org.sat4j.tools.encoding
Class Commander

java.lang.Object
  org.sat4j.tools.encoding.EncodingStrategyAdapter
      org.sat4j.tools.encoding.Commander

public class Commander
extends EncodingStrategyAdapter

The case "at most one" is introduced in W. Klieber and G. Kwon "Efficient CNF encoding for selecting 1 from N objects" in Fourth Workshop on Constraints in Formal Verification, 2007. The generalization to the "at most k" case is described in A. M. Frisch and P . A. Giannaros, "SAT Encodings of the At-Most-k Constraint", in International Workshop on Modelling and Reformulating Constraint Satisfaction Problems, 2010

Since:

2.3.1

Author:

sroussel

Constructor Summary

Commander()

Method Summary

IConstr	addAtMost(ISolver solver, IVecInt literals, int degree)
IConstr	addAtMostOne(ISolver solver, IVecInt literals) In this encoding, variables are partitioned in groups.

Methods inherited from class org.sat4j.tools.encoding.EncodingStrategyAdapter

addAtLeast, addAtLeastOne, addExactly, addExactlyOne, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Commander

public Commander()

Method Detail

addAtMostOne

public IConstr addAtMostOne(ISolver solver,
                            IVecInt literals)
                     throws ContradictionException

In this encoding, variables are partitioned in groups. Kwon and Klieber claim that the fewest clauses are produced when the size of the groups is 3, thus leading to 3.5 clauses and introducing n/2 variables.

Overrides:

addAtMostOne in class EncodingStrategyAdapter

Throws:

ContradictionException

addAtMost

public IConstr addAtMost(ISolver solver,
                         IVecInt literals,
                         int degree)
                  throws ContradictionException

Overrides:

addAtMost in class EncodingStrategyAdapter

Throws:

ContradictionException