static void Main()
{
CpModel model = new CpModel();
// Three weeks.
int horizon = 100;
int num_tasks = 4;
IntVar[] starts = new IntVar[num_tasks];
IntVar[] ends = new IntVar[num_tasks];
IntervalVar[] intervals = new IntervalVar[num_tasks];
ILiteral[] presences = new ILiteral[num_tasks];
IntVar[] ranks = new IntVar[num_tasks];
IntVar true_var = model.NewConstant(1);
// Creates intervals, half of them are optional.
for (int t = 0; t < num_tasks; ++t)
{
starts[t] = model.NewIntVar(0, horizon, String.Format("start_{0}", t));
int duration = t + 1;
ends[t] = model.NewIntVar(0, horizon, String.Format("end_{0}", t));
if (t < num_tasks / 2)
{
intervals[t] = model.NewIntervalVar(starts[t], duration, ends[t],
String.Format("interval_{0}", t));
presences[t] = true_var;
}
else
{
presences[t] = model.NewBoolVar(String.Format("presence_{0}", t));
intervals[t] = model.NewOptionalIntervalVar(
starts[t], duration, ends[t], presences[t],
String.Format("o_interval_{0}", t));
}
// Ranks = -1 if and only if the tasks is not performed.
ranks[t] =
model.NewIntVar(-1, num_tasks - 1, String.Format("rank_{0}", t));
}
// Adds NoOverlap constraint.
model.AddNoOverlap(intervals);
// Adds ranking constraint.
RankTasks(model, starts, presences, ranks);
// Adds a constraint on ranks.
model.Add(ranks[0] < ranks[1]);
// Creates makespan variable.
IntVar makespan = model.NewIntVar(0, horizon, "makespan");
for (int t = 0; t < num_tasks; ++t)
{
model.Add(ends[t] <= makespan).OnlyEnforceIf(presences[t]);
}
// Minimizes makespan - fixed gain per tasks performed.
// As the fixed cost is less that the duration of the last interval,
// the solver will not perform the last interval.
IntVar[] presences_as_int_vars = new IntVar[num_tasks];
for (int t = 0; t < num_tasks; ++t)
{
presences_as_int_vars[t] = (IntVar)presences[t];
}
model.Minimize(2 * makespan - 7 * presences_as_int_vars.Sum());
// Creates a solver and solves the model.
CpSolver solver = new CpSolver();
CpSolverStatus status = solver.Solve(model);
if (status == CpSolverStatus.Optimal)
{
Console.WriteLine(String.Format("Optimal cost: {0}",
solver.ObjectiveValue));
Console.WriteLine(String.Format("Makespan: {0}", solver.Value(makespan)));
for (int t = 0; t < num_tasks; ++t)
{
if (solver.BooleanValue(presences[t]))
{
Console.WriteLine(String.Format(
"Task {0} starts at {1} with rank {2}",
t, solver.Value(starts[t]), solver.Value(ranks[t])));
}
else
{
Console.WriteLine(String.Format(
"Task {0} in not performed and ranked at {1}", t,
solver.Value(ranks[t])));
}
}
}
else
{
Console.WriteLine(
String.Format("Solver exited with nonoptimal status: {0}", status));
}
}
public static void Main(String[] args)
{
// Instantiate the data problem.
// [START data]
int[] Weights = { 48, 30, 42, 36, 36, 48, 42, 42, 36, 24, 30, 30, 42, 36, 36 };
int[] Values = { 10, 30, 25, 50, 35, 30, 15, 40, 30, 35, 45, 10, 20, 30, 25 };
int NumItems = Weights.Length;
int[] allItems = Enumerable.Range(0, NumItems).ToArray();
int[] BinCapacities = { 100, 100, 100, 100, 100 };
int NumBins = BinCapacities.Length;
int[] allBins = Enumerable.Range(0, NumBins).ToArray();
// [END data]
// Model.
// [START model]
CpModel model = new CpModel();
// [END model]
// Variables.
// [START variables]
ILiteral[,] x = new ILiteral[NumItems, NumBins];
foreach (int i in allItems)
{
foreach (int b in allBins)
{
x[i, b] = model.NewBoolVar($"x_{i}_{b}");
}
}
// [END variables]
// Constraints.
// [START constraints]
// Each item is assigned to at most one bin.
foreach (int i in allItems)
{
List <ILiteral> literals = new List <ILiteral>();
foreach (int b in allBins)
{
literals.Add(x[i, b]);
}
model.AddAtMostOne(literals);
}
// The amount packed in each bin cannot exceed its capacity.
foreach (int b in allBins)
{
List <ILiteral> items = new List <ILiteral>();
foreach (int i in allItems)
{
items.Add(x[i, b]);
}
model.Add(LinearExpr.WeightedSum(items, Weights) <= BinCapacities[b]);
}
// [END constraints]
// Objective.
// [START objective]
LinearExprBuilder obj = LinearExpr.NewBuilder();
foreach (int i in allItems)
{
foreach (int b in allBins)
{
obj.AddTerm(x[i, b], Values[i]);
}
}
model.Maximize(obj);
// [END objective]
// Solve
// [START solve]
CpSolver solver = new CpSolver();
CpSolverStatus status = solver.Solve(model);
// [END solve]
// Print solution.
// [START print_solution]
// Check that the problem has a feasible solution.
if (status == CpSolverStatus.Optimal || status == CpSolverStatus.Feasible)
{
Console.WriteLine($"Total packed value: {solver.ObjectiveValue}");
double TotalWeight = 0.0;
foreach (int b in allBins)
{
double BinWeight = 0.0;
double BinValue = 0.0;
Console.WriteLine($"Bin {b}");
foreach (int i in allItems)
{
if (solver.BooleanValue(x[i, b]))
{
Console.WriteLine($"Item {i} weight: {Weights[i]} values: {Values[i]}");
BinWeight += Weights[i];
BinValue += Values[i];
}
}
Console.WriteLine("Packed bin weight: " + BinWeight);
Console.WriteLine("Packed bin value: " + BinValue);
TotalWeight += BinWeight;
}
Console.WriteLine("Total packed weight: " + TotalWeight);
}
else
{
Console.WriteLine("No solution found.");
}
// [END print_solution]
// [START statistics]
Console.WriteLine("Statistics");
Console.WriteLine($" conflicts: {solver.NumConflicts()}");
Console.WriteLine($" branches : {solver.NumBranches()}");
Console.WriteLine($" wall time: {solver.WallTime()}s");
// [END statistics]
}
static void Solve(int first_slot)
{
Console.WriteLine("----------------------------------------------------");
// 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 {number_of_speakers} speakers, for a total of " +
$"{sum_of_durations} slots, during [{first_slot}..{last_slot}]");
CpModel model = new CpModel();
// We store the possible entries (var, start) for all talks filtered
// from the duration and the speaker availability.
List <Entry>[] entries = new List <Entry> [number_of_speakers];
for (int speaker = 0; speaker < number_of_speakers; ++speaker)
{
entries[speaker] = new List <Entry>();
}
List <IntVar>[] contributions_per_slot = new List <IntVar> [last_slot + 1];
for (int slot = 1; slot <= last_slot; ++slot)
{
contributions_per_slot[slot] = new List <IntVar>();
}
for (int speaker = 0; speaker < number_of_speakers; ++speaker)
{
List <IntVar> all_vars = new List <IntVar>();
int duration = durations[speaker];
// Let's filter the possible starts.
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)
{
IntVar var = model.NewBoolVar("speaker " + (speaker + 1) + " starts at " + slot);
entries[speaker].Add(new Entry(var, slot));
all_vars.Add(var);
for (int offset = 0; offset < duration; ++offset)
{
contributions_per_slot[slot + offset].Add(var);
}
}
}
model.Add(all_vars.ToArray().Sum() == 1);
}
// Force the schedule to be consistent.
for (int slot = first_slot; slot <= last_slot; ++slot)
{
model.Add(contributions_per_slot[slot].ToArray().Sum() <= 1);
}
// Creates last_slot.
IntVar last_slot_var = model.NewIntVar(
first_slot + sum_of_durations - 1, last_slot, "last_slot");
for (int speaker = 0; speaker < number_of_speakers; speaker++)
{
int duration = durations[speaker];
foreach (Entry e in entries[speaker])
{
model.Add(last_slot_var >= e.start + duration - 1).OnlyEnforceIf(e.var);
}
}
model.Minimize(last_slot_var);
// Creates the solver and solve.
CpSolver solver = new CpSolver();
solver.StringParameters = "num_search_workers:8";
CpSolverStatus status = solver.Solve(model);
if (status == CpSolverStatus.Optimal)
{
Console.WriteLine("\nLast used slot: " + solver.Value(last_slot_var));
Console.WriteLine("Speakers (start..end):");
for (int speaker = 0; speaker < number_of_speakers; speaker++)
{
foreach (Entry e in entries[speaker])
{
if (solver.BooleanValue(e.var))
{
Console.WriteLine(
" - speaker {0,2}: {1,2}..{2,2}", (speaker + 1),
e.start, (e.start + durations[speaker] - 1));
}
}
}
}
// Statistics.
Console.WriteLine(solver.ResponseStats());
}