基于Timefold提供的GitHub项目（https://github.com/TimefoldAI/timefold-quickstarts/tree/stable/technology/java-spring-boot）我想为可能发生的以下场景实现一个约束在大学：
假设对于特定的一天（星期一），我们有 7 个时间段（上午 8 点 - 上午 10 点、上午 10 点 - 上午 12 点、...、晚上 8 点到晚上 10 点）和 4 个不同的课程要在当天分配。我们希望确保特定日期的日程安排中没有任何间隙（例如超过 2 小时）。
我目前的尝试如下：
Constraint tooMuchGap(ConstraintFactory constraintFactory){
// 4 hours gaps between lessons for students in the same day
//todo solve this problem-> we receive pairs that are not consecutives
return constraintFactory
//select each 2 pair of different lessons
.forEach(Lesson.class)
.join(Lesson.class,
//with the same student group
Joiners.equal(Lesson::getStudentGroup),
//in the same day
Joiners.equal((lesson) -> lesson.getTimeslot().getDayOfWeek()),
Joiners.lessThan((lesson -> lesson.getTimeslot().getId())))
.filter((lesson1, lesson2) -> {
Duration between = Duration.between(lesson1.getTimeslot().getEndTime(),
lesson2.getTimeslot().getStartTime());
return !between.isNegative() && between.compareTo(Duration.ofHours(3)) > 0;
})
.penalize(HardSoftScore.ONE_SOFT)
//.justifyWith()
.asConstraint("Too much gap between the courses");
}
对于这个测试用例：
@Test
void tooMuchGap(){
StudentGroup studentGroup = new StudentGroup(1L,"Group1");
Lesson firstTuesdayLesson = new Lesson(1, "subject1", new Teacher(1L, "Teacher2"), studentGroup, TIMESLOT2, ROOM1);
Lesson secondTuesdayLesson = new Lesson(2, "subject2", new Teacher(2L, "Teacher1"), studentGroup, TIMESLOT3, ROOM1);
Lesson thirdTuesdayLesson = new Lesson(3, "subject3", new Teacher(3L, "Teacher3"), studentGroup, TIMESLOT6, ROOM1);
Lesson fourthTuesdayLesson = new Lesson(4, "subject4", new Teacher(4L, "Teacher3"), studentGroup, TIMESLOT7, ROOM1);
constraintVerifier.verifyThat(TimetableConstraintProvider::tooMuchGap)
.given(firstTuesdayLesson, secondTuesdayLesson, thirdTuesdayLesson, fourthTuesdayLesson)
.penalizesBy(1);
}
我收到以下输出：
2024-03-13 22:45:12.697 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson1's timeslot: Timeslot(id=2, dayOfWeek=TUESDAY, startTime=12:00, endTime=14:00)
2024-03-13 22:45:12.707 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson2's timeslot: Timeslot(id=3, dayOfWeek=TUESDAY, startTime=14:30, endTime=16:30)
2024-03-13 22:45:12.707 INFO [main ] - c.t.t.s.TimetableConstraintProvider - ----------------------------------
2024-03-13 22:45:12.707 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson1's timeslot: Timeslot(id=2, dayOfWeek=TUESDAY, startTime=12:00, endTime=14:00)
2024-03-13 22:45:12.707 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson2's timeslot: Timeslot(id=6, dayOfWeek=TUESDAY, startTime=19:00, endTime=21:00)
2024-03-13 22:45:12.707 INFO [main ] - c.t.t.s.TimetableConstraintProvider - ----------------------------------
2024-03-13 22:45:12.709 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson1's timeslot: Timeslot(id=3, dayOfWeek=TUESDAY, startTime=14:30, endTime=16:30)
2024-03-13 22:45:12.709 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson2's timeslot: Timeslot(id=6, dayOfWeek=TUESDAY, startTime=19:00, endTime=21:00)
2024-03-13 22:45:12.709 INFO [main ] - c.t.t.s.TimetableConstraintProvider - ----------------------------------
2024-03-13 22:45:12.709 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson1's timeslot: Timeslot(id=2, dayOfWeek=TUESDAY, startTime=12:00, endTime=14:00)
2024-03-13 22:45:12.709 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson2's timeslot: Timeslot(id=7, dayOfWeek=TUESDAY, startTime=21:00, endTime=23:00)
2024-03-13 22:45:12.709 INFO [main ] - c.t.t.s.TimetableConstraintProvider - ----------------------------------
2024-03-13 22:45:12.710 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson1's timeslot: Timeslot(id=3, dayOfWeek=TUESDAY, startTime=14:30, endTime=16:30)
2024-03-13 22:45:12.710 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson2's timeslot: Timeslot(id=7, dayOfWeek=TUESDAY, startTime=21:00, endTime=23:00)
2024-03-13 22:45:12.710 INFO [main ] - c.t.t.s.TimetableConstraintProvider - ----------------------------------
2024-03-13 22:45:12.710 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson1's timeslot: Timeslot(id=6, dayOfWeek=TUESDAY, startTime=19:00, endTime=21:00)
2024-03-13 22:45:12.710 INFO [main ] - c.t.t.s.TimetableConstraintProvider - The lesson2's timeslot: Timeslot(id=7, dayOfWeek=TUESDAY, startTime=21:00, endTime=23:00)
2024-03-13 22:45:12.710 INFO [main ] - c.t.t.s.TimetableConstraintProvider - ----------------------------------
java.lang.AssertionError: Broken expectation.
Constraint: com.timetablealgo.testingtimetablealgo.solver/Too much gap between the courses
Expected penalty: 1 (class java.lang.Integer)
Actual penalty: 3 (class java.lang.Integer)
Explanation of score (0hard/-3soft):
Constraint matches:
-3soft: constraint (Too much gap between the courses) has 3 matches:
-1soft: justified with ([Lesson(id=2, subject=subject2, teacher=Teacher(id=2, name=Teacher2, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=2, dayOfWeek=TUESDAY, startTime=12:00, endTime=14:00), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null)), Lesson(id=5, subject=subject3, teacher=Teacher(id=3, name=Teacher3, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=6, dayOfWeek=TUESDAY, startTime=19:00, endTime=21:00), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null))])
-1soft: justified with ([Lesson(id=2, subject=subject2, teacher=Teacher(id=2, name=Teacher2, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=2, dayOfWeek=TUESDAY, startTime=12:00, endTime=14:00), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null)), Lesson(id=6, subject=subject4, teacher=Teacher(id=3, name=Teacher3, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=7, dayOfWeek=TUESDAY, startTime=21:00, endTime=23:00), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null))])
...
Indictments:
-2soft: indicted with (Lesson(id=2, subject=subject2, teacher=Teacher(id=2, name=Teacher2, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=2, dayOfWeek=TUESDAY, startTime=12:00, endTime=14:00), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null))) has 2 matches:
-1soft: constraint (Too much gap between the courses)
-1soft: constraint (Too much gap between the courses)
-2soft: indicted with (Lesson(id=6, subject=subject4, teacher=Teacher(id=3, name=Teacher3, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=7, dayOfWeek=TUESDAY, startTime=21:00, endTime=23:00), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null))) has 2 matches:
-1soft: constraint (Too much gap between the courses)
-1soft: constraint (Too much gap between the courses)
-1soft: indicted with (Lesson(id=5, subject=subject3, teacher=Teacher(id=3, name=Teacher3, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=6, dayOfWeek=TUESDAY, startTime=19:00, endTime=21:00), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null))) has 1 matches:
-1soft: constraint (Too much gap between the courses)
-1soft: indicted with (Lesson(id=3, subject=subject1, teacher=Teacher(id=1, name=Teacher1, preferredTimeslot=null), studentGroup=StudentGroup(id=1, year=null, name=Group1, group=null, semiGroup=null, numberOfStudents=30), type=null, year=null, timeslot=Timeslot(id=3, dayOfWeek=TUESDAY, startTime=14:30, endTime=16:30), room=Room(id=1, name=Room1, capacity=0, type=null, building=null, dotari=null))) has 1 matches:
-1soft: constraint (Too much gap between the courses)
我的问题是如何获得连续对（基于他们的时间段）进行评估？对于这种情况，我只想获取以下对：(Timeslot2 和 Timeslot3)、(Timeslot3 和 Timeslot6)、(Timeslot6 和 Timeslot7)。
由于
consecutiveifNotExistsConstraint tooMuchGap(ConstraintFactory constraintFactory){
// 4 hours gaps between lessons for students in the same day
return constraintFactory
//select each 2 pair of different lessons
.forEach(Lesson.class)
.join(Lesson.class,
//with the same student group
Joiners.equal(Lesson::getStudentGroup),
//in the same day
Joiners.equal((lesson) -> lesson.getTimeslot().getDayOfWeek()),
// First starts before second
Joiners.lessThan((lesson) -> lesson.getTimeslot().getStartTime())
)
.ifNotExists(Lesson.class,
//with the same student group
Joiners.equal((a,b) -> a.getStudentGroup(), Lesson::getStudentGroup),
//in the same day
Joiners.equal((a,b) -> a.getTimeslot().getDayOfWeek(), (lesson) -> lesson.getTimeslot().getDayOfWeek()),
//is between the two timeslots
Joiners.lessThan((a,b) -> a.getTimeslot().getStartTime(), (lesson) -> lesson.getTimeslot().getStartTime()),
Joiners.greaterThan((a,b) -> b.getTimeslot().getStartTime(), (lesson) -> lesson.getTimeslot().getStartTime())
)
.filter((lesson1, lesson2) -> {
Duration between = Duration.between(lesson1.getTimeslot().getEndTime(),
lesson2.getTimeslot().getStartTime());
return !between.isNegative() && between.compareTo(Duration.ofHours(3)) > 0;
})
.penalize(HardSoftScore.ONE_SOFT)
//.justifyWith()
.asConstraint("Too much gap between the courses");
}