bitset.hpp

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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Mikael Lagerkvist <lagerkvist@gecode.org>
 *
 *  Contributing authors:
 *     Christian Schulte <schulte@gecode.org>
 *
 *  Copyright:
 *     Mikael Lagerkvist, 2007
 *     Christian Schulte, 2007
 *
 *  Last modified:
 *     $Date: 2009-01-20 23:44:27 +0100 (Tue, 20 Jan 2009) $ by $Author: schulte $
 *     $Revision: 8082 $
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 *  Permission is hereby granted, free of charge, to any person obtaining
 *  a copy of this software and associated documentation files (the
 *  "Software"), to deal in the Software without restriction, including
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 *  permit persons to whom the Software is furnished to do so, subject to
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 */

#include <climits>

namespace Gecode { namespace Int { namespace Extensional {

  class BitSet {
    typedef unsigned int Base;
    Base* data;
    unsigned int size;
  public:
    BitSet(void);
    BitSet(Space& home, int s, bool value = false);
    BitSet(Space& home, const BitSet& bs);
    void init(Space& home, int s, bool value=false);
    bool get(unsigned int i);
    void set(unsigned int i, bool value=true);
  };

  forceinline void
  BitSet::init(Space& home, int s, bool value) {
    size = static_cast<int>(std::ceil(static_cast<double>(s)
                                      /(CHAR_BIT*sizeof(Base))));
    data = home.alloc<Base>(size);
    Base ival = value ? ~0 : 0;
    for (int i = size; i--; ) data[i] = ival;
  }

  forceinline
  BitSet::BitSet(void) : data(NULL), size(0) {}

  forceinline
  BitSet::BitSet(Space& home, int s, bool value)
    : data(NULL), size(0) {
    init(home, s, value);
  }
  forceinline
  BitSet::BitSet(Space& home, const BitSet& bs)
    : data(home.alloc<Base>(bs.size)), size(bs.size) {
    for (int i = size; i--; ) data[i] = bs.data[i];
  }
  forceinline bool
  BitSet::get(unsigned int i) {
    unsigned int pos = i / (sizeof(Base)*CHAR_BIT);
    unsigned int bit = i % (sizeof(Base)*CHAR_BIT);
    assert(pos < size);
    return data[pos] & ((Base)1 << bit);
  }
  forceinline void
  BitSet::set(unsigned int i, bool value) {
    unsigned int pos = i / (sizeof(Base)*CHAR_BIT);
    unsigned int bit = i % (sizeof(Base)*CHAR_BIT);
    assert(pos < size);
    if (value)
      data[pos] |= 1 << bit;
    else
      data[pos] &= ~(1 << bit);
  }

}}}

// STATISTICS: int-other