/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Guido Tack <tack@gecode.org>
 *
 *  Copyright:
 *     Guido Tack, 2004
 *
 *  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
 *  without limitation the rights to use, copy, modify, merge, publish,
 *  distribute, sublicense, and/or sell copies of the Software, and to
 *  permit persons to whom the Software is furnished to do so, subject to
 *  the following conditions:
 *
 *  The above copyright notice and this permission notice shall be
 *  included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include <gecode/driver.hh>
#include <gecode/int.hh>
#include <gecode/minimodel.hh>
#include <gecode/set.hh>

using namespace Gecode;

/**
 * \brief %Options for %Hamming problems
 *
 */

class HammingOptions : public Options {
private:
  /// Number of bits
  Driver::UnsignedIntOption _bits;
  /// Minimum distance
  Driver::UnsignedIntOption _distance;
  /// Number of symbols
  Driver::UnsignedIntOption _size;

public:
  /// Initialize options for example with name \a s
  HammingOptions(const char* s, unsigned int bits0,
                 unsigned int distance0, unsigned int size0)
  : Options(s),
    _bits("bits","word size in bits",bits0),
    _distance("distance","minimum distance",distance0),
    _size("size","number of symbols",size0) {
    add(_bits); add(_distance); add(_size);
  }

  /// Return number of bits
  unsigned int bits(void) const { return _bits.value(); }
  /// Return minimum distance
  unsigned int distance(void) const { return _distance.value(); }
  /// Return number of symbols
  unsigned int size(void) const { return _size.value(); }

};

/**
 * \brief %Example: Generating %Hamming codes
 *
 * Generate a Hamming code that fits in b-bit words to code n symbols where
 * the Hamming distance between every two symbol codes is at least d.
 * The Hamming distance between two words is the number of bit positions
 * where they differ.
 *
 * \ingroup Example
 *
 */
class Hamming : public Script {
private:
  /// The hamming code
  SetVarArray x;
public:
  /// Actual model
  Hamming(const HammingOptions& opt) :
    Script(opt),
    x(*this,opt.size(),IntSet::empty,1,opt.bits()) {

    if (opt.trace() != 0)
      trace(*this, x, opt.trace());

    SetVarArgs cx(x.size());

    for (int i=x.size(); i--;)
      cx[i] = expr(*this, -x[i]);

    for (int i=0; i<x.size(); i++)
      for (int j=i+1; j<x.size(); j++)
        rel(*this,
            cardinality(x[j] & cx[i]) +
            cardinality(x[i] & cx[j]) >= opt.distance());

    branch(*this, x, SET_VAR_NONE(), SET_VAL_MIN_INC());
  }

  /// Print solution
  virtual void
  print(std::ostream& os) const {
    for (int i=0; i<x.size(); i++) {
      os << "\t[" << i << "] = " << x[i] << std::endl;
    }
  }

  /// Constructor for copying \a s
  Hamming(Hamming& s) : Script(s) {
    x.update(*this, s.x);
  }
  /// Copy during cloning
  virtual Space*
  copy(void) {
    return new Hamming(*this);
  }

};

/** \brief Main-function
 *  \relates Hamming
 */
int
main(int argc, char* argv[]) {
  HammingOptions opt("Hamming",20,3,32);
  opt.parse(argc,argv);
  Script::run<Hamming,DFS,HammingOptions>(opt);
  return 0;
}


// STATISTICS: example-any