Adds a slack based LCDS

org.sat4j.pb/src/main/java/org/sat4j/pb/lcds/PBGlucoseLCDS.java

@@ -79,6 +79,12 @@ public class PBGlucoseLCDS<D extends DataStructureFactory>
                 new RatioCoefficientsDegreeLBDComputerStrategy());
     }
 
+    public static <D extends DataStructureFactory> LearnedConstraintsDeletionStrategy newSlack(
+            Solver<D> solver, ConflictTimer timer) {
+        return new PBGlucoseLCDS<D>(solver, timer,
+                new SlackLBDComputerStrategy());
+    }
+
     @Override
     public void init() {
         super.init();

org.sat4j.pb/src/main/java/org/sat4j/pb/lcds/SlackLBDComputerStrategy.java

+package org.sat4j.pb.lcds;
+
+import java.math.BigInteger;
+
+import org.sat4j.minisat.core.ILits;
+import org.sat4j.pb.constraints.pb.PBConstr;
+
+public class SlackLBDComputerStrategy implements ILBDComputerStrategy {
+
+    @Override
+    public void init(int howmany) {
+        // TODO Auto-generated method stub
+
+    }
+
+    @Override
+    public int computeLBD(ILits voc, PBConstr constr, int propagated) {
+        BigInteger slack = constr.getSumCoefs().subtract(constr.getDegree());
+        if (slack.bitLength() < Integer.SIZE) {
+            return slack.intValue();
+        }
+        return Integer.MAX_VALUE;
+    }
+
+}

org.sat4j.sat/src/main/java/org/sat4j/sat/KTHLauncher.java

@@ -502,6 +502,11 @@ public class KTHLauncher {
                             .newRatio(cpsolver, timer);
                     cpsolver.setLearnedConstraintsDeletionStrategy(lcds);
 
+                } else if ("slack".equals(value)) {
+                    LearnedConstraintsDeletionStrategy lcds = PBGlucoseLCDS
+                            .newSlack(cpsolver, timer);
+                    cpsolver.setLearnedConstraintsDeletionStrategy(lcds);
+
                 } else {
                     log(value
                             + " is not a supported value for option deletion-strategy");