private void ContainsChain(FiniteStateMachineNode currentNode, FiniteStateMachineNode prevNode,
string key, string[] factors, int iterator, ref bool result)
{
if (!result)
{
if (iterator >= factors.Length)
{
if (!LastNodes.Contains(prevNode))
{
result = false;
}
else
{
result = true;
}
}
else if (key != Helper.IdentitySymbol && factors[iterator] != key)
{
result = false;
}
else
{
foreach (var child in currentNode.ChildrenNodes)
{
ContainsChain(child.Value, currentNode, child.Key, factors, key == Helper.IdentitySymbol ? iterator : iterator + 1, ref result);
}
}
}
}
public FiniteStateMachine(string expression)
{
var summands = SRECoefficient.Split(expression);
Stack <int> leftBracketNodeNumbers = new Stack <int>();
int multiplyPosition, oldPosition;
Nodes = new List <FiniteStateMachineNode>();
int currentNumber = 0;
FirstNode = new FiniteStateMachineNode {
Number = currentNumber++, Symbol = Helper.IdentitySymbol
};
Nodes.Add(FirstNode);
LastNodes = new List <FiniteStateMachineNode>();
foreach (var summand in summands)
{
var currentNode = new FiniteStateMachineNode {
Number = currentNumber++
};
Nodes.Add(currentNode);
FirstNode.ChildrenNodes.Add(new KeyValuePair <string, FiniteStateMachineNode>(FirstNode.Symbol, currentNode));
oldPosition = -1;
bool endState = false;
do
{
multiplyPosition = summand.IndexOf(Helper.Multiply, oldPosition + 1);
if (multiplyPosition == -1)
{
multiplyPosition = summand.Length; // Нужно учесть последнее слагаемое.
}
if (multiplyPosition != -1)
{
if (summand[multiplyPosition - 1] == Helper.IterationSymbol)
{
if (summand[multiplyPosition - 2] == Helper.RightBracket)
{
if (summand[multiplyPosition - 3] == Helper.IterationSymbol)
{
var symbol = summand.Substring(oldPosition + 1, multiplyPosition - oldPosition - 4);
currentNode.ChildrenNodes.Add(new KeyValuePair <string, FiniteStateMachineNode>(symbol, currentNode));
}
else
{
var newNode = new FiniteStateMachineNode {
Number = currentNumber++
};
var symbol = summand.Substring(oldPosition + 1, multiplyPosition - oldPosition - 3);
currentNode.ChildrenNodes.Add(new KeyValuePair <string, FiniteStateMachineNode>(symbol, newNode));
Nodes.Add(newNode);
currentNode = newNode;
}
Nodes[leftBracketNodeNumbers.Peek()].ChildrenNodes.Add(new KeyValuePair <string, FiniteStateMachineNode>(Helper.IdentitySymbol, currentNode));
currentNode.ChildrenNodes.Add(new KeyValuePair <string, FiniteStateMachineNode>(
Nodes[leftBracketNodeNumbers.Peek() + 1].Symbol, Nodes[leftBracketNodeNumbers.Pop() + 1]));
if (multiplyPosition == summand.Length)
{
endState = true;
}
}
else
{
// Итерация узла на самого себя.
if (multiplyPosition + 1 < summand.Length && summand[multiplyPosition + 1] == Helper.LeftBracket)
{
// Если следующий символ является скобкой, то нужно ввести дополнительный узел.
var newNode = new FiniteStateMachineNode {
Number = currentNumber++, Symbol = Helper.IdentitySymbol
};
currentNode = newNode;
}
else
{
var symbol = summand.Substring(oldPosition + 1, multiplyPosition - oldPosition - 2);
currentNode.ChildrenNodes.Add(new KeyValuePair <string, FiniteStateMachineNode>(symbol, currentNode));
if (multiplyPosition == summand.Length)
{
endState = true;
}
}
}
}
else
{
// Не итерация.
currentNode.Symbol = summand.Substring(oldPosition + 1, multiplyPosition - oldPosition - 1);
if (multiplyPosition == summand.Length)
{
endState = true;
}
}
if (!endState)
{
if (summand[multiplyPosition + 1] == Helper.LeftBracket)
{
leftBracketNodeNumbers.Push(currentNumber); // Запоминаем номер ноды.
oldPosition = multiplyPosition + 1;
}
else
{
oldPosition = multiplyPosition;
}
if (summand[multiplyPosition - 1] != Helper.IterationSymbol)
{
var newNode = new FiniteStateMachineNode {
Number = currentNumber++
};
currentNode.ChildrenNodes.Add(new KeyValuePair <string, FiniteStateMachineNode>(currentNode.Symbol, newNode));
Nodes.Add(newNode);
currentNode = newNode;
}
}
}
}while (!endState);
LastNodes.Add(currentNode);
}
}
