/// <summary>
/// Searches passed text and returns first occurrence of any keyword
/// </summary>
/// <param name="text">Text to search</param>
/// <returns>First occurrence of any keyword (or StringSearchResult.Empty if text doesn't contain any keyword)</returns>
//public StringSearchResult FindFirst(string text)
//{
// TreeCharNode ptr = Root;
// int index = 0;
// while (index < text.Length)
// {
// TreeCharNode trans = null;
// while (trans == null)
// {
// trans = ptr.Children.ContainsKey(text[index]) ? ptr.Children[text[index]] : null;
// if (ptr == Root)
// break;
// if (trans == null)
// ptr = ptr.Failure;
// }
// if (trans != null)
// ptr = trans;
// foreach (string found in ptr.Words)
// return new StringSearchResult(index - found.Length + 1, found);
// index++;
// }
// return new StringSearchResult(-1, "");
//}
/// <summary>
/// Searches passed text and returns true if text contains any keyword
/// </summary>
/// <param name="text">Text to search</param>
/// <returns>True when text contains any keyword</returns>
public bool ContainsAny(string text)
{
TreeCharNode ptr = Root;
int index = 0;
while (index < text.Length)
{
TreeCharNode trans = null;
while (trans == null)
{
trans = ptr.Children.ContainsKey(text[index]) ? ptr.Children[text[index]] : null;
if (ptr == Root)
{
break;
}
if (trans == null)
{
ptr = ptr.Failure;
}
}
if (trans != null)
{
ptr = trans;
}
if (ptr.Words.Any())
{
return(true);
}
index++;
}
return(false);
}
/// <summary>
/// Searches passed text and returns all occurrences of any keyword
/// </summary>
/// <param name="text">Text to search</param>
/// <returns>Array of occurrences</returns>
public List <StringSearchResult> FindAll(string text)
{
var ret = new List <StringSearchResult>();
TreeCharNode ptr = Root;
int index = 0;
while (index < text.Length)
{
TreeCharNode trans = null;
while (trans == null)
{
trans = ptr.Children.ContainsKey(text[index]) ? ptr.Children[text[index]] : null;
if (ptr == Root)
{
break;
}
if (trans == null)
{
ptr = ptr.Failure;
}
}
if (trans != null)
{
ptr = trans;
}
foreach (string found in ptr.Words)
{
ret.Add(new StringSearchResult(index - found.Length + 1, found));
}
index++;
}
return(ret);
}
private void BuildTree(List <string> words)
{
Root = new TreeCharNode(' ');
foreach (string w in words)
{
TreeCharNode nd = Root;
foreach (char c in w)
{
TreeCharNode ndNew = null;
if (nd.Children.ContainsKey(c))
{
ndNew = nd.Children[c];
}
if (ndNew == null)
{
ndNew = new TreeCharNode(c, nd);
nd.Children.Add(c, ndNew);
}
nd = ndNew;
}
nd.Words.Add(w);
}
// Find failure functions
Queue <TreeCharNode> nodes = new Queue <TreeCharNode>();
// level 1 nodes - fail to root node
foreach (TreeCharNode nd in Root.Children.Values)
{
nd.Failure = Root;
foreach (TreeCharNode trans in nd.Children.Values)
{
nodes.Enqueue(trans);
}
}
// other nodes - using BFS
while (nodes.Any())
{
TreeCharNode nd = nodes.Dequeue();
TreeCharNode r = nd.Parent.Failure;
while (r != null && !r.Children.ContainsKey(nd.Id))
{
r = r.Failure;
}
if (r == null)
{
nd.Failure = Root;
}
else
{
nd.Failure = r.Children[nd.Id];
foreach (string word in nd.Failure.Words)
{
nd.Words.Add(word);
}
}
foreach (TreeCharNode child in nd.Children.Values)
{
nodes.Enqueue(child);
}
}
Root.Failure = Root;
}
public TreeCharNode(char id, TreeCharNode parent) : this(id)
{
Parent = parent;
}
