第4个回答 2012-10-09
<?php
$str = '90pil8a94riqp';
//$str = 'ababbdddddddccc128913a84uuuuiiia';
//$str = 'abcabc';
$result = array();
for($x=0;$x<=strlen($str);$x++){
preg_match_all('/(\w)(?:.*?)\1+/i',substr($str,$x,strlen($str)),$m);
if(isset($m[1][0]) && $m[1][0]){
$result[] = $m[1][0];
}
}
var_dump(array_unique($result));
?>