权重计算，用于返回一行文字在字典里哪一行的权重最高 变通一下亦可以用来做关键词匹配，分词等。

weight.php

<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +------------------------------------------------------------------------
//  Name       :   Weight Calculat                                         
//  Description:   provide weight calculation                              
//  Date       :   2013/12/16 08:51                                        
//  Authors    :   latel <latelx64@gmail.com>                              
// +------------------------------------------------------------------------
//

/*外部调用*/
$aItems = array(
    'chinaisbig',
    'whichisnot',
    'totalyrightforme',
);
$aTable = array(
    'china,is|small',
    'china,big|me',
    'china,is|big,which|not,me',
    'totaly|right,for,me',
);

$oWeight = new ttrie;
$oWeight->newItems($aItems);
$aResult = $oWeight->newTable($aTable);


/*类结构*/
class TTrie {
    protected $aDict = array(array());
    protected $aItems = array();
    protected $sLastRule;
    protected $aMatchs = array();
    protected $aShow = array();

	private function init() {
		//清空记录的匹配表和输出结果
		unset($this->aShow);
	}

	public function newItems($mItems) {
		//导入新的项目
		$this->aItems = (is_array($mItems))? $mItems: array($mItems);
		$this->init();
	}

	public function newTable(array $aTable) {
	        //导入新的对照表，并生成字典
	        foreach($aTable as $iTableKey=>$sTableLine) {
	            $aTableLine = explode(',', str_replace('|', ',', $sTableLine)); 
	            $setter = function($v, $k, $paraMeter) {
	                $k1 = $paraMeter[0]; $oWeight = $paraMeter[1];
	                $oWeight->genDict($v, $k1);
	            };
	            array_walk($aTableLine, $setter, array($iTableKey, $this));
	        }
	        $this->init();
	}

	public function getShow($sRule = 'max') {
    	//获取最终的显示结果
        if(empty($this->aItems) || empty($this->aDict))
            return array();
            if (empty($this->aShow) || $sRule != $this->sLastRule) 
	        return $this->genShow($sRule);
	    return $this->aShow;
	}

    public function genShow($sRule) {
        $aShow = array();
        $aMatchs = array();
		$getter = function($v, $k, $oWeight) use(&$aShow, &$aMatchs, $sRule) {
			$t = array_count_values($oWeight->matchWord($v));
		        $aMatchs[] = $t;
		        switch ($sRule) {
		            case 'max':
		                $aShow[$k] = array_keys($t, max($t));	
		                break;
		        }
		};
		array_walk($this->aItems, $getter, $this);
		$this->aShow = $aShow;
		$this->aMatchs = $aMatchs;
		return $aShow;
    }

    private function genDict($mWord, $iKey = '') {
        $iInsertPonit = count($this->aDict);
        $iCur = 0;
        foreach (str_split($mWord) as $iChar) {
            if (isset($this->aDict[$iCur][$iChar])) {
                $iCur = $this->aDict[$iCur][$iChar];
                continue;
            }
            $this->aDict[$iInsertPonit] = array();
            $this->aDict[$iCur][$iChar] = $iInsertPonit;
            $iCur = $iInsertPonit;
            $iInsertPonit++;
        }
        $this->aDict[$iCur]['acc'][] = $iKey; 
        
    }

        function matchWord($sLine) {
            $iCur = $iOffset = $iPosition = 0;
            $sLine .= "\0";
            $iLen = strlen($sLine);
            $aReturn = array();
            while($iOffset < $iLen) {
                $sChar = $sLine{$iOffset};
                if(isset($this->aDict[$iCur][$sChar])) {
                    $iCur = $this->aDict[$iCur][$sChar];
                    if(isset($this->aDict[$iCur]['acc'])) {
                        $aReturn = array_merge($aReturn, $this->aDict[$iCur]['acc']);

                        $iPosition = $iOffset + 1;
                        $iCur = 0;
                    }
                } else {
                    $iCur = 0;
                    $iOffset = $iPosition;
                    $iPosition = $iOffset + 1;
                }
                ++$iOffset;
            }
            return $aReturn;
        }
}

?>