private void LoadNPDA_Click(object sender, EventArgs e)
{
NPDA = null;
try
{
NPDA = new NPDA(NPDAPath.Text);
MessageBox.Show("Your Input Text Parsed and NPDA Generated Successfully", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
}
catch (Exception exception)
{
MessageBox.Show(exception.Message, "Failed!", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
public CFG(NPDA npda)
{
if (npda.FinalStates.Count != 1)
{
throw new Exception("Can not convert this NPDA to CFG beacuase it has more than 1 final state!");
}
NumberToVariable = new List <string>();
Transitions = new List <Tuple <List <char>, List <int>, List <int> > >();
string leftSide;
string rightSide1;
string rightSide2;
int indexOfLeftSide;
int indexOfRightSide1;
int indexOfRightSide2;
for (int source = 0; source < npda.Transitions.Length; source++)
{
var transition = npda.Transitions[source];
for (int i = 0; i < transition.Item4.Count; i++)
{
if (transition.Item4[i] == "_")
{
leftSide = string.Format("(q{0}{1}q{2})", source, transition.Item3[i], transition.Item1[i]);
indexOfLeftSide = NumberToVariable.IndexOf(leftSide);
if (indexOfLeftSide != -1)
{
Transitions[indexOfLeftSide].Item1.Add(transition.Item2[i]);
Transitions[indexOfLeftSide].Item2.Add(-1);
Transitions[indexOfLeftSide].Item3.Add(-1);
}
else
{
NumberToVariable.Add(leftSide);
indexOfLeftSide = Transitions.Count;
Transitions.Add(new Tuple <List <char>, List <int>, List <int> >
(new List <char>(), new List <int>(), new List <int>()));
Transitions[indexOfLeftSide].Item1.Add(transition.Item2[i]);
Transitions[indexOfLeftSide].Item2.Add(-1);
Transitions[indexOfLeftSide].Item3.Add(-1);
}
if (source == npda.InitialState &&
transition.Item3[i] == npda.StackInitialSymbol &&
transition.Item1[i] == npda.FinalStates[0]) //We should only have one final state
{
StartVariable = indexOfLeftSide;
}
}
else
{
for (int l = 0; l < npda.StateCount; l++)
{
for (int k = 0; k < npda.StateCount; k++)
{
leftSide = string.Format("(q{0}{1}q{2})", source, transition.Item3[i], k);
rightSide1 = string.Format("(q{0}{1}q{2})", transition.Item1[i], transition.Item4[i][0], l);
rightSide2 = string.Format("(q{0}{1}q{2})", l, transition.Item4[i][1], k);
indexOfRightSide1 = NumberToVariable.IndexOf(rightSide1);
if (indexOfRightSide1 == -1)
{
indexOfRightSide1 = NumberToVariable.Count;
NumberToVariable.Add(rightSide1);
Transitions.Add(new Tuple <List <char>, List <int>, List <int> >
(new List <char>(), new List <int>(), new List <int>()));
}
if (source == npda.InitialState &&
transition.Item3[i] == npda.StackInitialSymbol &&
k == npda.FinalStates[0]) //We should only have one final state
{
StartVariable = indexOfRightSide1;
}
indexOfRightSide2 = NumberToVariable.IndexOf(rightSide2);
if (indexOfRightSide2 == -1)
{
indexOfRightSide2 = NumberToVariable.Count;
NumberToVariable.Add(rightSide2);
Transitions.Add(new Tuple <List <char>, List <int>, List <int> >
(new List <char>(), new List <int>(), new List <int>()));
}
if (transition.Item1[i] == npda.InitialState &&
transition.Item4[i][0] == npda.StackInitialSymbol &&
l == npda.FinalStates[0]) //We should only have one final state
{
StartVariable = indexOfRightSide2;
}
indexOfLeftSide = NumberToVariable.IndexOf(leftSide);
if (indexOfLeftSide != -1)
{
Transitions[indexOfLeftSide].Item1.Add(transition.Item2[i]);
Transitions[indexOfLeftSide].Item2.Add(indexOfRightSide1);
Transitions[indexOfLeftSide].Item3.Add(indexOfRightSide2);
}
else
{
NumberToVariable.Add(leftSide);
Transitions.Add(new Tuple <List <char>, List <int>, List <int> >
(new List <char>(), new List <int>(), new List <int>()));
Transitions[Transitions.Count - 1].Item1.Add(transition.Item2[i]);
Transitions[Transitions.Count - 1].Item2.Add(indexOfRightSide1);
Transitions[Transitions.Count - 1].Item3.Add(indexOfRightSide2);
}
if (l == npda.InitialState &&
transition.Item4[i][1] == npda.StackInitialSymbol &&
k == npda.FinalStates[0]) //We should only have one final state
{
StartVariable = indexOfLeftSide;
}
}
}
}
}
}
}
