<?php$a = 'abceee12345309878';$b = 'abceeew2345i09878fsfsfsfabceeewsfsdfsfsabceeew';$c = array();$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;?>

Totle time is 0.0012800693512 sabceee