java
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
package org.cpsolver.studentsct.constraint;

import java.util.ArrayList;
import java.util.List;
import java.util.Collection;
import java.util.Set;

import org.cpsolver.ifs.assignment.Assignment;
Expand All @@ -11,6 +11,7 @@
import org.cpsolver.studentsct.model.Config;
import org.cpsolver.studentsct.model.Enrollment;
import org.cpsolver.studentsct.model.Request;
import org.cpsolver.studentsct.model.Request.RequestPriority;


/**
Expand Down Expand Up @@ -142,7 +143,7 @@ public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollm
// above limit -> compute adepts (current assignments that are not
// yet conflicting)
// exclude all conflicts as well
List<Enrollment> adepts = new ArrayList<Enrollment>(config.getEnrollments(assignment).size());
ArrayList<Enrollment> adepts = new ArrayList<Enrollment>(config.getEnrollments(assignment).size());
for (Enrollment e : config.getEnrollments(assignment)) {
if (e.getRequest().equals(enrollment.getRequest()))
continue;
Expand All @@ -164,49 +165,7 @@ public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollm

// pick adept (prefer dummy students & students w/o reservation), decrease enrollment
// weight, make conflict
List<Enrollment> best = new ArrayList<Enrollment>();
boolean bestDummy = false;
double bestValue = 0;
boolean bestRes = true;
for (Enrollment adept: adepts) {
boolean dummy = adept.getStudent().isDummy();
double value = adept.toDouble(assignment, false);
boolean res = (adept.getReservation() != null);

if (iPreferDummyStudents && dummy != bestDummy) {
if (dummy) {
best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
bestRes = res;
}
continue;
}

if (bestRes != res) {
if (!res) {
best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
bestRes = res;
}
continue;
}

if (best.isEmpty() || value > bestValue) {
if (best.isEmpty()) best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
bestRes = res;
} else if (bestValue == value) {
best.add(adept);
}
}

Enrollment conflict = ToolBox.random(best);
Enrollment conflict = new Adepts(iPreferDummyStudents, adepts, assignment).get();
adepts.remove(conflict);
enrlWeight -= conflict.getRequest().getWeight();
conflicts.add(conflict);
Expand Down Expand Up @@ -254,5 +213,92 @@ public boolean inConflict(Assignment<Request, Enrollment> assignment, Enrollment
public String toString() {
return "ConfigLimit";
}


/**
* Support class to pick an adept (prefer dummy students & students w/o reservation)
*/
static class Adepts {
private ArrayList<Enrollment> iEnrollments;
private double iValue;
private boolean iDummy;
private boolean iPriority;
private RequestPriority iRequestPriority;
private boolean iReservation;
private boolean iConsiderDummy;

public Adepts(boolean preferDummy) {
iConsiderDummy = preferDummy;
iEnrollments = new ArrayList<Enrollment>();
}

public Adepts(boolean preferDummy, int size) {
iConsiderDummy = preferDummy;
iEnrollments = new ArrayList<Enrollment>(size);
}

public Adepts(boolean preferDummy, Collection<Enrollment> adepts, Assignment<Request, Enrollment> assignment) {
iConsiderDummy = preferDummy;
iEnrollments = new ArrayList<Enrollment>(adepts.size());
for (Enrollment adept: adepts)
add(adept, assignment);
}

public void add(Enrollment enrollment, Assignment<Request, Enrollment> assignment) {
double value = enrollment.toDouble(assignment, false);
boolean dummy = enrollment.getStudent().isDummy();
boolean priority = enrollment.getStudent().isPriority();
boolean reservation = (enrollment.getReservation() != null);
RequestPriority rp = enrollment.getRequest().getRequestPriority();
if (iEnrollments.isEmpty()) { // no adepts yet
iValue = value; iDummy = dummy; iPriority = priority; iRequestPriority = rp; iReservation = reservation;
iEnrollments.add(enrollment);
return;
}
if (iConsiderDummy && iDummy != dummy) { // different dummy
if (!dummy) return; // ignore not-dummy students
iEnrollments.clear();
iValue = value; iDummy = dummy; iPriority = priority; iRequestPriority = rp; iReservation = reservation;
iEnrollments.add(enrollment);
return;
}
if (iPriority != priority) { // different priority
if (priority) return; // ignore priority students
iEnrollments.clear();
iValue = value; iDummy = dummy; iPriority = priority; iRequestPriority = rp; iReservation = reservation;
iEnrollments.add(enrollment);
return;
}
if (iRequestPriority != rp) { // different request priority
if (rp.ordinal() < iRequestPriority.ordinal()) return; // ignore more critical courses
iEnrollments.clear();
iValue = value; iDummy = dummy; iPriority = priority; iRequestPriority = rp; iReservation = reservation;
iEnrollments.add(enrollment);
return;
}
if (iReservation != reservation) { // different reservation
if (reservation) return; // ignore students with reservation
iEnrollments.clear();
iValue = value; iDummy = dummy; iPriority = priority; iRequestPriority = rp; iReservation = reservation;
iEnrollments.add(enrollment);
return;
}
// prefer requests with higher value (lower priority)
if (value > iValue) {
iEnrollments.clear();
iValue = value; iDummy = dummy; iPriority = priority; iRequestPriority = rp; iReservation = reservation;
iEnrollments.add(enrollment);
} else if (value == iValue) {
iEnrollments.add(enrollment);
}
}

public Enrollment get() {
if (iEnrollments.isEmpty()) return null;
return ToolBox.random(iEnrollments);
}

public boolean isEmpty() {
return iEnrollments.isEmpty();
}
}
}
31 changes: 2 additions & 29 deletions src/org/cpsolver/studentsct/constraint/CourseLimit.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
import org.cpsolver.ifs.assignment.Assignment;
import org.cpsolver.ifs.model.GlobalConstraint;
import org.cpsolver.ifs.util.DataProperties;
import org.cpsolver.ifs.util.ToolBox;
import org.cpsolver.studentsct.constraint.ConfigLimit.Adepts;
import org.cpsolver.studentsct.model.Course;
import org.cpsolver.studentsct.model.Enrollment;
import org.cpsolver.studentsct.model.Request;
Expand Down Expand Up @@ -163,34 +163,7 @@ public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollm

// pick adept (prefer dummy students), decrease unreserved space,
// make conflict
List<Enrollment> best = new ArrayList<Enrollment>();
boolean bestDummy = false;
double bestValue = 0;
for (Enrollment adept: adepts) {
boolean dummy = adept.getStudent().isDummy();
double value = adept.toDouble(assignment, false);

if (iPreferDummyStudents && dummy != bestDummy) {
if (dummy) {
best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
}
continue;
}

if (best.isEmpty() || value > bestValue) {
if (best.isEmpty()) best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
} else if (bestValue == value) {
best.add(adept);
}
}

Enrollment conflict = ToolBox.random(best);
Enrollment conflict = new Adepts(iPreferDummyStudents, adepts, assignment).get();
adepts.remove(conflict);
enrlWeight -= conflict.getRequest().getWeight();
conflicts.add(conflict);
Expand Down
88 changes: 4 additions & 84 deletions src/org/cpsolver/studentsct/constraint/ReservationLimit.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
import org.cpsolver.ifs.model.GlobalConstraint;
import org.cpsolver.ifs.util.DataProperties;
import org.cpsolver.ifs.util.ToolBox;
import org.cpsolver.studentsct.constraint.ConfigLimit.Adepts;
import org.cpsolver.studentsct.model.Config;
import org.cpsolver.studentsct.model.Enrollment;
import org.cpsolver.studentsct.model.Request;
Expand Down Expand Up @@ -165,34 +166,7 @@ public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollm

// pick adept (prefer dummy students), decrease unreserved space,
// make conflict
List<Enrollment> best = new ArrayList<Enrollment>();
boolean bestDummy = false;
double bestValue = 0;
for (Enrollment adept: adepts) {
boolean dummy = adept.getStudent().isDummy();
double value = adept.toDouble(assignment, false);

if (iPreferDummyStudents && dummy != bestDummy) {
if (dummy) {
best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
}
continue;
}

if (best.isEmpty() || value > bestValue) {
if (best.isEmpty()) best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
} else if (bestValue == value) {
best.add(adept);
}
}

Enrollment conflict = ToolBox.random(best);
Enrollment conflict = new Adepts(iPreferDummyStudents, adepts, assignment).get();
adepts.remove(conflict);
reserved += conflict.getRequest().getWeight();
conflicts.add(conflict);
Expand Down Expand Up @@ -239,34 +213,7 @@ public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollm

// pick adept (prefer dummy students), decrease unreserved space,
// make conflict
List<Enrollment> best = new ArrayList<Enrollment>();
boolean bestDummy = false;
double bestValue = 0;
for (Enrollment adept: adepts) {
boolean dummy = adept.getStudent().isDummy();
double value = adept.toDouble(assignment, false);

if (iPreferDummyStudents && dummy != bestDummy) {
if (dummy) {
best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
}
continue;
}

if (best.isEmpty() || value > bestValue) {
if (best.isEmpty()) best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
} else if (bestValue == value) {
best.add(adept);
}
}

Enrollment conflict = ToolBox.random(best);
Enrollment conflict = new Adepts(iPreferDummyStudents, adepts, assignment).get();
adepts.remove(conflict);
unreserved += conflict.getRequest().getWeight();
conflicts.add(conflict);
Expand Down Expand Up @@ -310,34 +257,7 @@ public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollm

// pick adept (prefer dummy students), decrease unreserved space,
// make conflict
List<Enrollment> best = new ArrayList<Enrollment>();
boolean bestDummy = false;
double bestValue = 0;
for (Enrollment adept: adepts) {
boolean dummy = adept.getStudent().isDummy();
double value = adept.toDouble(assignment, false);

if (iPreferDummyStudents && dummy != bestDummy) {
if (dummy) {
best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
}
continue;
}

if (best.isEmpty() || value > bestValue) {
if (best.isEmpty()) best.clear();
best.add(adept);
bestDummy = dummy;
bestValue = value;
} else if (bestValue == value) {
best.add(adept);
}
}

Enrollment conflict = ToolBox.random(best);
Enrollment conflict = new Adepts(iPreferDummyStudents, adepts, assignment).get();
adepts.remove(conflict);
unreserved += conflict.getRequest().getWeight();
conflicts.add(conflict);
Expand Down
Loading

0 comments on commit a50b1d9

Please sign in to comment.