ItemTreePtr AtomRemovalSolver::compute()
{
const auto nodeStackElement = app.getPrinter().visitNode(decomposition);
assert(decomposition.getChildren().size() == 1);
Decomposition& childNode = **decomposition.getChildren().begin();
ItemTreePtr childResult = childNode.getSolver().compute();
ItemTreePtr result;
if(childResult) {
result = extendRoot(childResult);
assert(childResult->getChildren().empty() == false);
// Guess node to extend at depth 1
for(const ItemTreePtr& childCandidate : childResult->getChildren()) {
ItemTreeNode::Items candidateItems = childCandidate->getNode()->getItems();
candidateItems.erase(removedAtom);
ItemTreeNode::Items candidateAuxItems = childCandidate->getNode()->getAuxItems();
ItemTreePtr candidate = extendCandidate(std::move(candidateItems), std::move(candidateAuxItems), childCandidate);
for(const ItemTreePtr& childCertificate : childCandidate->getChildren()) {
ItemTreeNode::Items certificateItems = childCertificate->getNode()->getItems();
certificateItems.erase(removedAtom);
ItemTreeNode::Items certificateAuxItems = childCertificate->getNode()->getAuxItems();
const ItemTreeNode::Type type = decomposition.isRoot() ? (certificateAuxItems.find(String("smaller")) == certificateAuxItems.end() ? ItemTreeNode::Type::ACCEPT : ItemTreeNode::Type::REJECT) : ItemTreeNode::Type::UNDEFINED;
candidate->addChildAndMerge(extendCertificate(std::move(certificateItems), std::move(certificateAuxItems), childCertificate, type));
}
result->addChildAndMerge(std::move(candidate));
}
if(result->finalize(app, decomposition.isRoot(), app.isPruningDisabled() == false || decomposition.isRoot()) == false)
result.reset();
}
app.getPrinter().solverInvocationResult(decomposition, result.get());
return result;
}
void Solver::handleRowCandidate(long costBound)
{
// ++models;
assert(asyncResult);
const Clasp::Model& m = asyncResult->model();
// Get items {{{
ItemTreeNode::Items items;
asp_utils::forEachTrue(m, itemAtomInfos, [&items](const GringoOutputProcessor::ItemAtomArguments& arguments) {
items.insert(arguments.item);
});
ItemTreeNode::Items auxItems;
asp_utils::forEachTrue(m, auxItemAtomInfos, [&auxItems](const GringoOutputProcessor::AuxItemAtomArguments& arguments) {
auxItems.insert(arguments.item);
});
ASP_CHECK(std::find_if(items.begin(), items.end(), [&auxItems](const String& item) {
return auxItems.find(item) != auxItems.end();
}) == items.end(), "Items and auxiliary items not disjoint");
// }}}
// FIXME Do proper cost computations, not this item-set cardinality proof of concept
// Compute cost {{{
// ASP_CHECK(asp_utils::countTrue(m, costAtomInfos) <= 1, "More than one true cost/1 atom");
// long cost = 0;
// asp_utils::forFirstTrue(m, costAtomInfos, [&cost](const GringoOutputProcessor::CostAtomArguments& arguments) {
// cost = arguments.cost;
// });
// node->setCost(cost);
long cost = items.size();
for(const auto& row : getCurrentRowCombination()) {
const auto& oldItems = row->getItems();
ItemTreeNode::Items intersection;
std::set_intersection(items.begin(), items.end(), oldItems.begin(), oldItems.end(), std::inserter(intersection, intersection.begin()));
cost += row->getCost() - intersection.size();
}
// }}}
if(cost >= costBound) {
// ++discardedModels;
newestRow = itemTree->getChildren().end();
return;
}
assert(itemTree);
// Create item tree node {{{
std::shared_ptr<ItemTreeNode> node(new ItemTreeNode(std::move(items), std::move(auxItems), {getCurrentRowCombination()}));
// }}}
if(!app.isOptimizationDisabled()) {
// Set cost {{{
node->setCost(cost);
// }}}
// Set current cost {{{
// ASP_CHECK(asp_utils::countTrue(m, currentCostAtomInfos) <= 1, "More than one true currentCost/1 atom");
// ASP_CHECK(asp_utils::countTrue(m, currentCostAtomInfos) == 0 || asp_utils::countTrue(m, costAtomInfos) == 1, "True currentCost/1 atom without true cost/1 atom");
// long currentCost = 0;
// asp_utils::forFirstTrue(m, currentCostAtomInfos, [¤tCost](const GringoOutputProcessor::CurrentCostAtomArguments& arguments) {
// currentCost = arguments.currentCost;
// });
// node->setCurrentCost(currentCost);
node->setCurrentCost(node->getItems().size());
// }}}
// Possibly update cost of root {{{
itemTree->getNode()->setCost(std::min(itemTree->getNode()->getCost(), cost));
// }}}
}
// Add node to item tree {{{
//ItemTree::Children::const_iterator newChild = itemTree->addChildAndMerge(ItemTree::ChildPtr(new ItemTree(std::move(node))));
newestRow = itemTree->costChangeAfterAddChildAndMerge(ItemTree::ChildPtr(new ItemTree(std::move(node))));
// }}}
//if(newChild != itemTree->getChildren().end())
// newestRow = newChild;
}