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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Christopher Mears <chris.mears@monash.edu>
*
* Copyright:
* Christopher Mears, 2012
*
* 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 Set { namespace LDSB {
template<class View, int n, class Val, unsigned int a,
class Filter, class Print>
LDSBSetBrancher<View,n,Val,a,Filter,Print>
::LDSBSetBrancher(Home home, ViewArray<View>& x,
ViewSel<View>* vs[n],
ValSelCommitBase<View,Val>* vsc,
SymmetryImp<View>** syms, int nsyms,
BranchFilter<typename LDSBSetBrancher<View,n,Val,a,Filter,Print>::Var> bf,
VarValPrint<typename LDSBSetBrancher<View,n,Val,a,Filter,Print>::Var,Val> vvp)
: LDSBBrancher<View,n,Val,a,Filter,Print>
(home, x, vs, vsc, syms, nsyms, bf, vvp),
_prevPos(-1),
_copiedSyms(nullptr),
_nCopiedSyms(0),
_stable(false) {
// Put all the value symmetries at the end of the list.
int seen = 0;
int dest = this->_nsyms - 1;
for (int i = 0 ; i < this->_nsyms - seen ; i++) {
if (dynamic_cast<ValueSymmetryImp<View>*>(this->_syms[i])) {
SymmetryImp<View>* t = this->_syms[i];
this->_syms[i] = this->_syms[dest];
this->_syms[dest] = t;
dest--;
seen++;
}
}
_nValueSymmetries = seen;
_nNonValueSymmetries = this->_nsyms - seen;
}
template<class View, int n, class Val, unsigned int a,
class Filter, class Print>
LDSBSetBrancher<View,n,Val,a,Filter,Print>::
LDSBSetBrancher(Space& home,
LDSBSetBrancher<View,n,Val,a,Filter,Print>& b)
: LDSBBrancher<View,n,Val,a,Filter,Print>(home,b),
_prevPos(b._prevPos),
_nNonValueSymmetries(b._nNonValueSymmetries),
_nValueSymmetries(b._nValueSymmetries),
_nCopiedSyms(b._nCopiedSyms),
_leftBranchValues(b._leftBranchValues),
_stable(b._stable) {
if (_nCopiedSyms > 0) {
_copiedSyms = home.alloc<ValueSymmetryImp<View>*>(_nCopiedSyms);
for (int i = 0 ; i < _nCopiedSyms ; i++)
_copiedSyms[i] = static_cast<ValueSymmetryImp<View>*>(
b._copiedSyms[i]->copy(home));
} else {
_copiedSyms = nullptr;
}
}
/**
* \brief Bulk update of a value symmetry \a s, using \a usedValues
*
* Calculates the intersection and difference of the values in the
* symmetry and \a usedValues, updates the symmetry to eliminate the
* used values, and makes a new symmetry containing the intersection
* values, if there are at least two. Returns the new symmetry, or
* nullptr if the intersection has fewer than two elements.
*/
template <class View>
ValueSymmetryImp<View>*
specialUpdate(Space& home, ValueSymmetryImp<View>* s, IntSet usedValues) {
// Calculate intersection and difference.
IntArgs intersection;
IntArgs difference;
int n = 0;
for (int i = s->values.next(s->values.offset()) ;
i <= s->values.max_bit() ; i = s->values.next(i+1)) {
n++;
if (usedValues.in(i))
intersection << i;
else
difference << i;
}
for (IntSetValues v(usedValues) ; v() ; ++v) {
s->update(Literal(0, v.val()));
}
if (intersection.size() < 2)
return nullptr;
int *a = new int[intersection.size()];
for (int i = 0 ; i < intersection.size() ; i++) {
a[i] = intersection[i];
}
ValueSymmetryImp<View>* ns =
new (home) ValueSymmetryImp<View>(home, a, intersection.size());
delete [] a;
return ns;
}
template<class View, int n, class Val, unsigned int a,
class Filter, class Print>
void
LDSBSetBrancher<View,n,Val,a,Filter,Print>::
updatePart1(Space& home, int choicePos) {
if (_nValueSymmetries > 0) {
// If this is a different variable from the last commit, restore
// the old value symmetries and update the copy.
if (choicePos != _prevPos) {
if (_prevPos != -1) {
int i = 0;
for (int j = _nNonValueSymmetries ; j < this->_nsyms ; j++) {
this->_syms[j] = _copiedSyms[i];
i++;
}
for (int i = 0 ; i < _nCopiedSyms ; i++) {
ValueSymmetryImp<View>* ns =
specialUpdate(home, _copiedSyms[i], _leftBranchValues);
if (ns) {
this->_syms = home.realloc<SymmetryImp<View>*>(this->_syms,
this->_nsyms,
this->_nsyms+1);
this->_syms[this->_nsyms] = ns;
this->_nsyms++;
this->_nValueSymmetries++;
}
}
}
// Reset for current variable, make copy of value symmetries
_leftBranchValues = IntSet::empty;
_prevPos = choicePos;
if (_nCopiedSyms > 0) home.free(_copiedSyms, _nCopiedSyms);
_nCopiedSyms = _nValueSymmetries;
_copiedSyms = home.alloc<ValueSymmetryImp<View>*>(_nCopiedSyms);
{
int i = 0;
for (int j = _nNonValueSymmetries ; j < this->_nsyms ; j++) {
ValueSymmetryImp<View>* vsi =
static_cast<ValueSymmetryImp<View>*>(this->_syms[j]);
_copiedSyms[i] =
static_cast<ValueSymmetryImp<View>*>(vsi->copy(home));
i++;
}
}
}
}
}
// Compute choice
template<class View, int n, class Val, unsigned int a,
class Filter, class Print>
const Choice*
LDSBSetBrancher<View,n,Val,a,Filter,Print>::choice(Space& home) {
// Making the PVC here is not so nice, I think.
const Choice* c = ViewValBrancher<View,n,Val,a,Filter,Print>::choice(home);
const PosValChoice<Val>* pvc = static_cast<const PosValChoice<Val>* >(c);
// Compute symmetries.
int choicePos = pvc->pos().pos;
delete c;
assert(!_stable);
updatePart1(home, choicePos);
return LDSBBrancher<View,n,Val,a,Filter,Print>::choice(home);
}
template<class View, int n, class Val, unsigned int a,
class Filter, class Print>
ExecStatus
LDSBSetBrancher<View,n,Val,a,Filter,Print>
::commit(Space& home, const Choice& c, unsigned int b) {
const LDSBChoice<Val>& pvc
= static_cast<const LDSBChoice<Val>&>(c);
int choicePos = pvc.pos().pos;
int choiceVal = pvc.val();
if (!_stable)
updatePart1(home, choicePos);
if (b == 0) {
IntArgs ia;
for (IntSetValues v(_leftBranchValues) ; v() ; ++v) {
ia << v.val();
}
ia << choiceVal;
_leftBranchValues = IntSet(ia);
// Post the branching constraint.
ExecStatus fromBase = ViewValBrancher<View,n,Val,a,Filter,Print>
::commit(home, c, b);
GECODE_ES_CHECK(fromBase);
for (int i = 0 ; i < this->_nsyms ; i++)
this->_syms[i]->update(Literal(choicePos, choiceVal));
} else if (b == 1) {
// Post the branching constraint.
ExecStatus fromBase = ViewValBrancher<View,n,Val,a,Filter,Print>
::commit(home, c, b);
GECODE_ES_CHECK(fromBase);
// Post prunings.
int nliterals = pvc.nliterals();
const Literal* literals = pvc.literals();
for (int i = 0 ; i < nliterals ; i++) {
const Literal& l = literals[i];
ModEvent me = prune<View>(home, this->x[l._variable], l._value);
GECODE_ME_CHECK(me);
}
}
return ES_OK;
}
template<class View, int n, class Val, unsigned int a,
class Filter, class Print>
Actor*
LDSBSetBrancher<View,n,Val,a,Filter,Print>::copy(Space& home) {
return new (home) LDSBSetBrancher<View,n,Val,a,Filter,Print>
(home,*this);
}
template<class View, int n, class Val, unsigned int a,
class Filter, class Print>
forceinline void
LDSBSetBrancher<View,n,Val,a,Filter,Print>::
post(Home home, ViewArray<View>& x,
ViewSel<View>* vs[n], ValSelCommitBase<View,Val>* vsc,
SymmetryImp<View>** syms, int nsyms,
BranchFilter<typename LDSBSetBrancher<View,n,Val,a,Filter,Print>::Var> bf,
VarValPrint<typename LDSBSetBrancher<View,n,Val,a,Filter,Print>::Var,Val> vvp) {
(void) new (home) LDSBSetBrancher<View,n,Val,a,Filter,Print>
(home,x,vs,vsc,syms,nsyms,bf,vvp);
}
template<class View, int n, class Val, unsigned int a>
forceinline void
postldsbsetbrancher(Home home,
ViewArray<View>& x,
ViewSel<View>* vs[n],
ValSelCommitBase<View,Val>* vsc,
SymmetryImp<View>** syms, int nsyms,
BranchFilter<typename View::VarType> bf,
VarValPrint<typename View::VarType,Val> vvp) {
if (bf) {
if (vvp) {
LDSBSetBrancher<View,n,Val,a,BrancherFilter<View>,BrancherPrint<View,Val> >
::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
} else {
LDSBSetBrancher<View,n,Val,a,BrancherFilter<View>,BrancherNoPrint<View,Val> >
::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
}
} else {
if (vvp) {
LDSBSetBrancher<View,n,Val,a,BrancherNoFilter<View>,BrancherPrint<View,Val> >
::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
} else {
LDSBSetBrancher<View,n,Val,a,BrancherNoFilter<View>,BrancherNoPrint<View,Val> >
::post(home,x,vs,vsc,syms,nsyms,bf,vvp);
}
}
}
}}}
// STATISTICS: set-branch