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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Christian Schulte <schulte@gecode.org>
*
* Copyright:
* Christian Schulte, 2006
*
* 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.
*
*/
namespace Gecode { namespace Int { namespace Count {
template<class VX, class VY>
forceinline
EqInt<VX,VY>::EqInt(Home home, ViewArray<VX>& x, int n_s, VY y, int c)
: IntBase<VX,VY>(home,x,n_s,y,c) {}
template<class VX, class VY>
ExecStatus
EqInt<VX,VY>::post(Home home, ViewArray<VX>& x, VY y, int c) {
// Eliminate decided views
int n_x = x.size();
for (int i=n_x; i--; )
switch (holds(x[i],y)) {
case RT_FALSE:
x[i] = x[--n_x]; break;
case RT_TRUE:
x[i] = x[--n_x]; c--; break;
case RT_MAYBE:
break;
default:
GECODE_NEVER;
}
x.size(n_x);
// RHS too small or too large
if ((c < 0) || (c > n_x))
return ES_FAILED;
// All views must be different
if (c == 0)
return post_false(home,x,y);
// All views must be equal
if (c == n_x)
return post_true(home,x,y);
// Compute how many subscriptions must be created
int n_s = std::max(c,n_x-c)+1;
assert(n_s <= n_x);
(void) new (home) EqInt<VX,VY>(home,x,n_s,y,c);
return ES_OK;
}
template<class VX, class VY>
forceinline
EqInt<VX,VY>::EqInt(Space& home, EqInt<VX,VY>& p)
: IntBase<VX,VY>(home,p) {}
template<class VX, class VY>
Actor*
EqInt<VX,VY>::copy(Space& home) {
return new (home) EqInt<VX,VY>(home,*this);
}
template<class VX, class VY>
ExecStatus
EqInt<VX,VY>::propagate(Space& home, const ModEventDelta&) {
// Eliminate decided views from subscribed views
int n_x = x.size();
for (int i=n_s; i--; )
switch (holds(x[i],y)) {
case RT_FALSE:
x[i].cancel(home,*this,PC_INT_DOM);
x[i]=x[--n_s]; x[n_s]=x[--n_x];
break;
case RT_TRUE:
x[i].cancel(home,*this,PC_INT_DOM);
x[i]=x[--n_s]; x[n_s]=x[--n_x]; c--;
break;
case RT_MAYBE:
break;
default:
GECODE_NEVER;
}
x.size(n_x);
if ((c < 0) || (c > n_x))
return ES_FAILED;
// Eliminate decided views from unsubscribed views
for (int i=n_x; i-- > n_s; )
switch (holds(x[i],y)) {
case RT_FALSE: x[i]=x[--n_x]; break;
case RT_TRUE: x[i]=x[--n_x]; c--; break;
case RT_MAYBE: break;
default: GECODE_NEVER;
}
x.size(n_x);
if ((c < 0) || (c > n_x))
return ES_FAILED;
if (c == 0) {
// All views must be different
GECODE_ES_CHECK(post_false(home,x,y));
return home.ES_SUBSUMED(*this);
}
if (c == n_x) {
// All views must be equal
GECODE_ES_CHECK(post_true(home,x,y));
return home.ES_SUBSUMED(*this);
}
int m = std::max(c,n_x-c)+1;
assert(m <= n_x);
// Now, there must be new subscriptions from x[n_s] up to x[m-1]
while (n_s < m)
x[n_s++].subscribe(home,*this,PC_INT_DOM,false);
return ES_FIX;
}
}}}
// STATISTICS: int-prop