An example of the maximum forward matching algorithm implemented in PHP

This article mainly introduces the maximum forward matching algorithm implemented in PHP, briefly describes the concept and principle of the maximum forward matching algorithm, and analyzes the related operating techniques of implementing and using the maximum forward matching algorithm in PHP in the form of examples. Friends in need can refer to the following

The examples in this article describe the maximum forward matching algorithm implemented in PHP. Share it with everyone for your reference. The details are as follows:

Forward maximum matching algorithm: Match several consecutive characters in the text to be segmented with the word list from left to right. If there is a match, , then a word is segmented. But there is a problem here: to achieve maximum matching, it is not possible to split the first match.

The function contains three parameters:

$query Query word
$dict Dictionary
$max_len Maximum length (the default value here is set to 15)

Dictionary example:

$dict = array(
  '脚本之家'=>'脚本之家',
  '脚本下载'=>'脚本下载',
  'JS编程'=>'JS编程'
);

Function definition:

/*
 * $query 查询词
 * $dict 词典
 * $max_len 最大长度
 */
function extractWords($query,$dict,$max_len=15){
    $feature = "";
    $slen=mb_strlen($query,'UTF8');
    $c_bg = 0;
    while($c_bg<$slen){
      $matched = false;
      $c_len =(($slen-$c_bg)>$max_len)?$max_len:($slen-$c_bg);
      $t_str = mb_substr($query, $c_bg,$c_len,&#39;UTF8&#39;);
      for($i=$c_len;$i>1;$i--){
        $ttts = mb_substr($t_str, 0,$i,&#39;UTF8&#39;);
          if(!empty($dict[$ttts])){
//          echo &#39;matched = &#39;.$ttts.PHP_EOL;
            $matched = true;
            $c_bg += $i;
            if(!empty($feature)){
              $feature.=",";
            }
            $feature.=$ttts;
            break;
          }
      }
      if(!$matched){
        $c_bg++;
      }
    }
    echo $feature.PHP_EOL;
}

Usage:

$query='欢迎访问脚本之家！脚本之家是国内专业的网站,提供各种脚本下载及JS、Python、php等编程资料';
extractWords($query,$dict);

Run result:

脚本之家,脚本之家,脚本下载

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