$arr_str = array('qqqqqqqqqqqqqqqqqq 1', 'qwerty qwerty qwerty qwerty no');
foreach($arr_str as $index_str=>$str){
$split = str_split($str);
$abc_repeat = array();
foreach($split as $index_abc => $abc){
if(!trim($abc) ){
continue;
}
if(isset($abc_repeat[$abc])){
if(!isset($abc_repeat[$abc][1])){
$abc_repeat[$abc][1] = mt_rand(1, 9);
$arr_str[$index_str][$abc_repeat[$abc][0]] = $abc_repeat[$abc][1];
}
$arr_str[$index_str][$index_abc] = $abc_repeat[$abc][1];
continue;
}
$abc_repeat[$abc] = array($index_abc) ;
}
}
print_r($arr_str);