not-first-not-last.hpp

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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Christian Schulte <schulte@gecode.org>
 *
 *  Copyright:
 *     Christian Schulte, 2009
 *
 *  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
 *  the following conditions:
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 *  included in all copies or substantial portions of the Software.
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#include <algorithm>

namespace Gecode { namespace Int { namespace Unary {

  template<class ManTaskView>
  forceinline ExecStatus
  notlast(Space& home, TaskViewArray<ManTaskView>& t) {
    sort<ManTaskView,STO_LCT,true>(t);

    Region r;

    OmegaTree<ManTaskView> o(r,t);
    TaskViewIter<ManTaskView,STO_LST,true> q(r,t);
    int* lct = r.alloc<int>(t.size());

    for (int i=0; i<t.size(); i++)
      lct[i] = t[i].lct();

    for (int i=0; i<t.size(); i++) {
      int j = -1;
      while (q() && (t[i].lct() > t[q.task()].lst())) {
        if ((j >= 0) && (o.ect() > t[q.task()].lst()))
          lct[q.task()] = std::min(lct[q.task()],t[j].lst());
        j = q.task();
        o.insert(j); ++q;
      }
      if ((j >= 0) && (o.ect(i) > t[i].lst()))
        lct[i] = std::min(lct[i],t[j].lst());
    }

    for (int i=0; i<t.size(); i++)
      GECODE_ME_CHECK(t[i].lct(home,lct[i]));

    return ES_OK;
  }

  template<class ManTask>
  ExecStatus
  notfirstnotlast(Space& home, TaskArray<ManTask>& t) {
    TaskViewArray<typename TaskTraits<ManTask>::TaskViewFwd> f(t);
    GECODE_ES_CHECK(notlast(home,f));
    TaskViewArray<typename TaskTraits<ManTask>::TaskViewBwd> b(t);
    return notlast(home,b);
  }

  template<class OptTaskView, class PL>
  forceinline ExecStatus
  notlast(Space& home, Propagator& p, TaskViewArray<OptTaskView>& t) {
    sort<OptTaskView,STO_LCT,true>(t);

    Region r;

    OmegaTree<OptTaskView> o(r,t);
    ManTaskViewIter<OptTaskView,STO_LST,true> q(r,t);
    int* lct = r.alloc<int>(t.size());

    for (int i=0; i<t.size(); i++)
      lct[i] = t[i].lct();

    for (int i=0; i<t.size(); i++) {
      int j = -1;
      while (q() && (t[i].lct() > t[q.task()].lst())) {
        if ((j >= 0) && (o.ect() > t[q.task()].lst()))
          lct[q.task()] = std::min(lct[q.task()],t[j].lst());
        j = q.task();
        o.insert(j); ++q;
      }
      if ((j >= 0) && (o.ect(i) > t[i].lst()))
        lct[i] = std::min(lct[i],t[j].lst());
    }

    {
      int n = t.size();
      for (int i=n; i--; )
        if (t[i].mandatory()) {
          GECODE_ME_CHECK(t[i].lct(home,lct[i]));
        } else if (lct[i] < t[i].ect()) {
          GECODE_ME_CHECK(t[i].excluded(home));
          t[i].cancel(home,p,PL::pc); t[i]=t[--n];
        }
      t.size(n);
    }

    return (t.size() < 2) ? home.ES_SUBSUMED(p) : ES_OK;
  }

  template<class OptTask, class PL>
  ExecStatus
  notfirstnotlast(Space& home, Propagator& p, TaskArray<OptTask>& t) {
    TaskViewArray<typename TaskTraits<OptTask>::TaskViewFwd> f(t);
    GECODE_ES_CHECK((notlast<typename TaskTraits<OptTask>::TaskViewFwd,PL>
                     (home,p,f)));
    TaskViewArray<typename TaskTraits<OptTask>::TaskViewBwd> b(t);
    return notlast<typename TaskTraits<OptTask>::TaskViewBwd,PL>(home,p,b);
  }

}}}

// STATISTICS: int-prop