trie 的应用[连载1]

Trie 想来都是知道的，但将 trie 应用于 php 编程，所见资料却是很少的

先贴代码，以后逐次展开

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