/*******************************************************************************
    * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Eclipse Public License v1.0
    * which accompanies this distribution, and is available at
    *  http://www.eclipse.org/legal/epl-v10.html
    *
    * Alternatively, the contents of this file may be used under the terms of
   * either the GNU Lesser General Public License Version 2.1 or later (the
   * "LGPL"), in which case the provisions of the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of the LGPL, and not to allow others to use your version of
   * this file under the terms of the EPL, indicate your decision by deleting
   * the provisions above and replace them with the notice and other provisions
   * required by the LGPL. If you do not delete the provisions above, a recipient
   * may use your version of this file under the terms of the EPL or the LGPL.
   *
   * Based on the original MiniSat specification from:
   *
   * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
   * Sixth International Conference on Theory and Applications of Satisfiability
   * Testing, LNCS 2919, pp 502-518, 2003.
   *
   * See www.minisat.se for the original solver in C++.
   *
   * Contributors:
   *   CRIL - initial API and implementation
   *******************************************************************************/
  package org.sat4j.pb.constraints.pb;
  
  import java.math.BigInteger;
  
  import org.sat4j.core.Vec;
  import org.sat4j.core.VecInt;
  import org.sat4j.specs.IVec;
  import org.sat4j.specs.IVecInt;
  
  /**
   * @author anne
   * 
   */
  public class InternalMapPBStructure {
  
      IVecInt lits;
      IVec<BigInteger> coefs;
      IVecInt allLits;
  
      InternalMapPBStructure(int size) {
          assert size > 0;
          this.allLits = new VecInt(size, -1);
          this.coefs = new Vec<BigInteger>();
          this.lits = new VecInt();
      }
  
      InternalMapPBStructure(PBConstr cpb) {
          this.allLits = new VecInt(cpb.getVocabulary().nVars() * 2 + 2, -1);
          this.coefs = new Vec<BigInteger>(cpb.size());
          this.lits = new VecInt(cpb.size());
          int lit;
          for (int i = 0; i < cpb.size(); i++) {
              assert cpb.get(i) != 0;
              assert cpb.getCoef(i).signum() > 0;
              lit = cpb.get(i);
              this.lits.push(lit);
              assert i + 1 == this.lits.size();
              this.allLits.set(lit, i);
              this.coefs.push(cpb.getCoef(i));
          }
      }
  
      // coefs.get(lit)
      BigInteger get(int lit) {
          assert this.allLits.get(lit) != -1;
          return this.coefs.get(this.allLits.get(lit));
      }
  
      int getLit(int indLit) {
          assert indLit < this.lits.size();
          return this.lits.get(indLit);
      }
  
      BigInteger getCoef(int indLit) {
          assert indLit < this.coefs.size();
          return this.coefs.get(indLit);
      }
  
      // coefs.containsKey(nLitImplied)
      boolean containsKey(int lit) {
          return this.allLits.get(lit) != -1;
      }
  
      int size() {
          return this.lits.size();
      }
  
      // coefs.put(lit, newValue)
      void put(int lit, BigInteger newValue) {
          int indLit = this.allLits.get(lit);
         if (indLit != -1) {
             this.coefs.set(indLit, newValue);
         } else {
             this.lits.push(lit);
             this.coefs.push(newValue);
             this.allLits.set(lit, this.lits.size() - 1);
         }
     }
 
     void changeCoef(int indLit, BigInteger newValue) {
         assert indLit <= this.coefs.size();
         this.coefs.set(indLit, newValue);
     }
 
     // void removeCoef(Integer lit) {
     // coefs.remove(lit);
     void remove(int lit) {
         int indLit = this.allLits.get(lit);
         if (indLit != -1) {
             int tmp = this.lits.last();
             this.coefs.delete(indLit);
             this.lits.delete(indLit);
             this.allLits.set(tmp, indLit);
             this.allLits.set(lit, -1);
         }
     }
 
     void copyCoefs(IVec<BigInteger> dest) {
         this.coefs.copyTo(dest);
     }
 
     void copyCoefs(BigInteger[] dest) {
         this.coefs.copyTo(dest);
     }
 
     void copyLits(IVecInt dest) {
         this.lits.copyTo(dest);
     }
 
     void copyLits(int[] dest) {
         this.lits.copyTo(dest);
     }
 }