trie 的运用

class TTrie {<br />  protected $buffer = array();<br />  protected $dict = array( array() );<br />  protected $input = 0; //字符串当前偏移<br />  protected $backtracking = 0; //字符串回溯位置<br />  public $debug = 0;<br />  public $savematch = 1;<br /><br />  function set($word, $action='') {<br />	if(is_array($word)) {<br />		foreach($word as $k=>$v) $this->set($k, $v);<br />		return;<br />	}<br />	$p = count($this->dict);<br />	$cur = 0; //当前节点号<br />	foreach(str_split($word) as $c) {<br />		if (isset($this->dict[$cur][$c])) { //已存在就下移<br />			$cur = $this->dict[$cur][$c];<br />			continue;<br />		}<br />		$this->dict[$p]= array(); //创建新节点<br />		$this->dict[$cur][$c] = $p; //在父节点记录子节点号<br />		$cur = $p; //把当前节点设为新插入的<br />		$p++;<br />	}<br />	$this->dict[$cur]['acc'] = $action; //一个词结束，标记叶子节点<br />  }<br /><br />  function match($s) {<br />	$ret = array();<br />	$cur = 0; //当前节点，初始为根节点<br />	$i =& $this->input; //字符串当前偏移<br />	$p =& $this->backtracking; //字符串回溯位置<br />	$s .= "\0"; //附加结束符<br />	$len = strlen($s);<br />	$buf = '';<br />	while($i < $len) {<br />		$c = $s{$i};<br />		if(isset($this->dict[$cur][$c])) { //如果存在<br />			$cur = $this->dict[$cur][$c]; //转到对应的位置<br />			if(isset($this->dict[$cur][$s[$i+1]])) {//检查下一个字符是否也能匹配，长度优先<br />				$i++;<br />				continue;<br />			}<br />			if(isset($this->dict[$cur]['acc'])) { //是叶子节点，单词匹配！<br />				if($buf != '') {<br />					$this->buffer[] = $buf;<br />					$buf = '';<br />				}<br />				if($this->savematch) $this->buffer[] = substr($s, $p, $i - $p + 1); //取出匹配位置和匹配的词<br /><br />				$ar = explode(',', $this->dict[$cur]['acc']);<br />				call_user_func_array( array($this, array_shift($ar)), $ar );<br /><br />				$p = $i + 1; //设置下一个回溯位置<br />				$cur = 0; //重置当前节点为根节点<br />			}<br />		} else { //不匹配<br />			$buf .= $s{$p}; //substr($s, $p, $i - $p + 1); //保存未匹配位置和未匹配的内容<br />			$cur = 0; //重置当前节点为根节点<br />			$i = $p; //把当前偏移设为回溯位置<br />			$p = $i + 1; //设置下一个回溯位置<br />		}<br />		$i++; //下一个字符<br />	}<br />	if(trim($buf, "\0")) $this->buffer[] = trim($buf, "\0");<br />  }<br /><br />  function __call($method, $param) {<br />	if($this->debug) printf("偏移:%d 回溯:%d\n", $this->input, $this->backtracking);<br /><br />  }<br />}<br />