Online PHP editor | refs for RaWTN

<?php error_reporting(0); function f($s){while(!$a&&++$i<strlen($s))for($j=0;$b=substr($s,$j++,$i);)strpos($s,$b)==strrpos($s,$b)&&($a[]=$b);return$a;} echo "------\n"; var_dump(f("")); echo "\n"; // -> [""] var_dump(f("abcaa")); // -> ["b","c"] var_dump(f("rererere")); echo "\n"; // -> ["ererer"] var_dump(f("asdfasdfd")); echo "\n"; // -> ["fa","fd"] var_dump(f("ffffhhhhfffffhhhhhfffhhh")); echo "\n"; // -> ["hffff","fffff","hhhhh","hfffh"] var_dump(f("asdfdfasddfdfaddsasadsasadsddsddfdsasdf")); echo "\n"; // -> ["fas","fad","add","fds"] echo "------\n";