public DiaGraphAPI BuildEpsilonTransitionDiGraph()
{
DiaGraphAPI G = new DiaGraphAPI(M + 1);
Stack <int> ops = new Stack <int>();
for (int i = 0; i < M; i++)
{
int lp = i;
if (re[i] == '(' || re[i] == '|')
{
ops.Push(i);
}
else if (re[i] == ')')
{
int or = ops.Pop();
if (re[or] == '|')
{
lp = ops.Pop();
G.AddEdge(lp, or + 1);
G.AddEdge(or, i);
}
else
{
lp = or;
}
}
if (i < M - 1 && re[i + 1] == '*')
{
G.AddEdge(lp, i + 1);
G.AddEdge(i + 1, lp);
}
if (re[i] == '(' || re[i] == '*' || re[i] == ')')
{
G.AddEdge(i, i + 1);
}
}
return(G);
}
public NFA(string regExp)
{
M = regExp.Length;
re = regExp.ToCharArray();
G = BuildEpsilonTransitionDiGraph();
}