php中自动提取文章内容关键字seo优化网站的函数方法

利用discuz的基础条件实现文章内容自动提取关键字，进而优化网站内链的函数方法

方法一：此方法提取的关键字比较接近

function getkey($contents){  //
	$rows = strip_tags($contents);
	$arr = array(' ',' ',"\s", "\r\n", "\n", "\r", "\t", ">", "“", "”","<br />");
	$qc_rows = str_replace($arr, '', $rows);
	if(strlen($qc_rows)>2400){
		$qc_rows = substr($qc_rows, '0', '2400');
	}
	$data = @implode('', file("http://keyword.discuz.com/related_kw.html?title=$qc_rows&ics=gbk&ocs=gbk"));
	preg_match_all("/<kw>(.*)A\[(.*)\]\](.*)><\/kw>/",$data, $out, PREG_SET_ORDER);
	$key="";
	for($i=0;$i<5;$i++){
		$key=$key.$out[$i][2];
		if($out[$i][2])$key=$key.",";
	}
	return $key; 
}

方法二：此方法提取的关键字相对上面差一点点

function getkey($contents){ 
	$key = '';
	$rows = strip_tags($contents); 
	$arr = array(' ',' ',"\s", "\r\n", "\n", "\r", "\t", ">", "“", "”"); 
	$qc_rows = str_replace($arr, '', $rows); 
	if(strlen($qc_rows)>2400){ 
		$qc_rows = substr($qc_rows, '0', '2400'); 
	} 
	$data = @implode('', file("http://keyword.discuz.com/related_kw.html?title=$contents&ics=gbk&ocs=gbk")); 
	preg_match_all("/<kw>(.*)A\[(.*)\]\](.*)><\/kw>/",$data, $out, PREG_SET_ORDER); 
	for($i=0;$i<5;$i++){ 
		$key=$key.$out[$i][2]; 
		if($out[$i][2])$key=$key.","; 
	} 
	return $key; 
}