private Slot GetNewSlot(CourseClass cc)
{
//TODO: 没有考虑午休
Slot newSlot = null;
int count = 0;
int group = this.configuration.GetStudentsGroupIdx(cc);
bool isFixed = false;
// 尽量选中空slot，最多尝试10次
do
{
// 第几个工作日
int day = this.Rand() % this.configuration.Parameters.WorkingDaysNumber;
// 第几节课开始上，考虑了duration
int time = this.Rand() % (this.configuration.Parameters.NumberOfClassPerDay + 1 - cc.Duration);
// 如果用户有偏好，前5次尝试按照用户偏好优先。如果不能成功，则忽略偏好。
if (count < 5 && cc.ExpectedClassIndexes != null && cc.ExpectedClassIndexes.Length > 0)
{
if (cc.ExpectedClassIndexes.Length == 1)
{
time = cc.ExpectedClassIndexes[0];
}
else
{
int idx = this.Rand() % cc.ExpectedClassIndexes.Length;
time = cc.ExpectedClassIndexes[idx];
}
}
// 得到新的时间槽
newSlot = this.GetSlot(day, group, time);
isFixed = false;
bool isOccupied = false;
for (int i = 0; i < cc.Duration; i++)
{
// 是否包含已经冻结的slot
if (this.Slots[newSlot.SlotIndex + i].IsFixed)
{
isFixed = true;
break;
}
// Slot是否为空，我们希望优先选中空slot
if (this.Slots[newSlot.SlotIndex + i].Classes.Count > 0)
{
isOccupied = true;
}
}
if (!isOccupied)
{
break;
}
}while (isFixed || count++ < 10);
return(newSlot);
}
/// <summary>
/// 随机选择一个可排课的课堂
/// </summary>
/// <returns>一个课堂</returns>
private CourseClass GetRandomUnfixedClass()
{
CourseClass cc = null;
do
{
cc = this.configuration.CourseClasses[this.Rand() % this.configuration.CourseClasses.Count];
}while (cc.IsFixed);
return(cc);
}
// Performs mutation on chromosome
// 在当前染色体上执行变异
public void Mutation()
{
this.SelfCheck();
// 检查是否需要变异
if (this.Rand() % 100 > this.configuration.Parameters.MutationProbability)
{
return;
}
// move selected number of classes at random position
// 随机移动指定数量课堂的时间槽
for (int i = this.configuration.Parameters.MutationSize; i > 0; i--)
{
// 随机选择一个课堂
CourseClass cc = this.GetRandomUnfixedClass();
// 将课堂从现在的时间槽里删除
foreach (var slot in this.GetSlots(cc))
{
slot.Classes.Remove(cc);
}
// 随机决定课堂新的时间槽
int newSlotIndex = this.GetNewSlot(cc).SlotIndex;
// 放入新的时间槽
for (int j = 0; j < cc.Duration; j++)
{
this.Slots[newSlotIndex + j].Classes.Add(cc);
}
// 验证课程节数
var count = this.Slots.FindAll(s => s.Classes.Contains(cc)).Count;
Debug.Assert(cc.Duration == count, "确保排课结果中的课程的节数没有变化");
}
// 重新计算适应度
this.CalculateFitnessAndEvenness();
this.SelfCheck();
}
// Bind group to class
public void AddClass(CourseClass courseClass)
{
CourseClasses.Add(courseClass);
}
// Returns TRUE if another class has same professor.
public bool ProfessorOverlaps(CourseClass c)
{
return(Professor.Equals(c.Professor));
}
// Returns TRUE if another class has one or overlapping student groups.
public bool GroupsOverlap(CourseClass c)
{
return(Groups.Intersect(c.Groups).Any());
}
public int GetStudentsGroupIdx(CourseClass cc)
{
return(this.StudentsGroups.FindIndex(sg => sg.Id == cc.StudentsGroupId));
}
private List <Slot> GetSlots(CourseClass cc)
{
return(this.Slots.FindAll(s => s.Classes.Contains(cc)));
}
