/**
*
*
* Organizing a day.
*
* Simple scheduling problem.
*
* Problem formulation from ECLiPSe:
* Slides on (Finite Domain) Constraint Logic Programming, page 38f
* http://eclipse-clp.org/reports/eclipse.ppt
*
*
* Also see http://www.hakank.org/google_or_tools/organize_day.py
*
*/
private static void Solve()
{
Solver solver = new Solver("OrganizeDayIntervals");
int n = 4;
int work = 0;
int mail = 1;
int shop = 2;
int bank = 3;
// the valid times of the day
int begin = 9;
int end = 17;
// tasks
int[] tasks = {work, mail, shop, bank};
// durations
int[] durations = {4,1,2,1};
// Arrays for interval variables.
int[] starts_max = { begin,begin,begin,begin };
int[] ends_max = { end -4, end - 1, end - 2, end - 1 };
// task [i,0] must be finished before task [i,1]
int[,] before_tasks = {
{bank, shop},
{mail, work}
};
//
// Decision variables
//
IntervalVar[] intervals =
solver.MakeFixedDurationIntervalVarArray(n,
starts_max,
ends_max,
durations,
false,
"task");
//
// Constraints
//
DisjunctiveConstraint disjunctive = intervals.Disjunctive("Sequence");
solver.Add(disjunctive);
// specific constraints
for(int t = 0; t < before_tasks.GetLength(0); t++) {
int before = before_tasks[t, 0];
int after = before_tasks[t, 1];
solver.Add(intervals[after].StartsAfterEnd(intervals[before]));
}
solver.Add(intervals[work].StartsAfter(11));
//
// Search
//
SequenceVar var = disjunctive.SequenceVar();
SequenceVar[] seq_array = new SequenceVar[] { var };
DecisionBuilder db = solver.MakePhase(seq_array, Solver.SEQUENCE_DEFAULT);
solver.NewSearch(db);
while (solver.NextSolution()) {
foreach(int t in tasks) {
Console.WriteLine(intervals[t].ToString());
}
Console.WriteLine();
}
Console.WriteLine("\nSolutions: {0}", solver.Solutions());
Console.WriteLine("WallTime: {0}ms", solver.WallTime());
Console.WriteLine("Failures: {0}", solver.Failures());
Console.WriteLine("Branches: {0} ", solver.Branches());
solver.EndSearch();
}
static void SequenceTest()
{
Solver solver = new Solver("TestSequence");
IntervalVar[] intervals =
solver.MakeFixedDurationIntervalVarArray(10, 0, 10, 5, false, "task");
DisjunctiveConstraint disjunctive = intervals.Disjunctive("Sequence");
SequenceVar var = disjunctive.SequenceVar();
Assignment ass = solver.MakeAssignment();
ass.Add(var);
ass.SetForwardSequence(var, new int[] { 1, 3, 5 });
int[] seq = ass.ForwardSequence(var);
Console.WriteLine(seq.Length);
}
private static void Solve(int first_slot)
{
Console.WriteLine("----------------------------------------------------");
Solver solver = new Solver("SpeakerScheduling");
// the slots each speaker is available
int[][] speaker_availability = {
new int[] {1,3,4,6,7,10,12,13,14,15,16,18,19,20,21,22,23,24,25,33,34,35,36,37,38,39,40,41,43,44,45,46,47,48,49,50,51,52,54,55,56,57,58,59},
new int[] {1,2,7,8,10,11,16,17,18,21,22,23,24,25,33,34,35,36,37,38,39,40,42,43,44,45,46,47,48,49,52,53,54,55,56,57,58,59,60},
new int[] {5,6,7,10,12,14,16,17,21,22,23,24,33,35,37,38,39,40,41,42,43,44,45,46,51,53,55,56,57,58,59},
new int[] {1,2,3,4,5,6,7,11,13,14,15,16,20,24,25,33,34,35,37,38,39,40,41,43,44,45,46,47,48,49,50,51,52,53,54,55,56,58,59,60},
new int[] {4,7,8,9,16,17,19,20,21,22,23,24,25,33,34,35,36,37,38,39,40,41,42,43,49,50,51,53,55,56,57,58,59,60},
new int[] {4,7,9,11,12,13,14,15,16,17,18,22,23,24,33,34,35,36,38,39,42,44,46,48,49,51,53,54,55,56,57},
new int[] {1,2,3,4,5,6,7,33,34,35,36,37,38,39,40,41,42,54,55,56,57,58,59,60},
new int[] {1,3,11,14,15,16,17,21,22,23,24,25,33,35,36,37,39,40,41,42,43,44,45,47,48,49,51,52,53,54,55,56,57,58,59,60},
new int[] {1,2,3,4,5,7,8,9,10,11,13,18,19,20,21,22,23,24,25,33,34,35,36,37,38,39,40,41,42,43,44,45,46,50,51,52,53,54,55,56,57,59,60},
new int[] {24,33,34,35,36,37,38,39,40,41,42,43,45,49,50,51,52,53,54,55,56,57,58,59,60},
new int[] {1,2,3,4,5,6,7,8,9,10,11,12,13,14,16,17,18,19,20,22,23,24,25,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,50,51,52,53,55,56,57,58,59,60},
new int[] {3,4,5,6,13,15,16,17,18,19,21,22,24,25,33,34,35,36,37,39,40,41,42,43,44,45,47,52,53,55,57,58,59,60},
new int[] {4,5,6,8,11,12,13,14,17,19,20,22,23,24,25,33,34,35,36,37,39,40,41,42,43,47,48,49,50,51,52,55,56,57},
new int[] {2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60},
new int[] {12,25,33,35,36,37,39,41,42,43,48,51,52,53,54,57,59,60},
new int[] {4,8,16,17,19,23,25,33,34,35,37,41,44,45,47,48,49,50},
new int[] {3,23,24,25,33,35,36,37,38,39,40,42,43,44,49,50,53,54,55,56,57,58,60},
new int[] {7,13,19,20,22,23,24,25,33,34,35,38,40,41,42,44,45,46,47,48,49,52,53,54,58,59,60}
};
// how long each talk lasts for each speaker
int[] durations = { 1, 2, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
int sum_of_durations = durations.Sum();
int number_of_speakers = durations.Length;
// calculate the total number of slots (maximum in the availability array)
// (and add the max durations)
int last_slot = (from s in Enumerable.Range(0, number_of_speakers)
select speaker_availability[s].Max()).Max();
Console.WriteLine(
"Scheduling {0} speakers, for a total of {1} slots, during [{2}..{3}]",
number_of_speakers, sum_of_durations, first_slot, last_slot);
// Start variable for all talks.
IntVar[] starts = new IntVar[number_of_speakers];
// We store the possible starts for all talks filtered from the
// duration and the speaker availability.
int[][] possible_starts = new int[number_of_speakers][];
for (int speaker = 0; speaker < number_of_speakers; ++speaker)
{
int duration = durations[speaker];
// Let's filter the possible starts.
List<int> filtered_starts = new List<int>();
int availability = speaker_availability[speaker].Length;
for (int index = 0; index < availability; ++index)
{
bool ok = true;
int slot = speaker_availability[speaker][index];
if (slot < first_slot)
{
continue;
}
for (int offset = 1; offset < duration; ++offset)
{
if (index + offset >= availability ||
speaker_availability[speaker][index + offset] != slot + offset)
{
// discontinuity.
ok = false;
break;
}
}
if (ok)
{
filtered_starts.Add(slot);
}
possible_starts[speaker] = filtered_starts.ToArray();
}
starts[speaker] =
solver.MakeIntVar(possible_starts[speaker], "start[" + speaker + "]");
}
List<IntVar>[] contributions_per_slot =
new List<IntVar>[last_slot + 1];
for (int slot = first_slot; slot <= last_slot; ++slot)
{
contributions_per_slot[slot] = new List<IntVar>();
}
for (int speaker = 0; speaker < number_of_speakers; ++speaker)
{
int duration = durations[speaker];
IntVar start_var = starts[speaker];
foreach (int start in possible_starts[speaker])
{
for (int offset = 0; offset < duration; ++offset)
{
contributions_per_slot[start + offset].Add(start_var.IsEqual(start));
}
}
}
// Force the schedule to be consistent.
for (int slot = first_slot; slot <= last_slot; ++slot)
{
solver.Add(
solver.MakeSumLessOrEqual(contributions_per_slot[slot].ToArray(), 1));
}
// Add minimum start info.
for (int speaker = 0; speaker < number_of_speakers; ++speaker)
{
solver.Add(starts[speaker] >= first_slot);
}
// Creates makespan.
IntVar[] end_times = new IntVar[number_of_speakers];
for (int speaker = 0; speaker < number_of_speakers; speaker++)
{
end_times[speaker] = (starts[speaker] + (durations[speaker] - 1)).Var();
}
IntVar last_slot_var = end_times.Max().VarWithName("last_slot");
// Add trivial bound to objective.
last_slot_var.SetMin(first_slot + sum_of_durations - 1);
// Redundant scheduling constraint.
IntervalVar[] intervals =
solver.MakeFixedDurationIntervalVarArray(starts, durations, "intervals");
DisjunctiveConstraint disjunctive =
solver.MakeDisjunctiveConstraint(intervals, "disjunctive");
solver.Add(disjunctive);
//
// Search
//
List<IntVar> short_talks = new List<IntVar>();
List<IntVar> long_talks = new List<IntVar>();
for (int speaker = 0; speaker < number_of_speakers; ++speaker)
{
if (durations[speaker] == 1)
{
short_talks.Add(starts[speaker]);
}
else
{
long_talks.Add(starts[speaker]);
}
}
OptimizeVar objective_monitor = solver.MakeMinimize(last_slot_var, 1);
DecisionBuilder long_phase =
solver.MakePhase(long_talks.ToArray(),
Solver.CHOOSE_MIN_SIZE_LOWEST_MIN,
Solver.ASSIGN_MIN_VALUE);
DecisionBuilder short_phase =
new FlowAssign(short_talks.ToArray(), first_slot, last_slot_var);
DecisionBuilder obj_phase =
solver.MakePhase(last_slot_var,
Solver.CHOOSE_FIRST_UNBOUND,
Solver.ASSIGN_MIN_VALUE);
DecisionBuilder main_phase =
solver.Compose(long_phase, short_phase, obj_phase);
solver.NewSearch(main_phase, objective_monitor);
while (solver.NextSolution())
{
Console.WriteLine("\nLast used slot: " + (last_slot_var.Value()));
Console.WriteLine("Speakers (start..end):");
for (int s = 0; s < number_of_speakers; s++)
{
long sstart = starts[s].Value();
Console.WriteLine(" - speaker {0,2}: {1,2}..{2,2}", (s + 1),
sstart, (sstart + durations[s] - 1));
}
}
Console.WriteLine("\nSolutions: {0}", solver.Solutions());
Console.WriteLine("WallTime: {0}ms", solver.WallTime());
Console.WriteLine("Failures: {0}", solver.Failures());
Console.WriteLine("Branches: {0} ", solver.Branches());
solver.EndSearch();
}