Add new model_builder C# samples
This commit is contained in:
Laurent Perron
129
ortools/linear_solver/samples/AssignmentMb.cs
Normal file
129
ortools/linear_solver/samples/AssignmentMb.cs
Normal file
@@ -0,0 +1,129 @@
|
||||
// Copyright 2010-2022 Google LLC
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// [START program]
|
||||
// [START import]
|
||||
using System;
|
||||
using Google.OrTools.ModelBuilder;
|
||||
// [END import]
|
||||
|
||||
public class AssignmentMb
|
||||
{
|
||||
static void Main()
|
||||
{
|
||||
// Data.
|
||||
// [START data_model]
|
||||
int[,] costs = {
|
||||
{ 90, 80, 75, 70 }, { 35, 85, 55, 65 }, { 125, 95, 90, 95 }, { 45, 110, 95, 115 }, { 50, 100, 90, 100 },
|
||||
};
|
||||
int numWorkers = costs.GetLength(0);
|
||||
int numTasks = costs.GetLength(1);
|
||||
// [END data_model]
|
||||
|
||||
// [START model]
|
||||
ModelBuilder model = new ModelBuilder();
|
||||
// [END model]
|
||||
|
||||
// Variables.
|
||||
// [START variables]
|
||||
// x[i, j] is an array of 0-1 variables, which will be 1
|
||||
// if worker i is assigned to task j.
|
||||
Variable[,] x = new Variable[numWorkers, numTasks];
|
||||
for (int i = 0; i < numWorkers; ++i)
|
||||
{
|
||||
for (int j = 0; j < numTasks; ++j)
|
||||
{
|
||||
x[i, j] = model.NewBoolVar($"worker_{i}_task_{j}");
|
||||
}
|
||||
}
|
||||
// [END variables]
|
||||
|
||||
// Constraints
|
||||
// [START constraints]
|
||||
// Each worker is assigned to at most one task.
|
||||
for (int i = 0; i < numWorkers; ++i)
|
||||
{
|
||||
var assignedWork = LinearExpr.NewBuilder();
|
||||
for (int j = 0; j < numTasks; ++j)
|
||||
{
|
||||
assignedWork.Add(x[i, j]);
|
||||
}
|
||||
model.Add(assignedWork <= 1);
|
||||
}
|
||||
|
||||
// Each task is assigned to exactly one worker.
|
||||
for (int j = 0; j < numTasks; ++j)
|
||||
{
|
||||
var assignedWorker = LinearExpr.NewBuilder();
|
||||
for (int i = 0; i < numWorkers; ++i)
|
||||
{
|
||||
assignedWorker.Add(x[i, j]);
|
||||
}
|
||||
model.Add(assignedWorker == 1);
|
||||
}
|
||||
// [END constraints]
|
||||
|
||||
// Objective
|
||||
// [START objective]
|
||||
var objective = LinearExpr.NewBuilder();
|
||||
for (int i = 0; i < numWorkers; ++i)
|
||||
{
|
||||
for (int j = 0; j < numTasks; ++j)
|
||||
{
|
||||
objective.AddTerm(x[i, j], costs[i, j]);
|
||||
}
|
||||
}
|
||||
model.Minimize(objective);
|
||||
// [END objective]
|
||||
|
||||
// [START solver]
|
||||
// Create the model solver with the SCIP backend.
|
||||
ModelSolver solver = new ModelSolver("SCIP");
|
||||
if (!solver.SolverIsSupported())
|
||||
{
|
||||
return;
|
||||
}
|
||||
// [END solver]
|
||||
|
||||
// Solve
|
||||
// [START solve]
|
||||
SolveStatus resultStatus = solver.Solve(model);
|
||||
// [END solve]
|
||||
|
||||
// Print solution.
|
||||
// [START print_solution]
|
||||
// Check that the problem has a feasible solution.
|
||||
if (resultStatus == SolverStatus.OPTIMAL || resultStatus == SolverStatus.FEASIBLE)
|
||||
{
|
||||
Console.WriteLine($"Total cost: {solver.ObjectiveValue}\n");
|
||||
for (int i = 0; i < numWorkers; ++i)
|
||||
{
|
||||
for (int j = 0; j < numTasks; ++j)
|
||||
{
|
||||
// Test if x[i, j] is 0 or 1 (with tolerance for floating point
|
||||
// arithmetic).
|
||||
if (solver.Value(x[i, j]) > 0.9)
|
||||
{
|
||||
Console.WriteLine($"Worker {i} assigned to task {j}. Cost: {costs[i, j]}");
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
Console.WriteLine("No solution found.");
|
||||
}
|
||||
// [END print_solution]
|
||||
}
|
||||
}
|
||||
// [END program]
|
||||
131
ortools/linear_solver/samples/BinPackingMb.cs
Normal file
131
ortools/linear_solver/samples/BinPackingMb.cs
Normal file
@@ -0,0 +1,131 @@
|
||||
// Copyright 2010-2022 Google LLC
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// [START program]
|
||||
// [START import]
|
||||
using System;
|
||||
using Google.OrTools.ModelBuilder;
|
||||
// [END import]
|
||||
|
||||
// [START program_part1]
|
||||
public class BinPackingMb
|
||||
{
|
||||
// [START data_model]
|
||||
class DataModel
|
||||
{
|
||||
public static double[] Weights = { 48, 30, 19, 36, 36, 27, 42, 42, 36, 24, 30 };
|
||||
public int NumItems = Weights.Length;
|
||||
public int NumBins = Weights.Length;
|
||||
public double BinCapacity = 100.0;
|
||||
}
|
||||
// [END data_model]
|
||||
public static void Main()
|
||||
{
|
||||
// [START data]
|
||||
DataModel data = new DataModel();
|
||||
// [END data]
|
||||
// [END program_part1]
|
||||
|
||||
// [START model]
|
||||
ModelBuilder model = new ModelBuilder();
|
||||
// [END model]
|
||||
|
||||
// [START program_part2]
|
||||
// [START variables]
|
||||
Variable[,] x = new Variable[data.NumItems, data.NumBins];
|
||||
for (int i = 0; i < data.NumItems; i++)
|
||||
{
|
||||
for (int j = 0; j < data.NumBins; j++)
|
||||
{
|
||||
x[i, j] = model.NewBoolVar($"x_{i}_{j}");
|
||||
}
|
||||
}
|
||||
Variable[] y = new Variable[data.NumBins];
|
||||
for (int j = 0; j < data.NumBins; j++)
|
||||
{
|
||||
y[j] = model.NewBoolVar($"y_{j}");
|
||||
}
|
||||
// [END variables]
|
||||
|
||||
// [START constraints]
|
||||
for (int i = 0; i < data.NumItems; ++i)
|
||||
{
|
||||
var assignedWork = LinearExpr.NewBuilder();
|
||||
for (int j = 0; j < data.NumBins; ++j)
|
||||
{
|
||||
assignedWork.Add(x[i, j]);
|
||||
}
|
||||
model.Add(assignedWork == 1);
|
||||
}
|
||||
|
||||
for (int j = 0; j < data.NumBins; ++j)
|
||||
{
|
||||
var load = LinearExpr.NewBuilder();
|
||||
for (int i = 0; i < data.NumItems; ++i)
|
||||
{
|
||||
load.AddTerm(x[i, j], DataModel.Weights[i]);
|
||||
}
|
||||
model.Add(y[j] * data.BinCapacity >= load);
|
||||
}
|
||||
// [END constraints]
|
||||
|
||||
// [START objective]
|
||||
model.Minimize(LinearExpr.Sum(y));
|
||||
// [END objective]
|
||||
|
||||
// [START solver]
|
||||
// Create the model solver with the SCIP backend.
|
||||
ModelSolver solver = new ModelSolver("SCIP");
|
||||
if (!solver.SolverIsSupported())
|
||||
{
|
||||
return;
|
||||
}
|
||||
// [END solver]
|
||||
|
||||
// [START solve]
|
||||
SolveStatus resultStatus = solver.Solve(model);
|
||||
// [END solve]
|
||||
|
||||
// [START print_solution]
|
||||
// Check that the problem has an optimal solution.
|
||||
if (resultStatus != SolveStatus.OPTIMAL)
|
||||
{
|
||||
Console.WriteLine("The problem does not have an optimal solution!");
|
||||
return;
|
||||
}
|
||||
Console.WriteLine($"Number of bins used: {solver.ObjectiveValue}");
|
||||
double TotalWeight = 0.0;
|
||||
for (int j = 0; j < data.NumBins; ++j)
|
||||
{
|
||||
double BinWeight = 0.0;
|
||||
if (solver.Value(y[j]) == 1)
|
||||
{
|
||||
Console.WriteLine($"Bin {j}");
|
||||
for (int i = 0; i < data.NumItems; ++i)
|
||||
{
|
||||
if (solver.Value(x[i, j]) == 1)
|
||||
{
|
||||
Console.WriteLine($"Item {i} weight: {DataModel.Weights[i]}");
|
||||
BinWeight += DataModel.Weights[i];
|
||||
}
|
||||
}
|
||||
Console.WriteLine($"Packed bin weight: {BinWeight}");
|
||||
TotalWeight += BinWeight;
|
||||
}
|
||||
}
|
||||
Console.WriteLine($"Total packed weight: {TotalWeight}");
|
||||
// [END print_solution]
|
||||
}
|
||||
}
|
||||
// [END program_part2]
|
||||
// [END program]
|
||||
@@ -51,7 +51,7 @@ public class SimpleMipProgramMb
|
||||
// [END objective]
|
||||
|
||||
// [START solver]
|
||||
// Create the model solver with the GLOP backend.
|
||||
// Create the model solver with the SCIP backend.
|
||||
ModelSolver solver = new ModelSolver("SCIP");
|
||||
if (!solver.SolverIsSupported())
|
||||
{
|
||||
|
||||
Reference in New Issue
Block a user