purge.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
 *
 *  Last modified:
 *     $Date: 2011-07-12 18:03:22 +0200 (Tue, 12 Jul 2011) $ by $Author: tack $
 *     $Revision: 12176 $
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
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namespace Gecode { namespace Int {

  template<class OptTask, PropCond pc>
  ExecStatus
  purge(Space& home, Propagator& p, TaskArray<OptTask>& t) {
    int n=t.size();
    for (int i=n; i--; )
      if (t[i].excluded()) {
        t[i].cancel(home,p,pc); t[i]=t[--n];
      }
    t.size(n);

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

  template<class OptTask, PropCond pc, class Cap>
  ExecStatus
  purge(Space& home, Propagator& p, TaskArray<OptTask>& t, Cap c) {
    int n=t.size();
    for (int i=n; i--; )
      if (t[i].excluded()) {
        t[i].cancel(home,p,pc); t[i]=t[--n];
      }
    t.size(n);
    if (t.size() == 1) {
      if (t[0].mandatory())
        GECODE_ME_CHECK(c.gq(home, t[0].c()));
      else if (c.min() < t[0].c())
        return ES_OK;
    }

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

// STATISTICS: int-prop