/*
 *  Main authors:
 *     Guido Tack <tack@gecode.org>
 *     Gabor Szokoli <szokoli@gecode.org>
 *     Christian Schulte <schulte@gecode.org>
 *
 *  Copyright:
 *     Guido Tack, 2004
 *     Christian Schulte, 2004
 *     Gabor Szokoli, 2004
 *
 *  Last modified:
 *     $Date: 2006-07-19 14:57:38 +0200 (Wed, 19 Jul 2006) $ by $Author: schulte $
 *     $Revision: 3413 $
 *
 *  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.
 *
 */

namespace Gecode { namespace Set {

  /*
   * Range lists
   *
   */

#define GECODE_SET_RL2PD(r) reinterpret_cast<ptrdiff_t>(r)
#define GECODE_SET_PD2RL(p) reinterpret_cast<RangeList*>(p)

  forceinline
  RangeList::RangeList(void) {}

  forceinline
  RangeList::RangeList(int min, int max, RangeList* p, RangeList* n)
    : _min(min), _max(max) {
    _next = GECODE_SET_PD2RL(GECODE_SET_RL2PD(p)^GECODE_SET_RL2PD(n));     
  }

  forceinline RangeList*
  RangeList::next(const RangeList* p) const {
    return GECODE_SET_PD2RL(GECODE_SET_RL2PD(_next)^GECODE_SET_RL2PD(p));
  }
  forceinline RangeList*
  RangeList::prev(const RangeList* n) const {
    return GECODE_SET_PD2RL(GECODE_SET_RL2PD(_next)^GECODE_SET_RL2PD(n));
  }
  forceinline void
  RangeList::prevnext(RangeList* p, RangeList* n) {
    _next = GECODE_SET_PD2RL(GECODE_SET_RL2PD(p)^GECODE_SET_RL2PD(n));
  }
  forceinline void
  RangeList::next(RangeList* o, RangeList* n) {
    _next = GECODE_SET_PD2RL(GECODE_SET_RL2PD(_next)^
			     (GECODE_SET_RL2PD(o)^GECODE_SET_RL2PD(n)));
  }
  forceinline void
  RangeList::prev(RangeList* o, RangeList* n) {
    _next = GECODE_SET_PD2RL(GECODE_SET_RL2PD(_next)^
			     (GECODE_SET_RL2PD(o)^GECODE_SET_RL2PD(n)));
  }
  forceinline void
  RangeList::fix(RangeList* n) {
    _next = n;
  }

  forceinline void
  RangeList::min(int n) {
    _min = n;
  }
  forceinline void
  RangeList::max(int n) {
    _max = n;
  }

  forceinline int
  RangeList::min(void) const {
    return _min;
  }
  forceinline int
  RangeList::max(void) const {
    return _max;
  }
  forceinline unsigned int
  RangeList::width(void) const {
    return _max - _min + 1;
  }


  forceinline void
  RangeList::operator delete(void*) {}

  forceinline void
  RangeList::operator delete(void*, Space* home) {
    GECODE_NEVER;
  }

  forceinline void*
  RangeList::operator new(size_t s, Space* home) {
    assert(s == sizeof(RangeList));
    return home->fl_alloc<sizeof(RangeList)>();
  }

  forceinline void
  RangeList::dispose(Space* home, RangeList* p, RangeList* l) {
    RangeList* c = this;
    while (c != l) {
      RangeList* n = c->next(p);
      c->fix(n);
      p=c; c=n;
    }
    home->fl_dispose<sizeof(RangeList)>(this,l);
  }

#undef GECODE_SET_RL2PD
#undef GECODE_SET_PD2RL


  /*
   * BndSet
   *
   */

  forceinline
  BndSet::BndSet(void) :
    first(NULL), last(NULL), _size(0) {}

  forceinline RangeList*
  BndSet::fst(void) const {
    return first;
  }

  forceinline RangeList*
  BndSet::lst(void) const {
    return last;
  }

  forceinline void
  BndSet::dispose(Space* home) {
    if (fst()!=NULL)
      fst()->dispose(home,NULL,lst());
  }

  forceinline void
  BndSet::fst(RangeList* f) {
    first = f;
  }

  forceinline void
  BndSet::lst(RangeList* l) {
    last = l;
  }

  forceinline
  BndSet::BndSet(Space* home, int mn, int mx) {
    RangeList* p = 
      new (home) RangeList(mn,mx,NULL,NULL);
    fst(p); lst(p);
    _size = mx-mn+1;
  }

  forceinline RangeList*
  BndSet::ranges(void) const {
    return fst();
  }

  forceinline unsigned int
  BndSet::size(void) const {
    return _size;
  }

  forceinline bool
  BndSet::empty(void) const {
    return (_size==0);
  }

  forceinline int
  BndSet::min(void) const {
    if (fst()==NULL) { return MIN_OF_EMPTY; }
    else { return fst()->min(); }
  }

  forceinline int
  BndSet::max(void) const {
    if (lst()==NULL) { return MAX_OF_EMPTY; }
    else { return lst()->max(); }
  }

  // nth smallest element
  forceinline int
  BndSet::minN(unsigned int n) const {
    RangeList* p=NULL;
    RangeList* c=fst();
    while (c!=NULL){
      if (c->width() > n){
	return(c->min()+n);
      } else {
	n-=c->width();
	RangeList* nc=c->next(p);
	p=c; c=nc;
      }
    }
    return MIN_OF_EMPTY;
  }

  // nth largest element
  forceinline int
  BndSet::maxN(unsigned int n) const {
    RangeList* p=NULL;
    RangeList* c=lst();
    while (c!=NULL){
      if (c->width() > n){
	return(c->max()-n);
      } else {
	n-=c->width();
	RangeList* nc=c->next(p);
	p=c; c=nc;
      }
    }
    return MAX_OF_EMPTY;
  }

  forceinline void
  BndSet::update(Space* home, BndSet& d) {
    if ( d.fst() == fst()) { return; }
    if (fst()!=NULL) { fst()->dispose(home,NULL,lst()); }
    _size = d.size();
    if (_size==0) { fst(NULL); lst(NULL); return ; }

    int n=0;
    {
      RangeList* p = NULL;
      RangeList* c = d.fst();
      while (c!=NULL) {
	RangeList* nc=c->next(p);
	p=c; c=nc; n++;
      }
    }

    RangeList* r = reinterpret_cast<RangeList*>
      (home->alloc(sizeof(RangeList)*n));
    fst(r); lst(r+n-1);

    {
      RangeList* p = NULL;
      RangeList* c = d.lst();
      for (int i=n; i--; ) {
	r[i].min(c->min());
	r[i].max(c->max());
	r[i].prevnext(&r[i-1],&r[i+1]);

	RangeList* nc=c->next(p);
	p=c; c=nc;
      }
      r[0].prev(&r[-1],NULL); 
      r[n-1].next(&r[n],NULL);
    }

  }

  template <class I> forceinline bool
  BndSet::overwrite(Space* home, I& ri) {
    // Is new domain empty?
    if (!ri()) {
      //Was it empty?
      if (fst()==NULL)
	return false;
      fst()->dispose(home,NULL,lst());
      _size=0; fst(NULL); lst(NULL);
      return true;
    }

    RangeList* f =
      new (home) RangeList(ri.min(),ri.max(),NULL,NULL);
    RangeList* l = f;
    unsigned int s = ri.width();

    ++ri;
    
    while (ri()){
      RangeList *n = new (home) RangeList(ri.min(),ri.max(),l,NULL);
      l->next(NULL,n);
      l=n;
      s += ri.width();
      ++ri;
    }

    if (fst() != NULL)
      fst()->dispose(home,NULL,lst());
    fst(f); lst(l);

    // If the size did not change, nothing changed, as overwriting
    // must not at the same time include and exclude elements.
    if (size() == s)
      return false;

    _size = s;
    return true;
  }

  forceinline void
  BndSet::linkTo(Space* home, const BndSet& that){
    if (fst()!=NULL){
      assert(lst()!=NULL);
      assert(fst()!= that.fst());
      fst()->dispose(home,NULL,lst());
    }
    fst(that.fst());
    lst(that.lst());
    _size = that.size();
    assert(isConsistent());
  }

  forceinline bool
  BndSet::in(int i) const {
    RangeList *p = NULL;
    RangeList *c = fst();
    while (c) {
      if (c->min() <= i && c->max() >= i)
	return true;
      if (c->min() > i)
	return false;
      RangeList* nc = c->next(p);
      p=c; c=nc;
    }
    return false;
  }

  /*
   * Forward range iterator for BndSets
   *
   */

  forceinline
  BndSetRanges::BndSetRanges(void) {}

  forceinline
  BndSetRanges::BndSetRanges(const BndSet& s) :
    p(NULL), c(s.ranges()) {}

  forceinline void
  BndSetRanges::init(const BndSet& s) {
    p = NULL;
    c = s.ranges();
  }

  forceinline bool
  BndSetRanges::operator()(void) const {
    return c != NULL;
  }
  forceinline void
  BndSetRanges::operator++(void) {
    const RangeList* n=c->next(p); p=c; c=n;
  }

  forceinline int
  BndSetRanges::min(void) const {
    return c->min();
  }
  forceinline int
  BndSetRanges::max(void) const {
    return c->max();
  }
  forceinline unsigned int
  BndSetRanges::width(void) const {
    return c->width();
  }

  /*
   * GLBndSet
   *
   */

  forceinline
  GLBndSet::GLBndSet(Space* home) {}

  forceinline
  GLBndSet::GLBndSet(Space* home, int mi, int ma)
    : BndSet(home,mi,ma) { assert(mi<=ma); }

  forceinline
  GLBndSet::GLBndSet(Space* home, const IntSet& s)
    : BndSet(home,s) {}

  forceinline void
  GLBndSet::init(Space* home) { fst(NULL); lst(NULL); _size = 0; }

  forceinline bool
  GLBndSet::include(Space* home, int mi, int ma) {
    assert(ma >= mi);
    if (fst()==NULL) {
      RangeList* p = new (home) RangeList(mi,ma,NULL,NULL);
      fst(p);
      lst(p);
      _size=ma-mi+1;
      return true;
    }
    bool ret = include_full(home, mi, ma);
    assert(isConsistent());
    return ret;
  }

  template <class I> bool
  GLBndSet::includeI(Space* home, I& i) {
    if (!i())
      return false;
    BndSetRanges j(*this);
    Iter::Ranges::Union<BndSetRanges,I> ij(j,i);
    bool me = overwrite(home, ij);
    assert(isConsistent());
    return me;
  }


  /*
   * LUBndSet
   *
   */

  forceinline
  LUBndSet::LUBndSet(void) {}

  forceinline
  LUBndSet::LUBndSet(Space* home)
    : BndSet(home,Limits::Set::int_min,Limits::Set::int_max) {}

  forceinline
  LUBndSet::LUBndSet(Space* home, int mi, int ma)
    : BndSet(home,mi,ma) { assert(mi<=ma); }

  forceinline
  LUBndSet::LUBndSet(Space* home, const IntSet& s)
    : BndSet(home,s) {}

  forceinline void
  LUBndSet::init(Space* home) {
    RangeList *p =
      new (home) RangeList(Limits::Set::int_min,
			   Limits::Set::int_max,
			   NULL,NULL);
    fst(p);
    lst(p);
    _size = Limits::Set::card_max;
  }

  forceinline bool
  LUBndSet::exclude(Space* home, int mi, int ma) {
    assert(ma >= mi);
    if ((mi > max()) || (ma < min())) { return false; }
    if (mi <= min() && ma >= max() ) { //the range covers the whole set
      fst()->dispose(home,NULL,lst()); fst(NULL); lst(NULL);
      _size=0;
      return true;
    }
    bool ret =  exclude_full(home, mi, ma);
    assert(isConsistent());
    return ret;
  }

  template <class I> bool
  LUBndSet::intersectI(Space* home, I& i) {
    if (fst()==NULL) { return false; }
    if (!i()) {
      fst()->dispose(home,NULL,lst()); fst(NULL); lst(NULL);
      _size=0;
      return true;
    }
    BndSetRanges j(*this);
    Iter::Ranges::Inter<BndSetRanges,I> ij(j,i);
    bool ret = overwrite(home, ij);
    assert(isConsistent());
    return ret;
  }

  template <class I> bool
  LUBndSet::excludeI(Space* home, I& i) {
    if (!i()) { return false; }
    BndSetRanges j(*this);
    Iter::Ranges::Diff<BndSetRanges,I> ij(j,i);
    bool ret = overwrite(home, ij);
    assert(isConsistent());
    return ret;
  }

  /*
   * A complement iterator spezialized for the BndSet limits
   *
   */
  template <class I>
  RangesCompl<I>::RangesCompl(void) {}

  template <class I>
  RangesCompl<I>::RangesCompl(I& i)
    : Iter::Ranges::Compl<Limits::Set::int_min,
			  Limits::Set::int_max,
			  I>(i) {}

  template <class I> void
  RangesCompl<I>::init(I& i) {
    Iter::Ranges::Compl<Limits::Set::int_min,
      Limits::Set::int_max,I>::init(i);
  }

}}

// STATISTICS: set-var