/**
* Inserts a pair of disjoint elements. Determines whether they can be used to reorder existing sets of lables.
* @param a : One part of pair
* @param b : Other part of pair
* @return : true if a new cluster was required for the insertion.
*/
bool insert(const DisjointElement& a, const DisjointElement& b)
{
const size_t& aLabel = a.getRoot();
const size_t& bLabel = b.getRoot();
bool newItem = true;
GroupType containingAny;
GroupType containingNone;
// ------------- Find equivalent sets
for(GroupType::iterator i = m_groups.begin(); i != m_groups.end(); ++i)
{
GroupType::value_type& cluster =*i;
if(cluster.find(aLabel) != cluster.end())
{
containingAny.push_back(cluster);
}
else if(cluster.find(bLabel) != cluster.end())
{
containingAny.push_back(cluster);
}
else
{
containingNone.push_back(cluster); // Current iterated set contains NEITHER of these labels. It can therfore be ignored.
}
}
// ------------ Process equivalent sets
if(containingAny.empty())
{
// Neither label is yet known to any set. We must add a new set for these
GroupType::value_type newSet;
newSet.insert(aLabel);
newSet.insert(bLabel);
m_groups.push_back(newSet);
}
else
{
// At least one set already contains at least one label. We merge all such sets into a master set.
// implement copy and swap. Rebuild the sets.
GroupType temp = containingNone;
GroupType::value_type masterSet;
masterSet.insert(aLabel); // Incase it doesn't already contain a
masterSet.insert(bLabel); // Incase it doesn't already contain b
for(auto i = containingAny.begin(); i != containingAny.end(); ++i)
{
GroupType::value_type& childSet = *i;
masterSet.insert(childSet.begin(), childSet.end()); // Build the master set.
}
temp.push_back(masterSet);
m_groups = temp; // Swap.
newItem = false;
}
return newItem;
}
/**
* Make composite clusters from the merged groups.
* @return Merged composite clusters.
*/
std::list<boost::shared_ptr<CompositeCluster> > makeCompositeClusters()
{
std::list<boost::shared_ptr<CompositeCluster> > composites;
for(auto i = m_groups.begin(); i != m_groups.end(); ++i)
{
GroupType::value_type& labelSet = *i;
auto composite = boost::make_shared<CompositeCluster>();
for(auto j = labelSet.begin(); j != labelSet.end(); ++j)
{
boost::shared_ptr<ICluster>& cluster = m_register[(*j)];
composite->add(cluster);
}
composites.push_back(composite);
}
return composites;
}
