Files
chapter-organizer/Core/Calculation/TeamScheduler_DecisionTree.cs
T
2025-08-01 14:10:44 -04:00

101 lines
2.8 KiB
C#

using Core.Entities;
namespace Core.Calculation;
public class TeamScheduler_DecisionTree
{
private readonly IList<Student> _students;
private readonly IList<Team> _teams;
private readonly int _timeSlotCount;
public TeamScheduler_DecisionTree(IList<Team> teams, int timeSlotCount)
{
_timeSlotCount = timeSlotCount;
_teams = teams;
_students = teams.SelectMany(t => t.Students).Distinct().ToList();
}
public IList<Team>[] Solve()
{
var timeSlots = new IList<Team>[_timeSlotCount];
for (var i = 0; i < _timeSlotCount; i++)
timeSlots[i] = new List<Team>();
foreach (var team in _teams.OrderByDescending(t => t.Students.Count))
{
// get overlapping students in each timeslot
var overlaps
= (from tsi in Enumerable.Range(0, timeSlots.Length)
let ts = timeSlots[tsi]
let tss = ts.SelectMany(t => t.Students).Distinct()
select Tuple.Create(tsi, team.Students.Count(tss.Contains)))
.OrderBy(t => t.Item2)
.ThenBy(t => timeSlots[t.Item1].Count);
timeSlots[overlaps.First().Item1].Add(team);
}
return timeSlots;
}
public IList<Team>[] SolveRecursive()
{
// initialize time slots
var timeSlots = new IList<Team>[_timeSlotCount];
for (var i = 0; i < _timeSlotCount; i++)
timeSlots[i] = new List<Team>();
return
(from i in Enumerable.Range(1, 5)
let solution = Recursive(timeSlots, _teams, i)
let overlapCount = Team.GetStudentTeamOverlapCount(solution)
orderby overlapCount
select solution).First();
}
private static IList<Team>[] CopyTimeSlots(IList<Team>[] timeSlots)
{
return timeSlots.Select(ts => (IList<Team>)new List<Team>(ts)).ToArray();
}
private static IList<Team>[] Recursive(IList<Team>[] timeSlots, IList<Team> teams, int overlapTriesStudents = 4)
{
if (!teams.Any())
return timeSlots;
var overlapsTries =
(from team in teams.OrderByDescending(t => t.Students.Count).Take(overlapTriesStudents)
//from ts in timeSlots
from tsi in Enumerable.Range(0, timeSlots.Length)
let ts = timeSlots[tsi]
let tss = ts.SelectMany(t => t.Students)
select Tuple.Create(ts, tsi, team, team.Students.Count(tss.Contains)))
.OrderBy(t => t.Item4)
.ThenBy(t => t.Item1.Count);
var minOverlaps =
(from o in overlapsTries
group o by o.Item4
into oo
orderby oo.Key
select oo).First();
var first = minOverlaps.First();
var results = new List<Tuple<IList<Team>[], int>>();
foreach (var minOverlap in minOverlaps)
{
var timeSlotsAfterAdd = CopyTimeSlots(timeSlots);
timeSlotsAfterAdd[first.Item2].Add(first.Item3);
var remainingTeams = teams.Where(t => t != first.Item3).ToList();
var result = Recursive(timeSlotsAfterAdd, remainingTeams);
results.Add(Tuple.Create(result, Team.GetStudentTeamOverlapCount(result)));
if (minOverlap.Item4 == 0)
break;
}
return results.OrderByDescending(r => r.Item2).First().Item1;
}
}