private static void TopologicalSort(string name, Surf.Set dependencyGraph, Surf.Tuple topologicalSort)
{
Surf.Set completed = new Surf.Set();
completed.Add(name);
while (dependencyGraph.Count > 0)
{
for (int i = 0; i < dependencyGraph.Count; i++)
{
Surf.Tuple tuple = (Surf.Tuple)dependencyGraph[i];
if (((Surf.Set)tuple[1]).Difference(completed).Count == 0)
{
topologicalSort.Add(tuple[0]);
completed.Add(tuple[0]);
dependencyGraph.Remove(i);
break;
}
}
}
}
// Hopcroft's Algorithm
public static FiniteAutomaton Minimize(FiniteAutomaton dfa)
{
System.Console.WriteLine("START Minimize " + System.DateTime.Now.ToString());
Surf.Set dfa_transitions = Set(dfa.Transitions);
// Split final states and non-final states.
Surf.Set worklist = new Surf.Set();
Surf.Set P = new Surf.Set();
Surf.Set f = SplitFinalStates(dfa.Tokens);
foreach (Surf.Set f2 in f)
{
worklist.Add(f2);
P.Add(f2);
}
Surf.Set nonFinalStates = new Surf.Set(dfa.States).Difference(new Surf.Set(dfa.FinalStates));
worklist.Add(nonFinalStates);
P.Add(nonFinalStates);
// While there are more states to split.
while (worklist.Count > 0)
{
Surf.Set p = (Surf.Set)worklist[0];
worklist.Remove(0);
Surf.Set t = Split(p, dfa_transitions, P);
if (t.Count > 1)
{
int i = 0;
foreach (Surf.Set p2 in P)
{
if (p2.Equals(p))
{
P.Remove(i);
break;
}
i++;
}
foreach (Surf.Set t2 in t)
{
worklist.Add(t2);
P.Add(t2);
}
}
}
/*
* // Split final states and non-final states.
* Surf.Set P = new Surf.Set();
* Surf.Set f = SplitFinalStates(dfa.Tokens);
* foreach (Surf.Set f2 in f)
* {
* P.Add(f2);
* }
* P.Add(new Surf.Set(dfa.States).Difference(new Surf.Set(dfa.FinalStates)));
*
* // While there are more states to split.
* bool isChanging = true;
* while (isChanging)
* {
* isChanging = false;
*
* Surf.Set T = new Surf.Set();
* foreach (Surf.Set p in P)
* {
* Surf.Set t = Split(p, dfa_transitions, P);
*
* if (t.Count > 1)
* {
* isChanging = true;
* }
* foreach (Surf.Set t2 in t)
* {
* T.Add(t2);
* }
* }
* P = T;
* }
*/
Surf.Set states = new Surf.Set();
Surf.Set alphabet = new Surf.Set();
Surf.Set transitions = new Surf.Set();
int startState;
Surf.Set finalStates = new Surf.Set();
Surf.Set tokens = new Surf.Set();
Surf.Set P_map = PartitionMap(P);
foreach (int state in dfa.States)
{
states.Add(P_map.Apply(state));
}
alphabet = new Surf.Set(dfa.Alphabet);
foreach (Surf.Tuple transition in dfa_transitions)
{
Surf.Tuple input = (Surf.Tuple)transition[0];
int fromState = (int)P_map.Apply(input[0]);
char character = (char)input[1];
int toState = (int)P_map.Apply(transition[1]);
transitions.Add(new Surf.Tuple(new object[] { new Surf.Tuple(new object[] { fromState, character }), toState }));
}
startState = (int)P_map.Apply(dfa.StartState);
foreach (int state in dfa.FinalStates)
{
finalStates.Add(P_map.Apply(state));
if (!tokens.IsDefined(P_map.Apply(state)))
{
tokens.Add(new Surf.Tuple(new object[] { P_map.Apply(state), Lookup(dfa.Tokens, state) }));
}
}
System.Console.WriteLine("END Minimize " + System.DateTime.Now.ToString());
return(Reorder(new FiniteAutomaton(states, alphabet, transitions, startState, finalStates, tokens)));
}
