/// <summary>
/// Generates a new seed.
/// </summary>
public int GenerateSeed(UserQuestionData userQuestionData, int numSeeds)
{
var existingSeeds = userQuestionData.Submissions
?.Where(uqs => uqs.Seed.HasValue && uqs.Seed < numSeeds)
?.GroupBy(uqs => uqs.Seed.Value)
?.ToDictionary(g => g.Key, g => g.Count())
?? new Dictionary <int, int>();
int newSeed;
if (existingSeeds.Count >= numSeeds)
{
newSeed = existingSeeds
.MinBy(kvp => kvp.Value)
.Key;
}
else
{
do
{
newSeed = _randomNumberProvider.NextInt() % numSeeds;
} while (existingSeeds.ContainsKey(newSeed));
}
return(newSeed);
}
/// <summary>
/// Returns the next question ID to use.
/// </summary>
public int GetNextQuestionId(
UserQuestionData userQuestionData,
IList <int> availableQuestionIds)
{
var seenQuestionIds = userQuestionData
?.Submissions
?.Where(uqs => uqs.Seed.HasValue)
?.GroupBy(uqs => uqs.Seed.Value)
?.ToDictionary(g => g.Key, g => g.Count())
?? new Dictionary <int, int>();
var validQuestionIds = new HashSet <int>(availableQuestionIds);
var unseenQuestionIds = validQuestionIds
.Except(seenQuestionIds.Keys)
.ToList();
if (unseenQuestionIds.Any())
{
var randomIndex = _randomNumberProvider.NextInt() % unseenQuestionIds.Count;
return(unseenQuestionIds[randomIndex]);
}
else
{
return(seenQuestionIds
.Where(kvp => validQuestionIds.Contains(kvp.Key))
.MinBy(kvp => kvp.Value)
.Key);
}
}
public Dictionary <Student, Project> AllocateProjects(State state)
{
if (state.Students.Count > state.Supervisors.Sum(supervisor => supervisor.Capacity))
{
throw new ArgumentException($"Not enough capacity for the student list provided. Capacity = '{state.Supervisors.Sum(supervisor => supervisor.Capacity)}', Student count = '{state.Students.Count}'", nameof(state));
}
// Assign based on preferences. Highest GPA -> lowest. GPA clashes resolved by random number
var studentsByGpa = state.Students
.Where(student => student.ProjectInterests.Count > 0)
.OrderByDescending(student => student.Gpa)
.ThenBy(student => _randomNumberProvider.NextInt(state.Students.Count));
_logger.LogInformation("Assigning students to projects based on their preferences, ordered by GPA.");
foreach (var student in studentsByGpa)
{
_logger.LogTrace("Trying to assign a project to student '{0}'", student.Id);
var project = student.ProjectInterests.FirstOrDefault(projectInterest => projectInterest.HasSpaceRemaining);
if (project == null)
{
_logger.LogInformation("None of student '{0}'s preferences have space remaining. Skipping for now.", student.Id);
continue;
}
_logger.LogTrace("Student '{0}'s preference #{1} is still available. Assigning...", student.Id, student.ProjectInterests.IndexOf(project) + 1);
_studentRepository.AssignProject(student, project);
}
_logger.LogInformation("All student preferences assigned (where available)");
// Randomly assign remaining students
var projectsLeft = state.Projects
.Where(project => project.HasSpaceRemaining)
.ToList();
var studentsLeft = state.Students
.Where(student => !student.HasProject)
.ToList();
_logger.LogInformation("Assigning remaining {0} students a project at random.", studentsLeft.Count);
foreach (var student in studentsLeft)
{
var project = projectsLeft[_randomNumberProvider.NextInt(projectsLeft.Count)];
_studentRepository.AssignProject(student, project);
if (!project.HasSpaceRemaining)
{
projectsLeft.Remove(project);
}
if (!project.Supervisor.HasSpaceRemaining)
{
foreach (var supervisorProject in project.Supervisor.Projects)
{
if (projectsLeft.Contains(supervisorProject))
{
projectsLeft.Remove(supervisorProject);
}
}
}
}
return(state.Students.ToDictionary(
student => student,
student => student.Project
));
}
