Detailed explanation of using PHP to find the longest common substring of two strings

How to find the longest common substring of two strings using PHP? This article mainly introduces the method of finding the longest common substring of two strings in PHP, involving the traversal, operation, judgment and other related operation skills of PHP strings and arrays. Friends in need can refer to it. I hope to be helpful.

The previous PHP method for solving the longest common substring problem is based on Java improvements. Here we look at another common substring algorithm.

The code is as follows:

<?php
$a = &#39;abceee12345309878&#39;;
$b = &#39;abceeew2345i09878fsfsfsfabceeewsfsdfsfsabceeew&#39;;
$c = array();
$lenht1 = strlen($a);
$lenth2 = strlen($b);
$startTime = microtime(true);
for ($i=0;$i<$lenht1;$i++) {
  for ($j=0;$j<$lenth2;$j++) {
    $n = ($i-1>=0 && $j-1>=0)?$c[$i-1][$j-1]:0;
    $n = ($a[$i] == $b[$j]) ? $n+1:0;
    $c[$i][$j] = $n;
  }
}
foreach ($c as $key=>$val) {
  $max = max($val);
  foreach ($val as $key1 =>$val1) {
    if ($val1 == $max && $max>0) {
      $cdStr[$max] = substr($b,$key1-$max+1,$max);
    }
  }
}
ksort($cdStr);
$endTime = microtime(true);
echo "Totle time is " . ($endTime - $startTime) . " s"."<br/>";
print_r(end($cdStr));
exit;
?>

Running results:

Totle time is 0.0012800693512 s
abceee

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