public void SimplePalTest()
{
var q = new States(3);
var f = new AcceptingStates(q[2]);
var tf = new PushdownTransitionFunction()
{
new PushdownTransition(q[0], 'a', Alphabet.Z, q[0], $"a{Alphabet.Z}"),
new PushdownTransition(q[0], 'b', Alphabet.Z, q[0], $"b{Alphabet.Z}"),
new PushdownTransition(q[0], 'a', 'a', q[0], "aa"),
new PushdownTransition(q[0], 'b', 'b', q[0], "bb"),
new PushdownTransition(q[0], 'b', 'a', q[0], "ba"),
new PushdownTransition(q[0], 'a', 'b', q[0], "ab"),
new PushdownTransition(q[0], 'c', 'a', q[1], "a"),
new PushdownTransition(q[0], 'c', 'b', q[1], "b"),
new PushdownTransition(q[0], 'c', Alphabet.Z, q[1], $"{Alphabet.Z}"),
new PushdownTransition(q[1], 'a', 'a', q[1], Alphabet.EmptyString.ToString()),
new PushdownTransition(q[1], 'b', 'b', q[1], Alphabet.EmptyString.ToString()),
new PushdownTransition(q[1], Alphabet.EmptyString, Alphabet.Z, q[2], Alphabet.Z.ToString())
};
var m = new PushdownAutomaton(q, Alphabet.Abc, new StackAlphabet(Alphabet.Abc), tf, q[0], f);
Assert.True(m.Run("aca"));
Assert.True(m.Run("abacaba"));
Assert.True(m.Run("c"));
Assert.True(m.Run("bacab"));
Assert.False(m.Run("ab"));
Assert.False(m.Run("babb"));
Assert.False(m.Run("acab"));
Assert.False(m.Run("bacba"));
}
public void SimpleReverseWordTestInvalid()
{
var transitions = new [] {
new Transition(new State("S0"), new Symbol("1"), new Symbol("Z0"), new State("Q1"), new Symbol[] { new Symbol("1"), new Symbol("Z0") }),
new Transition(new State("S0"), new Symbol("2"), new Symbol("Z0"), new State("Q1"), new Symbol[] { new Symbol("2"), new Symbol("Z0") }),
new Transition(new State("Q1"), new Symbol("1"), new Symbol("1"), new State("Q1"), new Symbol[] { new Symbol("1"), new Symbol("1") }),
new Transition(new State("Q1"), new Symbol("1"), new Symbol("2"), new State("Q1"), new Symbol[] { new Symbol("1"), new Symbol("2") }),
new Transition(new State("Q1"), new Symbol("2"), new Symbol("1"), new State("Q1"), new Symbol[] { new Symbol("2"), new Symbol("1") }),
new Transition(new State("Q1"), new Symbol("2"), new Symbol("2"), new State("Q1"), new Symbol[] { new Symbol("2"), new Symbol("2") }),
new Transition(new State("Q1"), new Symbol("0"), new Symbol("1"), new State("Q2"), new Symbol[] { new Symbol("1") }),
new Transition(new State("Q1"), new Symbol("0"), new Symbol("2"), new State("Q2"), new Symbol[] { new Symbol("2") }),
new Transition(new State("Q2"), new Symbol("1"), new Symbol("1"), new State("Q2"), new Symbol[] { }),
new Transition(new State("Q2"), new Symbol("2"), new Symbol("2"), new State("Q2"), new Symbol[] { }),
new Transition(new State("Q2"), new Symbol(null), new Symbol("Z0"), new State("F"), new Symbol[] { new Symbol("Z0") }),
};
var automaton = new PushdownAutomaton
{
AcceptingStates = new [] { new State("F") },
StartState = new State("S0"),
Transitions = transitions
};
Assert.Throws <NoTransitionFoundException>(() =>
ProcessInput(automaton, new [] { "1", "2", "2", "1", "1", "0", "1", "1", "2" })
);
}
public void SimpleReverseWordTest()
{
var transitions = new [] {
new Transition(new State("S0"), new Symbol("1"), new Symbol("Z0"), new State("Q1"), new Symbol[] { new Symbol("1"), new Symbol("Z0") }),
new Transition(new State("S0"), new Symbol("2"), new Symbol("Z0"), new State("Q1"), new Symbol[] { new Symbol("2"), new Symbol("Z0") }),
new Transition(new State("Q1"), new Symbol("1"), new Symbol("1"), new State("Q1"), new Symbol[] { new Symbol("1"), new Symbol("1") }),
new Transition(new State("Q1"), new Symbol("1"), new Symbol("2"), new State("Q1"), new Symbol[] { new Symbol("1"), new Symbol("2") }),
new Transition(new State("Q1"), new Symbol("2"), new Symbol("1"), new State("Q1"), new Symbol[] { new Symbol("2"), new Symbol("1") }),
new Transition(new State("Q1"), new Symbol("2"), new Symbol("2"), new State("Q1"), new Symbol[] { new Symbol("2"), new Symbol("2") }),
new Transition(new State("Q1"), new Symbol("0"), new Symbol("1"), new State("Q2"), new Symbol[] { new Symbol("1") }),
new Transition(new State("Q1"), new Symbol("0"), new Symbol("2"), new State("Q2"), new Symbol[] { new Symbol("2") }),
new Transition(new State("Q2"), new Symbol("1"), new Symbol("1"), new State("Q2"), new Symbol[] { }),
new Transition(new State("Q2"), new Symbol("2"), new Symbol("2"), new State("Q2"), new Symbol[] { }),
new Transition(new State("Q2"), new Symbol(null), new Symbol("Z0"), new State("F"), new Symbol[] { new Symbol("Z0") }),
};
var automaton = new PushdownAutomaton
{
AcceptingStates = new [] { new State("F") },
StartState = new State("S0"),
Transitions = transitions
};
ProcessInput(automaton, new [] { "1", "2", "2", "1", "1", "0", "1", "1", "2", "2", "1" });
Assert.True(automaton.IsInAcceptingState);
Assert.Single(automaton.GetStackContents());
}
static void Main(string[] args)
{
string file = "Program.txt";
do
{
Console.Write("File:");
string s = Console.ReadLine();
if (s == "q")
{
break;
}
if (s != "p")
{
file = s;
}
PushdownAutomaton PA = PushdownAutomaton.fromFile(file);
if (PA.FindCycle(out string cc))
{
Console.WriteLine("Найден цикл!!"); Console.WriteLine($"Зацикливающая конфигурация: {cc}");
}
else
{
Console.Write("Input:");
Console.WriteLine(PA.Process(Console.ReadLine()));
Console.ReadKey();
Console.Clear();
}
}while (true);
}
private void ProcessInput(PushdownAutomaton automaton, string[] inputs)
{
foreach (var input in inputs)
{
automaton.Read(new Symbol(input));
}
automaton.Read(new Symbol(null));
}
public void NoTransition_ShouldThrow()
{
var automaton = new PushdownAutomaton
{
StartState = new State("S1")
};
Assert.Throws <NoTransitionFoundException>(() => {
automaton.Read(new Symbol("0"));
});
}
public void ValidTransition_ShouldPushMoveAndEndInAcceptingState()
{
var startState = new State("S1");
var otherState = new State("S2");
var finalState = new State("F");
var pushedSymbol = new Symbol("1");
var inputSymbol = new Symbol("0");
var automaton = new PushdownAutomaton
{
StartState = new State("S1"),
Transitions = new [] {
new Transition(
startState,
inputSymbol,
new Symbol("Z0"),
otherState,
new Symbol[] { pushedSymbol, new Symbol("Z0") }
),
new Transition(
otherState,
inputSymbol,
pushedSymbol,
finalState,
new Symbol[] { }
)
},
AcceptingStates = new [] { finalState }
};
automaton.Read(inputSymbol);
Assert.Equal(otherState, automaton.State);
Assert.Collection(
automaton.GetStackContents(),
actual => Assert.Equal(pushedSymbol, actual),
actual => Assert.Equal(new Symbol("Z0"), actual)
);
Assert.False(automaton.IsInAcceptingState);
automaton.Read(inputSymbol);
Assert.Equal(finalState, automaton.State);
Assert.Collection(
automaton.GetStackContents(),
actual => Assert.Equal(new Symbol("Z0"), actual)
);
Assert.True(automaton.IsInAcceptingState);
}
// {0^n1^n | n >= 0}
public void ZeroNOneNTest()
{
var q = new States(3);
var f = new AcceptingStates(q[0], q[2]);
var tf = new PushdownTransitionFunction()
{
new PushdownTransition(q[0], '0', Alphabet.Z, q[0], $"0{Alphabet.Z}"),
new PushdownTransition(q[0], '0', '0', q[0], "00"),
new PushdownTransition(q[0], '1', '0', q[1], new [] { Alphabet.EmptyString }),
new PushdownTransition(q[1], '1', '0', q[1], new [] { Alphabet.EmptyString }),
new PushdownTransition(q[1], Alphabet.EmptyString, Alphabet.Z, q[2], new [] { Alphabet.Z })
};
var m = new PushdownAutomaton(q, Alphabet.Binary, new StackAlphabet(Alphabet.Binary), tf, q[0], f);
Assert.True(m.Run(""));
Assert.True(m.Run("0011"));
Assert.True(m.Run("01"));
Assert.True(m.Run("0000011111"));
Assert.False(m.Run("011010"));
Assert.False(m.Run("101010001"));
Assert.False(m.Run("111000"));
}
/// <summary>
/// Converts source code string into well formed S-Expressions.
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
public static IReadOnlyList <SExpression> Read(IEnumerable <char> input)
{
PushdownAutomaton pda = new PushdownAutomaton();
// Process input char stream
foreach (var ch in input)
{
switch (pda.CurrentState)
{
case PushdownAutomaton.State.Listening:
if (Utils.IsLeftBracket(ch))
{
pda.Push();
}
else if (Utils.IsRightBracket(ch))
{
pda.PopAndCheck();
}
else if (char.IsWhiteSpace(ch))
{
// do nothing
}
else if (ch == ';')
{
pda.CurrentState = PushdownAutomaton.State.Comment;
}
else if (ch == '\"')
{
pda.AppendCharToCache(ch);
pda.CurrentState = PushdownAutomaton.State.String;
}
else
{
pda.AppendCharToCache(ch);
pda.CurrentState = PushdownAutomaton.State.Symbol;
}
break;
case PushdownAutomaton.State.Symbol:
if (Utils.IsLeftBracket(ch))
{
pda.AddAndClearCache();
pda.Push();
pda.CurrentState = PushdownAutomaton.State.Listening;
}
else if (Utils.IsRightBracket(ch))
{
pda.AddAndClearCache();
pda.PopAndCheck();
pda.CurrentState = PushdownAutomaton.State.Listening;
}
else if (char.IsWhiteSpace(ch))
{
pda.AddAndClearCache();
pda.CurrentState = PushdownAutomaton.State.Listening;
}
else if (ch == ';')
{
pda.AddAndClearCache();
pda.CurrentState = PushdownAutomaton.State.Comment;
}
else if (ch == '\"')
{
pda.AddAndClearCache();
pda.AppendCharToCache(ch);
pda.CurrentState = PushdownAutomaton.State.String;
}
else
{
pda.AppendCharToCache(ch);
}
break;
case PushdownAutomaton.State.String:
if (ch == '\"')
{
pda.AppendCharToCache(ch);
pda.AddAndClearCache();
pda.CurrentState = PushdownAutomaton.State.Listening;
}
else
{
pda.AppendCharToCache(ch);
}
break;
case PushdownAutomaton.State.Comment:
if (ch == '\n')
{
pda.CurrentState = PushdownAutomaton.State.Listening;
}
break;
default:
throw new ArgumentException($"Unknown state: {pda.CurrentState}");
}
}
// Process the EOF
if (pda.CurrentState == PushdownAutomaton.State.Symbol)
{
pda.AddAndClearCache();
}
else if (pda.CurrentState == PushdownAutomaton.State.String)
{
throw new ScannerErrorException("Unclosed string");
}
return(pda.CheckAndReturn());
}