text: /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
  /*
   *  Main authors:
   *     Christian Schulte <schulte@gecode.org>
   *
   *  Copyright:
   *     Christian Schulte, 2005
   *
   *  Last modified:
   *     $Date: 2010-07-28 17:35:33 +0200 (Wed, 28 Jul 2010) $ by $Author: schulte $
   *     $Revision: 11294 $
   *
   *  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 <cmath>
  
  namespace Gecode { namespace Iter { namespace Ranges {
  
    /**
     * \brief Range iterator for pointwise product with a positive integer
     *
     * Note that this iterator has a different interface as it can be used
     * for both integer precision as well as double precision (depending
     * on the type \a Val (\c int or \c double) and
     * on the type \a UnsVal (\c unsigned \c int or \c double).
     *
     * \ingroup FuncIterRanges
     */
    template<class Val, class UnsVal, class I>
    class ScaleUp {
    protected:
      /// Iterator to be scaled
      I i;
      /// Scale-factor
      int a;
      /// Current value of range
      Val cur;
      /// Last value of scaled range of \a i
      Val end;
    public:
      /// \name Constructors and initialization
      //@{
      /// Default constructor
      ScaleUp(void);
      /// Initialize with ranges from \a i and scale factor \a a
      ScaleUp(I& i, int a);
      /// Initialize with ranges from \a i and scale factor \a a
      void init(I& i, int a);
      //@}
  
      /// \name Iteration control
      //@{
      /// Test whether iterator is still at a range or done
      bool operator ()(void) const;
      /// Move iterator to next range (if possible)
      void operator ++(void);
      //@}
  
      /// \name Range access
      //@{
      /// Return smallest value of range
      Val min(void) const;
      /// Return largest value of range
      Val max(void) const;
      /// Return width of range (distance between minimum and maximum)
      UnsVal width(void) const;
      //@}
    };
  
    /**
     * \brief Range iterator for pointwise division by a positive integer
     *
     * \ingroup FuncIterRanges
     */
    template<class I>
    class ScaleDown : public MinMax {
    protected:
      /// Iterator to be scaled down
      I i;
      /// Divide by this factor
      int a;
    public:
      /// \name Constructors and initialization
      //@{
      /// Default constructor
      ScaleDown(void);
      /// Initialize with ranges from \a i and scale factor \a a
      ScaleDown(I& i, int a);
      /// Initialize with ranges from \a i and scale factor \a a
      void init(I& i, int a);
      //@}
  
      /// \name Iteration control
      //@{
      /// Move iterator to next range (if possible)
      void operator ++(void);
      //@}
    };
  
  
  
    template<class Val, class UnsVal, class I>
    forceinline
    ScaleUp<Val,UnsVal,I>::ScaleUp(void) {}
  
    template<class Val, class UnsVal, class I>
    inline void
    ScaleUp<Val,UnsVal,I>::init(I& i0, int a0) {
      i = i0; a = a0;
      if (i()) {
        cur = a * i.min();
        end = a * i.max();
      } else {
        cur = 1;
        end = 0;
      }
    }
  
    template<class Val, class UnsVal, class I>
    inline
    ScaleUp<Val,UnsVal,I>::ScaleUp(I& i0, int a0) : i(i0), a(a0) {
      if (i()) {
        cur = a * i.min();
        end = a * i.max();
      } else {
        cur = 1;
        end = 0;
      }
    }
  
    template<class Val, class UnsVal, class I>
    forceinline void
    ScaleUp<Val,UnsVal,I>::operator ++(void) {
      if (a == 1) {
        ++i;
      } else {
        cur += a;
        if (cur > end) {
          ++i;
          if (i()) {
            cur = a * i.min();
            end = a * i.max();
          }
        }
      }
    }
    template<class Val, class UnsVal, class I>
    forceinline bool
    ScaleUp<Val,UnsVal,I>::operator ()(void) const {
      return (a == 1) ? i() : (cur <= end);
    }
  
    template<class Val, class UnsVal, class I>
    forceinline Val
    ScaleUp<Val,UnsVal,I>::min(void) const {
      return (a == 1) ? static_cast<Val>(i.min()) : cur;
    }
    template<class Val, class UnsVal, class I>
    forceinline Val
    ScaleUp<Val,UnsVal,I>::max(void) const {
      return (a == 1) ? static_cast<Val>(i.max()) : cur;
    }
    template<class Val, class UnsVal, class I>
    forceinline UnsVal
    ScaleUp<Val,UnsVal,I>::width(void) const {
      return (a == 1) ?
        static_cast<UnsVal>(i.width()) :
        static_cast<UnsVal>(max - min + 1);
    }
  
  
  
    template<class I>
    forceinline void
    ScaleDown<I>::operator ++(void) {
      finish();
      while ((mi > ma) && i()) {
        mi = static_cast<int>(ceil(static_cast<double>(i.min())/a));
        ma = static_cast<int>(floor(static_cast<double>(i.max())/a));
        ++i;
      }
      while (i()) {
        int n_mi = static_cast<int>(ceil(static_cast<double>(i.min())/a));
        if (n_mi-ma > 1)
          break;
        int n_ma = static_cast<int>(floor(static_cast<double>(i.max())/a));
        if (n_mi <= n_ma) {
          ma = n_ma;
        }
        ++i;
      }
    }
  
    template<class I>
    forceinline
    ScaleDown<I>::ScaleDown(void) {}
  
    template<class I>
    inline void
    ScaleDown<I>::init(I& i0, int a0) {
      i = i0; a = a0;
      operator ++();
    }
  
    template<class I>
    inline
    ScaleDown<I>::ScaleDown(I& i0, int a0) : i(i0), a(a0) {
      i = i0; a = a0;
      operator ++();
    }
  
  }}}
  
  // STATISTICS: iter-any
  
  