public static void MainTest(string[] args)
{
// read in digraph from command-line argument
//if (args.Length < 2) throw new ArgumentException("Expecting input file");
TextInput input = new TextInput(args[0]);
Digraph G = new Digraph(input);
// read in sources from command-line arguments
Bag <int> sources = new Bag <int>();
for (int i = 1; i < args.Length; i++)
{
int s = int.Parse(args[i]);
sources.Add(s);
}
// multiple-source reachability
DirectedDFS dfs = new DirectedDFS(G, sources);
// print out vertices reachable from sources
for (int v = 0; v < G.V; v++)
{
if (dfs.Marked(v))
{
Console.Write(v + " ");
}
}
Console.WriteLine();
}
/// <summary>
/// Returns true if the text is matched by the regular expression.</summary>
/// <param name="txt"> txt the text</param>
/// <returns><c>true</c> if the text is matched by the regular expression,
/// <c>false</c> otherwise</returns>
///
public bool Recognizes(string txt)
{
DirectedDFS dfs = new DirectedDFS(G, 0);
Bag <int> pc = new Bag <int>();
for (int v = 0; v < G.V; v++)
{
if (dfs.Marked(v))
{
pc.Add(v);
}
}
// Compute possible NFA states for txt[i+1]
for (int i = 0; i < txt.Length; i++)
{
if (txt[i] == '*' || txt[i] == '|' || txt[i] == '(' || txt[i] == ')')
{
throw new ArgumentException("text contains the metacharacter '" + txt[i] + "'");
}
Bag <int> match = new Bag <int>();
foreach (int v in pc)
{
if (v == M)
{
continue;
}
if ((regexp[v] == txt[i]) || regexp[v] == '.')
{
match.Add(v + 1);
}
}
dfs = new DirectedDFS(G, match);
pc = new Bag <int>();
for (int v = 0; v < G.V; v++)
{
if (dfs.Marked(v))
{
pc.Add(v);
}
}
// optimization if no states reachable
if (pc.Count == 0)
{
return(false);
}
}
// check for accept state
foreach (int v in pc)
{
if (v == M)
{
return(true);
}
}
return(false);
}
private DirectedDFS[] tc; // tc[v] = reachable from v
/// <summary>Computes the transitive closure of the digraph <c>G</c>.</summary>
/// <param name="G">the digraph</param>
///
public TransitiveClosure(Digraph G)
{
tc = new DirectedDFS[G.V];
for (int v = 0; v < G.V; v++)
{
tc[v] = new DirectedDFS(G, v);
}
}
