public T get(String key)
{
BaseNode <T> branch = this;
char[] chars = key.ToCharArray();
foreach (char aChar in chars)
{
if (branch == null)
{
return(default(T));
}
branch = branch.GetChild(aChar);
}
if (branch == null)
{
return(default(T));
}
// 下面这句可以保证只有成词的节点被返回
if (!(branch.NodeStatus == Status.WORD_END_3 || branch.NodeStatus == Status.WORD_MIDDLE_2))
{
return(default(T));
}
return((T)branch.Value);
}
public BaseNode <T> Transition(char[] path, int begin)
{
BaseNode <T> cur = this;
for (int i = begin; i < path.Length; ++i)
{
cur = cur.GetChild(path[i]);
if (cur == null || cur.NodeStatus == Status.UNDEFINED_0)
{
return(null);
}
}
return(cur);
}
/**
* 前缀查询，通过字符数组来表示字符串可以优化运行速度
*
* @param chars 字符串的字符数组
* @param begin 开始的下标
* @return
*/
public LinkedList <KeyValuePair <String, T> > commonPrefixSearchWithValue(char[] chars, int begin)
{
var result = new LinkedList <KeyValuePair <String, T> >();
StringBuilder sb = new StringBuilder();
BaseNode <T> branch = this;
for (int i = begin; i < chars.Length; ++i)
{
char aChar = chars[i];
branch = branch.GetChild(aChar);
if (branch == null || branch.NodeStatus == Status.UNDEFINED_0)
{
return(result);
}
sb.Append(aChar);
if (branch.NodeStatus == Status.WORD_MIDDLE_2 || branch.NodeStatus == Status.WORD_END_3)
{
result.AddLast(new KeyValuePair <String, T>(sb.ToString(), (T)branch.Value));
}
}
return(result);
}
/**
* 前缀查询
*
* @param key 查询串
* @return 键值对
*/
public Dictionary <string, T> prefixSearch(String key)
{
var entrySet = new Dictionary <String, T>();
StringBuilder sb = new StringBuilder(key.Substring(0, key.Length - 1));
BaseNode <T> branch = this;
char[] chars = key.ToCharArray();
foreach (char aChar in chars)
{
if (branch == null)
{
return(entrySet);
}
branch = branch.GetChild(aChar);
}
if (branch == null)
{
return(entrySet);
}
branch.Walk(sb, entrySet);
return(entrySet);
}
