如何在php中实现字符串匹配的暴力算法 - How to implement brute force algorithm for string matching in php?

How to implement brute force algorithm for string matching in php?

我有两个表，方案如下：

tb_keywords

id_keyword
keyword

tb_post

id_post
description

我想在php中实现sting匹配的暴力算法。如果描述与关键字匹配/相似，则此描述将插入tb_post。我试着让它发挥作用，但它不起作用。没有错误消息，只是给出了空白结果。

HTML

 <textarea type="text" class="form-control" name="description" id="description" placeholder="Description" required /></textarea>

PHP

$description = trim($_POST['description']);
$check = $db_con->prepare("SELECT * FROM  tb_keywords");
$check->execute();
$row=$check->fetch(PDO::FETCH_OBJ);
$positive = $row->keyword;
function brute_force($positive, $description)
{
    $n = strlen($description);
    $m = strlen($positive);
    for ($i = 0; i < $n-$m; $i++) {
        $j = 0;
        while ($j < $m && $description[$i+$j] == $positive[$j]) {
            $j++;
        }
        if ($j == $m) {
            return $i;
        }
        return -1;
    }
    $find[$i]=brute_force($positive, $description);
    $create=$db_con->prepare("INSERT INTO tb_post(description) VALUES(:description)");
    $create->bindParam(":description", $description);
    $create->execute();
    $row=$create->rowCount();
    if($row>0) {
        echo "success";
    } else {
        echo "fail";
    }
}

要查看文本中是否有特定单词，可以使用带有单词边界的正则表达式。

即

preg_match（"/''bPHP''b/"，"PHP中的regex"）#匹配中的单词"PHP"字符串

$description = trim($_POST['description']);
$check = $db_con->prepare("SELECT * FROM  tb_keywords");
$check->execute();
while($row = $check->fetch(PDO::FETCH_ASSOC)) {  
    $search = $row['keyword'];
    if (preg_match("/'b$search'b/", $description)) {  
        $create=$db_con->prepare("INSERT INTO tb_post(description) VALUES(:description)");
        $create->bindParam(":description", $description);
        $create->execute();
        $row=$create->rowCount();
        if($row>0) {
            echo "success";
        } else {
            echo "fail";
        }
    }
}