How to calculate title similarity ratio in php, calculate title in php_PHP tutorial

<&#63;php 
/*
 *
 * @param string $title_1 题目1
 * @param string $title_2 题目2
 * @return float $percent 相似百分比
 */
function title_similar($title_1,$title_2) {
  $title_1 = get_real_title($title_1);
  $title_2 = get_real_title($title_2);
  similar_text($title_1, $title_2, $percent);
  return $percent;
}
/**
 * php采集文章题目并去版权
 * @param string $html 需要采集的html源代码
 * @return string
 */
function get_real_title($str){
  $str = str_replace(array('-','—','|'),'_',$str);
  $splits = explode('_', $str);
  $l = 0;
  foreach ($splits as $tp){
    $len = strlen($tp);
    if ($l < $len){$l = $len;$tt = $tp;}
  }
  $tt = trim(htmlspecialchars($tt));
  return $tt;
}
//以下是测试
$title_1 = '代号PHPCMS V9产品正式发布公测版本';
$title_2 = 'PHPCMS再战江湖 V9产品正式发布公测版本';
$percent = title_similar($title_1,$title_2);
echo '相似百分比：'.$percent.'%';
echo "<br />\n";
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