// Add a node to the heap
void
CbcTree::push(CbcNode * x)
{
x->setNodeNumber(maximumNodeNumber_);
maximumNodeNumber_++;
# if CBC_DEBUG_HEAP > 2
CbcNodeInfo *info = x->nodeInfo() ;
assert(info) ;
std::cout
<< " HEAP: Pushing node " << x->nodeNumber()
<< "(" << std::hex << x << std::dec << ") obj " << x->objectiveValue()
<< ", ref " << info->decrement(0)
<< ", todo " << info->numberBranchesLeft()
<< ", refd by " << info->numberPointingToThis() << "." << std::endl ;
assert(x->objectiveValue() != COIN_DBL_MAX);
# endif
# if CBC_DEBUG_HEAP > 0
validateHeap() ;
# endif
x->setOnTree(true);
nodes_.push_back(x);
std::push_heap(nodes_.begin(), nodes_.end(), comparison_);
# if CBC_DEBUG_HEAP > 0
validateHeap() ;
# endif
}
// Remove the top node from the heap
void
CbcTree::pop()
{
# if CBC_DEBUG_HEAP > 2
CbcNode *node = nodes_.front() ;
CbcNodeInfo *info = node->nodeInfo() ;
assert(info) ;
std::cout
<< " HEAP: Popping node " << node->nodeNumber()
<< "(" << std::hex << node << std::dec
<< ") obj " << node->objectiveValue()
<< ", ref " << info->decrement(0)
<< ", todo " << info->numberBranchesLeft()
<< ", refd by " << info->numberPointingToThis() << "." << std::endl ;
# endif
# if CBC_DEBUG_HEAP > 0
validateHeap() ;
# endif
nodes_.front()->setOnTree(false);
std::pop_heap(nodes_.begin(), nodes_.end(), comparison_);
nodes_.pop_back();
# if CBC_DEBUG_HEAP > 0
validateHeap() ;
# endif
}
// First or second branch
CbcStatistics::CbcStatistics(CbcNode * node, CbcModel * model)
: endingObjective_(COIN_DBL_MAX),
endingInfeasibility_(0),
numberIterations_(0)
{
CbcNodeInfo * nodeInfo = node->nodeInfo();
CbcNodeInfo * parent = nodeInfo->parent();
int numberBranches = nodeInfo->numberBranchesLeft();
const CbcBranchingObject * branch = dynamic_cast <const CbcBranchingObject *>(node->branchingObject());
const OsiTwoWayBranchingObject * branch2 = dynamic_cast <const OsiTwoWayBranchingObject *>(node->branchingObject());
startingObjective_ = node->objectiveValue();
way_ = node->way();
depth_ = node->depth();
startingInfeasibility_ = node->numberUnsatisfied();
if (branch) {
sequence_ = branch->variable();
value_ = branch->value();
} else {
const OsiSimpleInteger * obj = dynamic_cast<const OsiSimpleInteger *>(branch2->originalObject());
assert (obj);
sequence_ = obj->columnNumber();
value_ = branch2->value();
}
if (parent)
parentId_ = parent->nodeNumber();
else
parentId_ = -1;
if (numberBranches == 2) {
id_ = nodeInfo->nodeNumber();
} else {
way_ *= 10;
id_ = model->getNodeCount2();
}
}
/*
Return the best node from the heap.
Note that best is offered a chance (checkIsCutoff) to reevaluate
itself and make arbitrary changes. A caller should be prepared
to check that the returned node is acceptable.
There's quite a bit of suspect code here, much of it disabled in
some way. The net effect at present is to return the top node on
the heap after offering the node an opportunity to reevaluate itself.
Documentation for checkIsCutoff() puts no restrictions on allowable
changes. -- lh, 100921 --
*/
CbcNode *
CbcTree::bestNode(double cutoff)
{
# if CBC_DEBUG_HEAP > 0
validateHeap() ;
# endif
/*
This code is problematic. As of 100921, there's really no loop.
If front() == null, an assert will trigger. checkIsCutoff seems to be
work in progress; comments assert that it can make pretty much arbitrary
changes to best. If best can change its objective, there's a good
possibility the heap is invalid.
*/
CbcNode * best = NULL;
while (!best && nodes_.size()) {
best = nodes_.front();
if (best)
assert(best->objectiveValue() != COIN_DBL_MAX && best->nodeInfo());
if (best && best->objectiveValue() != COIN_DBL_MAX && best->nodeInfo())
assert (best->nodeInfo()->numberBranchesLeft());
if (best && best->objectiveValue() >= cutoff) {
// double check in case node can change its mind!
best->checkIsCutoff(cutoff);
}
if (!best || best->objectiveValue() >= cutoff) {
#ifdef JJF_ZERO
// take off
std::pop_heap(nodes_.begin(), nodes_.end(), comparison_);
nodes_.pop_back();
delete best;
best = NULL;
#else
// let code get rid of it
assert (best);
#endif
}
}
/*
See if the comparison object wants us to do a full scan with the
alternative criteria. The net effect is to confirm best by the
alternative criteria, or identify a competitor and erase it.
This code is problematic. Nulling an arbitrary node will in general
break the heap property. Disabled some time ago, as noted in several
places.
*/
if (false && best && comparison_.test_->fullScan()) {
CbcNode * saveBest = best;
size_t n = nodes_.size();
size_t iBest = -1;
for (size_t i = 0; i < n; i++) {
// temp
assert (nodes_[i]);
assert (nodes_[i]->nodeInfo());
if (nodes_[i] && nodes_[i]->objectiveValue() != COIN_DBL_MAX && nodes_[i]->nodeInfo())
assert (nodes_[i]->nodeInfo()->numberBranchesLeft());
if (nodes_[i] && nodes_[i]->objectiveValue() < cutoff
&& comparison_.alternateTest(best, nodes_[i])) {
best = nodes_[i];
iBest = i;
}
}
if (best == saveBest) {
// can pop
// take off
std::pop_heap(nodes_.begin(), nodes_.end(), comparison_);
nodes_.pop_back();
} else {
// make impossible
nodes_[iBest] = NULL;
}
} else if (best) {
# if CBC_DEBUG_HEAP > 2
CbcNode *node = nodes_.front() ;
CbcNodeInfo *info = node->nodeInfo() ;
assert(info) ;
std::cout
<< " bestNode: Popping node " << node->nodeNumber()
<< "(" << std::hex << node << std::dec
<< ") obj " << node->objectiveValue()
<< ", ref " << info->decrement(0)
<< ", todo " << info->numberBranchesLeft()
<< ", refd by " << info->numberPointingToThis() << "." << std::endl ;
# endif
// take off
std::pop_heap(nodes_.begin(), nodes_.end(), comparison_);
nodes_.pop_back();
}
#if CBC_DEBUG_HEAP > 0
validateHeap() ;
#endif
if (best)
best->setOnTree(false);
return best;
}
