DFA::DFA(const NFA& nfa)
{
allocPoint(); //create start point
//std::map<std::set<int>, int> sim {{std::set<int>{0}, 0}};
//std::map<int, std::set<int> > ism {{0, std::set<int>{0}}};
//std::unordered_map<dynarray<int>, int, DynarrayHash<int> > n2d;
std::map<std::set<int>, int> n2d;
std::queue<std::set<int> > q;
std::set<int> initClosure {0};
nfa.expandToEpsilonClosure(initClosure);
n2d.emplace(initClosure, 0);
q.push(std::move(initClosure));
while (!q.empty())
{
std::set<int>& s = q.front(); q.pop();
int p = n2d[s];
std::vector<pair<int, int> > v;
for (int sp : s)
{
for (auto& edge : nfa.m_graph[sp])
{
if (edge.first != epsilon)
v.push_back(edge);
}
}
sort(v.begin(), v.end());
if (v.empty())
continue;
pair<int, int> prev = v[0];
std::set<int> ns {prev.second};
for (int i = 1; i <= v.size(); ++i)
{
auto edge = std::make_pair(-1, -1);//a dummy edge never equal to prev
if (i < v.size())
edge = v[i];
if (edge.first != prev.first)
{
int d = -1;
nfa.expandToEpsilonClosure(ns);
if (n2d.count(ns) == 0)
{
d = allocPoint();
n2d.emplace(ns, d);
q.push(std::move(ns));
}
else
d = n2d[ns];
addEdge(p, prev.first, d);
ns.clear();
}
ns.insert(edge.second);
prev = edge;
}
}
}
