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virtual-ranges-union.icc

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/*
 *  Main authors:
 *     Christian Schulte <schulte@gecode.org>
 *
 *  Copyright:
 *     Christian Schulte, 2004
 *
 *  Last modified:
 *     $Date: 2006-08-04 16:05:50 +0200 (Fri, 04 Aug 2006) $ by $Author: schulte $
 *     $Revision: 3515 $
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 *  See the file "LICENSE" for information on usage and
 *  redistribution of this file, and for a
 *     DISCLAIMER OF ALL WARRANTIES.
 *
 */

#include "gecode/support/static-pqueue.hh"

namespace Gecode { namespace Iter { namespace Ranges {  namespace Virt {

  class Union : public MinMax, public Iterator {
    Iterator* i;
    Iterator* j;
    Union(const Union&);
  public:


    Union(void);
    Union(Iterator* i, Iterator* j);
    ~Union(void);



    virtual int min(void) const;
    virtual int max(void) const;
    virtual unsigned int width(void) const;



    void operator++(void);
    virtual bool operator()(void);
  };


  class NaryUnion : public MinMax, public Iterator {
  private:
    NaryUnion(const NaryUnion&);
  protected:
    class RangeUnionOrder {
    public:
      bool operator()(const Iterator*, const Iterator*) const;
    };
    RangeUnionOrder order;
    Support::PQueue<Iterator*,RangeUnionOrder> r;
  public:


    NaryUnion(void);
    NaryUnion(Iterator** i, int n);



    virtual int min(void) const;
    virtual int max(void) const;
    virtual unsigned int width(void) const;



    void operator++(void);
    virtual bool operator()(void);
  };



  /*
   * Binary union
   *
   */

  forceinline void
  Union::operator++(void) {
    if (!(*i)() && !(*j)()) {
      finish(); return;
    }
    if (!(*i)()) {
      mi = j->min(); ma = j->max(); ++(*j); return;
    }
    if (!(*j)()) {
      mi = i->min(); ma = i->max(); ++(*i); return;
    }
    if (i->min() < j->min()) {
      mi = i->min(); ma = i->max(); ++(*i);
    } else {
      mi = j->min(); ma = j->max(); ++(*j);
    }
    bool goOn;
    do {
      goOn = false;
      if ((*i)() && (i->min() <= ma+1)) {
        ma = std::max(ma,i->max()); ++(*i); goOn=true;
      }
      if ((*j)() && (j->min() <= ma+1)) {
        ma = std::max(ma,j->max()); ++(*j); goOn=true;
      }
    } while (goOn);
  }


  forceinline
  Union::Union(void) {}

  forceinline
  Union::Union(Iterator* i0, Iterator* j0)
    : i(i0), j(j0) {
    operator++();
  }

  forceinline
  Union::~Union(void) { delete i; delete j; }

  forceinline bool
  Union::operator()(void) { return MinMax::operator()(); }

  forceinline int
  Union::min(void) const { return MinMax::min(); }

  forceinline int
  Union::max(void) const { return MinMax::max(); }

  forceinline unsigned int
  Union::width(void) const { return MinMax::width(); }

  /*
   * Nary Union
   *
   */

  forceinline bool
  NaryUnion::RangeUnionOrder::operator()(const Iterator* a,
                                         const Iterator* b) const {
    return a->min() > b->min();
  }

  inline void
  NaryUnion::operator++(void) {
    if (r.empty()) {
      finish(); return;
    }
    mi = r.top()->min();
    ma = r.top()->max();
    do {
      if (ma < r.top()->max())
        ma = r.top()->max();
      ++(*(r.top()));
      if (!((*r.top()))()) {
        r.remove();
        if (r.empty())
          return;
      } else {
        r.fix();
      }
    } while (ma+1 >= r.top()->min());
  }


  forceinline
  NaryUnion::NaryUnion(void) {}

  inline
  NaryUnion::NaryUnion(Iterator** r0, int n)
    : order(), r(n,order) {
    for (int i = n; i--; )
      if ((*(r0[i]))())
        r.insert(r0[i]);
    operator++();
  }

  forceinline bool
  NaryUnion::operator()(void) { return MinMax::operator()(); }

  forceinline int
  NaryUnion::min(void) const { return MinMax::min(); }

  forceinline int
  NaryUnion::max(void) const { return MinMax::max(); }

  forceinline unsigned int
  NaryUnion::width(void) const { return MinMax::width(); }

}}}}

// STATISTICS: iter-any