89 lines
3.6 KiB
Java
89 lines
3.6 KiB
Java
/**
|
|
* Copyright (c) 1999-2011, Ecole des Mines de Nantes All rights reserved. Redistribution and use in
|
|
* source and binary forms, with or without modification, are permitted provided that the following
|
|
* conditions are met:
|
|
*
|
|
* <p>* Redistributions of source code must retain the above copyright notice, this list of
|
|
* conditions and the following disclaimer. * Redistributions in binary form must reproduce the
|
|
* above copyright notice, this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution. * Neither the name of the Ecole des Mines
|
|
* de Nantes nor the names of its contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
*
|
|
* <p>THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
|
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
|
|
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
package com.google.ortools.contrib;
|
|
|
|
import com.google.ortools.constraintsolver.DecisionBuilder;
|
|
import com.google.ortools.constraintsolver.IntVar;
|
|
import com.google.ortools.constraintsolver.OptimizeVar;
|
|
import com.google.ortools.constraintsolver.SearchMonitor;
|
|
import com.google.ortools.constraintsolver.SolutionCollector;
|
|
import com.google.ortools.constraintsolver.Solver;
|
|
|
|
/**
|
|
* Golomb ruler problem <br>
|
|
*
|
|
* @author Charles Prud'homme
|
|
* @since 17/03/11
|
|
*/
|
|
public class GolombRuler {
|
|
static {
|
|
System.loadLibrary("jniortools");
|
|
}
|
|
|
|
/** Golomb Ruler Problem. */
|
|
private static void solve(int m) {
|
|
Solver solver = new Solver("GR " + m);
|
|
|
|
IntVar[] ticks = solver.makeIntVarArray(m, 0, ((m < 31) ? (1 << (m + 1)) - 1 : 9999), "ticks");
|
|
|
|
solver.addConstraint(solver.makeEquality(ticks[0], 0));
|
|
|
|
for (int i = 0; i < ticks.length - 1; i++) {
|
|
solver.addConstraint(solver.makeLess(ticks[i], ticks[i + 1]));
|
|
}
|
|
|
|
IntVar[] diff = new IntVar[(m * m - m) / 2];
|
|
|
|
for (int k = 0, i = 0; i < m - 1; i++) {
|
|
for (int j = i + 1; j < m; j++, k++) {
|
|
diff[k] = solver.makeDifference(ticks[j], ticks[i]).var();
|
|
solver.addConstraint(solver.makeGreaterOrEqual(diff[k], (j - i) * (j - i + 1) / 2));
|
|
}
|
|
}
|
|
|
|
solver.addConstraint(solver.makeAllDifferent(diff));
|
|
|
|
// break symetries
|
|
if (m > 2) {
|
|
solver.addConstraint(solver.makeLess(diff[0], diff[diff.length - 1]));
|
|
}
|
|
|
|
OptimizeVar opt = solver.makeMinimize(ticks[m - 1], 1);
|
|
DecisionBuilder db =
|
|
solver.makePhase(ticks, solver.CHOOSE_MIN_SIZE_LOWEST_MIN, solver.ASSIGN_MIN_VALUE);
|
|
SolutionCollector collector = solver.makeLastSolutionCollector();
|
|
collector.add(ticks);
|
|
collector.addObjective(ticks[m - 1]);
|
|
SearchMonitor log = solver.makeSearchLog(10000, opt);
|
|
solver.solve(db, opt, log, collector);
|
|
System.out.println("Optimal solution = " + collector.objectiveValue(0));
|
|
for (int i = 0; i < m; ++i) {
|
|
System.out.print("[" + collector.value(0, ticks[i]) + "] ");
|
|
}
|
|
System.out.println();
|
|
}
|
|
|
|
public static void main(String[] args) throws Exception {
|
|
GolombRuler.solve(8);
|
|
}
|
|
}
|