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package solver.search.restart;
import org.testng.Assert;
import org.testng.annotations.Test;
import solver.Solver;
import solver.constraints.Constraint;
import solver.constraints.IntConstraintFactory;
import solver.search.limits.NodeCounter;
import solver.search.loop.monitors.SearchMonitorFactory;
import solver.variables.IntVar;
import solver.variables.VariableFactory;
/**
* <br/>
*
* @author Charles Prud'homme
* @since 13/05/11
*/
public class RestartTest {
protected static Solver buildQ(int n) {
Solver solver = new Solver();
IntVar[] vars = new IntVar[n];
for (int i = 0; i < vars.length; i++) {
vars[i] = VariableFactory.enumerated("Q_" + i, 1, n, solver);
}
for (int i = 0; i < n - 1; i++) {
for (int j = i + 1; j < n; j++) {
int k = j - i;
Constraint neq = IntConstraintFactory.arithm(vars[i], "!=", vars[j]);
solver.post(neq);
solver.post(IntConstraintFactory.arithm(vars[i], "!=", vars[j], "+", -k));
solver.post(IntConstraintFactory.arithm(vars[i], "!=", vars[j], "+", k));
}
}
return solver;
}
@Test(groups = "1s")
public void testGeometricalRestart1() {
Solver solver = buildQ(4);
SearchMonitorFactory.geometrical(solver, 2, 1.2, new NodeCounter(2), 2);
solver.findAllSolutions();
// not 2, because of restart, that found twice the same solution
Assert.assertEquals(solver.getMeasures().getSolutionCount(), 2);
Assert.assertEquals(solver.getMeasures().getRestartCount(), 2);
Assert.assertEquals(solver.getMeasures().getNodeCount(), 12);
}
@Test(groups = "1s")
public void testLubyRestart1() {
Solver solver = buildQ(4);
SearchMonitorFactory.luby(solver, 2, 2, new NodeCounter(2), 2);
solver.findAllSolutions();
// not 2, because of restart, that found twice the same solution
Assert.assertEquals(solver.getMeasures().getSolutionCount(), 2);
Assert.assertEquals(solver.getMeasures().getRestartCount(), 2);
Assert.assertEquals(solver.getMeasures().getNodeCount(), 11);
}
public final static int[] LUBY_2 = {1, 1, 2, 1, 1, 2, 4, 1, 1, 2, 1, 1, 2, 4, 8, 1, 1, 2, 1, 1, 2, 4, 1, 1, 2, 1, 1, 2, 4, 8, 16};
public final static int[] LUBY_3 = {1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 3, 9,
1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 3, 9,
1, 1, 1, 3, 1, 1, 1, 3, 1, 1, 1, 3, 9, 27};
public final static int[] LUBY_4 = {1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 16,
1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 16,
1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 16,
1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 1, 1, 1, 1, 4, 16, 64
};
public final static int[] GEOMETRIC_1_3 = {1, 2, 2, 3, 3, 4, 5, 7, 9, 11, 14, 18, 24, 31, 40};
private void checkRestart(AbstractRestartStrategy r, double factor, int[] expected) {
r.setGeometricalFactor(factor);
int[] computed = r.getSequenceExample(expected.length);
Assert.assertEquals(computed, expected);
}
@Test(groups = "1s")
public void testRestartStrategy() {
AbstractRestartStrategy r = new LubyRestartStrategy(1, 2);
checkRestart(r, 2, LUBY_2);
checkRestart(r, 3, LUBY_3);
checkRestart(r, 4, LUBY_4);
r = new GeometricalRestartStrategy(1, 1.3);
checkRestart(r, 1.3, GEOMETRIC_1_3);
}
}