89 lines
2.8 KiB
Java
89 lines
2.8 KiB
Java
// Copyright 2010-2024 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// [START program]
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package com.google.ortools.sat.samples;
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import com.google.ortools.Loader;
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import com.google.ortools.sat.CpModel;
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import com.google.ortools.sat.CpSolver;
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import com.google.ortools.sat.CpSolverSolutionCallback;
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import com.google.ortools.sat.IntVar;
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import com.google.ortools.sat.LinearExpr;
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/** Solves an optimization problem and displays all intermediate solutions. */
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public class SolveAndPrintIntermediateSolutionsSampleSat {
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// [START print_solution]
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static class VarArraySolutionPrinterWithObjective extends CpSolverSolutionCallback {
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public VarArraySolutionPrinterWithObjective(IntVar[] variables) {
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variableArray = variables;
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}
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@Override
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public void onSolutionCallback() {
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System.out.printf("Solution #%d: time = %.02f s%n", solutionCount, wallTime());
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System.out.printf(" objective value = %f%n", objectiveValue());
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for (IntVar v : variableArray) {
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System.out.printf(" %s = %d%n", v.getName(), value(v));
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}
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solutionCount++;
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}
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public int getSolutionCount() {
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return solutionCount;
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}
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private int solutionCount;
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private final IntVar[] variableArray;
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}
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// [END print_solution]
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public static void main(String[] args) throws Exception {
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Loader.loadNativeLibraries();
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// Create the model.
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// [START model]
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CpModel model = new CpModel();
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// [END model]
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// Create the variables.
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// [START variables]
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int numVals = 3;
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IntVar x = model.newIntVar(0, numVals - 1, "x");
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IntVar y = model.newIntVar(0, numVals - 1, "y");
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IntVar z = model.newIntVar(0, numVals - 1, "z");
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// [END variables]
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// Create the constraint.
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// [START constraints]
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model.addDifferent(x, y);
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// [END constraints]
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// Maximize a linear combination of variables.
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// [START objective]
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model.maximize(LinearExpr.weightedSum(new IntVar[] {x, y, z}, new long[] {1, 2, 3}));
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// [END objective]
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// Create a solver and solve the model.
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// [START solve]
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CpSolver solver = new CpSolver();
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VarArraySolutionPrinterWithObjective cb =
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new VarArraySolutionPrinterWithObjective(new IntVar[] {x, y, z});
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solver.solve(model, cb);
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// [END solve]
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System.out.println(cb.getSolutionCount() + " solutions found.");
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}
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}
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// [END program]
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