public StateMachine(StateGraph stateGraph)
{
Graph = stateGraph
?? throw new ArgumentNullException(nameof(stateGraph));
_currentNode = stateGraph.Root;
Symbol = StateGraph.DefaultSymbol;
}
public static string PrintGraphExpression(this StateGraph graph)
{
var sb = new StringBuilder(1000);
var visitedNodes = new HashSet <StateGraph.Node>();
PrintGraphExpressionRecursive(graph.Root, sb, visitedNodes);
return(sb.ToString());
}
public static string PrintTrivialGraphFormat(this StateGraph graph, string separator = null)
{
separator = separator ?? Environment.NewLine;
var traversalNodes = new LinkedList <StateGraph.Node>();
var visitedNodes = new HashSet <StateGraph.Node>();
var root = graph.Root;
traversalNodes.AddLast(root);
var nodesPrint = new LinkedList <string>();
var transitionsPrint = new LinkedList <string>();
while (traversalNodes.NotEmpty())
{
var currentNode = traversalNodes.GetRemoveFirst();
if (visitedNodes.Contains(currentNode))
{
continue;
}
var t = currentNode.Transitions;
nodesPrint.AddLast($"{currentNode.NodeIndex} {currentNode.PrintCore()}");
for (int i = 0; i < t.Length; ++i)
{
var transitionNode = t[i];
if (transitionNode == null)
{
continue;
}
transitionsPrint.AddLast($"{currentNode.NodeIndex} {transitionNode.NodeIndex} {i}");
if (visitedNodes.Contains(transitionNode))
{
continue;
}
traversalNodes.AddLast(transitionNode);
}
visitedNodes.Add(currentNode);
}
return(string.Join(separator, nodesPrint.Concat(Enumerable.Repeat("#", 1)).Concat(transitionsPrint)));
}
public static int[] ToTransitionMatrix(this StateGraph graph)
{
var alphabetSize = graph.AlphabetSize;
var nodeCount = graph.StateCount;
if (nodeCount < alphabetSize + 1)
{
throw new InvalidOperationException("The graph is underpopulated with nodes");
}
var result = new int[alphabetSize * nodeCount];
var traversalNodes = new LinkedList <StateGraph.Node>();
var visitedNodes = new HashSet <StateGraph.Node>();
var root = graph.Root;
traversalNodes.AddLast(root);
while (traversalNodes.NotEmpty())
{
var currentNode = traversalNodes.GetRemoveFirst();
if (visitedNodes.Contains(currentNode))
{
continue;
}
var t = currentNode.Transitions;
var currentNodeIndex = currentNode.NodeIndex;
var rowFirstIndex = currentNode.NodeIndex * alphabetSize;
for (int i = 0; i < t.Length; ++i)
{
var transitionNode = t[i];
if (transitionNode == null)
{
throw new InvalidOperationException($"Transition {i} is absent in node {currentNodeIndex}");
}
result[rowFirstIndex + i] = transitionNode.NodeIndex;
if (visitedNodes.Contains(transitionNode))
{
continue;
}
traversalNodes.AddLast(transitionNode);
}
visitedNodes.Add(currentNode);
if (visitedNodes.Count == nodeCount)
{
return(result);
}
}
return(result);
}
public static void WriteInMissingTransitions(this StateGraph graph) => WriteInMissingTransitions(graph.Root, graph, new List <int>());
public static void WriteInMissingSequenceIndices(this StateGraph graph) => WriteInMissingSequenceIndices(graph.Root, graph, new List <int>());
public static void BuildTrie(this StateGraph graph, int[][] sequences)
{
if (sequences == null)
{
throw new ArgumentNullException(nameof(sequences));
}
var root = graph.Root;
var nodeIndex = 1;
var sequenceIndex = 1;
var alphabetSize = graph.AlphabetSize;
for (int i = 0; i < alphabetSize; ++i)
{
root.Transitions[i] = new StateGraph.Node(alphabetSize, nodeIndex++)
{
SequenceIndex = sequenceIndex++
}
}
;
for (int k = 0; k < sequences.Length; ++k)
{
var sequence = sequences[k]
?? throw new ArgumentNullException($"sequence {sequenceIndex}");
var lastSymbolIndex = sequence.Length - 1;
if (lastSymbolIndex < 0)
{
throw new ArgumentException($"sequence {sequenceIndex} is empty");
}
var currentNode = root;
for (int j = 0; j <= lastSymbolIndex; ++j)
{
var symbol = sequence[j];
if (symbol >= alphabetSize || symbol < 0)
{
throw new ArgumentException($"symbol {symbol} at index {j} of sequence {sequenceIndex} is out of the boundaries of the alphabet");
}
var t = currentNode.Transitions;
StateGraph.Node childNode = t[symbol];
if (childNode == null)
{
childNode = new StateGraph.Node(alphabetSize, nodeIndex++);
t[symbol] = childNode;
}
if (j == lastSymbolIndex)
{
if (childNode.SequenceIndex == -1)
{
childNode.SequenceIndex = sequenceIndex++;
}
else
{
throw new ArgumentException($"sequence {sequenceIndex} is equal to sequence {childNode.SequenceIndex}");
}
}
currentNode = childNode;
}
}
graph.StateCount = nodeIndex;
}