/// <summary>
/// 添加节点
/// </summary>
/// <param name="node">过度的几点</param>
public void AddTransition(KeyWordTreeNode node)
{
_transHash.Add(node.Char, node);
KeyWordTreeNode[] ar = new KeyWordTreeNode[_transHash.Values.Count];
_transHash.Values.CopyTo(ar, 0);
_transitionsAr = ar;
}
/// <summary>
/// 是否包含
/// </summary>
/// <param name="text">要搜索的文本</param>
/// <returns>是否包含关键词</returns>
public bool ContainsAny(string text)
{
KeyWordTreeNode ptr = _root;
for (int i = 0; i < text.Length; i++)
{
KeyWordTreeNode trans = null;
while (trans == null)
{
trans = ptr.GetTransition(text[i]);
if (ptr == _root)
{
break;
}
if (trans == null)
{
ptr = ptr.Failure;
}
}
if (trans != null)
{
ptr = trans;
if (ptr.Results.Length > 0)
{
return(true);
}
}
}
return(false);
}
/// <summary>
/// 搜索第一个关键词
/// </summary>
/// <param name="text">要搜索的文本</param>
/// <returns>搜索到的对象</returns>
public KeyWordModel FindFirst(string text)
{
ArrayList ret = new ArrayList();
KeyWordTreeNode ptr = _root;
for (int i = 0; i < text.Length; i++)
{
KeyWordTreeNode trans = null;
while (trans == null)
{
trans = ptr.GetTransition(text[i]);
if (ptr == _root)
{
break;
}
if (trans == null)
{
ptr = ptr.Failure;
}
}
if (trans != null)
{
ptr = trans;
foreach (string found in ptr.Results)
{
return(new KeyWordModel(i - found.Length + 1, found));
}
}
}
return(KeyWordModel.Empty);
}
/// <summary>
/// 构造函数
/// </summary>
/// <param name="parent">父节点</param>
/// <param name="c">字符</param>
public KeyWordTreeNode(KeyWordTreeNode parent, char c)
{
_char = c; _parent = parent;
_results = new ArrayList();
_resultsAr = new string[] { };
_transitionsAr = new KeyWordTreeNode[] { };
_transHash = new Hashtable();
}
/// <summary>
/// 生成树
/// </summary>
private void BuildTree()
{
_root = new KeyWordTreeNode(null, ' ');
#region 生成树
foreach (string p in _keywords)
{
KeyWordTreeNode nd = _root;
foreach (char c in p)
{
KeyWordTreeNode ndNew = null;
foreach (KeyWordTreeNode trans in nd.Transitions)
{
if (trans.Char == c)
{
ndNew = trans;
break;
}
}
if (ndNew == null)
{
ndNew = new KeyWordTreeNode(nd, c);
nd.AddTransition(ndNew);
}
nd = ndNew;
}
nd.AddResult(p);
}
#endregion
ArrayList nodes = new ArrayList();
//第一层失败节点
foreach (KeyWordTreeNode nd in _root.Transitions)
{
nd.Failure = _root;
foreach (KeyWordTreeNode trans in nd.Transitions)
{
nodes.Add(trans);
}
}
//下级失败节点
while (nodes.Count != 0)
{
ArrayList newNodes = new ArrayList();
foreach (KeyWordTreeNode nd in nodes)
{
KeyWordTreeNode r = nd.Parent.Failure;
char c = nd.Char;
while (r != null && !r.ContainsTransition(c))
{
r = r.Failure;
}
if (r == null)
{
nd.Failure = _root;
}
else
{
nd.Failure = r.GetTransition(c);
foreach (string result in nd.Failure.Results)
{
nd.AddResult(result);
}
}
//添加子节点在失败节点中
foreach (KeyWordTreeNode child in nd.Transitions)
{
newNodes.Add(child);
}
}
nodes = newNodes;
}
_root.Failure = _root;
}
