93 lines
2.8 KiB
Java
Executable File
93 lines
2.8 KiB
Java
Executable File
|
|
/*
|
|
* Copyright 2017 Darian Sastre darian.sastre@minimaxlabs.com
|
|
* 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.
|
|
*
|
|
* ************************************************************************
|
|
*
|
|
* This model was created by Hakan Kjellerstrand (hakank@gmail.com)
|
|
*/
|
|
|
|
import com.google.ortools.linearsolver.MPConstraint;
|
|
import com.google.ortools.linearsolver.MPObjective;
|
|
import com.google.ortools.linearsolver.MPSolver;
|
|
import com.google.ortools.linearsolver.MPVariable;
|
|
|
|
public class DietMIP {
|
|
static {
|
|
System.loadLibrary("jniortools");
|
|
}
|
|
|
|
private static MPSolver createSolver(String solverType) {
|
|
try {
|
|
return new MPSolver("MIPDiet", MPSolver.OptimizationProblemType.valueOf(solverType));
|
|
} catch (java.lang.IllegalArgumentException e) {
|
|
System.err.println("Bad solver type: " + e);
|
|
return null;
|
|
}
|
|
}
|
|
|
|
private static void solve(String solverType) {
|
|
MPSolver solver = createSolver(solverType);
|
|
double infinity = MPSolver.infinity();
|
|
|
|
int n = 4; // variables number
|
|
int m = 4; // constraints number
|
|
|
|
int[] price = { 50, 20, 30, 80 };
|
|
|
|
int[] limits = { 500, 6, 10, 8 };
|
|
|
|
int[] calories = { 400, 200, 150, 500 };
|
|
int[] chocolate = { 3, 2, 0, 0 };
|
|
int[] sugar = { 2, 2, 4, 4 };
|
|
int[] fat = { 2, 4, 1, 5 };
|
|
|
|
int[][] values = { calories, chocolate, sugar, fat };
|
|
|
|
MPVariable[] x = solver.makeIntVarArray(n, 0, 100, "x");
|
|
MPObjective objective = solver.objective();
|
|
MPConstraint[] targets = new MPConstraint[4];
|
|
|
|
for (int i = 0; i < n; i++) {
|
|
objective.setCoefficient(x[i], price[i]);
|
|
|
|
// constraints
|
|
targets[i] = solver.makeConstraint(limits[i], infinity);
|
|
for (int j = 0; j < m; j++) {
|
|
targets[i].setCoefficient(x[j], values[i][j]);
|
|
}
|
|
}
|
|
|
|
final MPSolver.ResultStatus resultStatus = solver.solve();
|
|
|
|
/** printing */
|
|
if (resultStatus != MPSolver.ResultStatus.OPTIMAL) {
|
|
System.err.println("The problem does not have an optimal solution!");
|
|
return;
|
|
} else {
|
|
System.out.println("Optimal objective value = " + solver.objective().value());
|
|
|
|
System.out.print("Item quantities: ");
|
|
System.out.print((int) x[0].solutionValue() + " ");
|
|
System.out.print((int) x[1].solutionValue() + " ");
|
|
System.out.print((int) x[2].solutionValue() + " ");
|
|
System.out.print((int) x[3].solutionValue() + " ");
|
|
}
|
|
}
|
|
|
|
public static void main(String[] args) throws Exception {
|
|
solve("CBC_MIXED_INTEGER_PROGRAMMING");
|
|
}
|
|
}
|