Online PHP editor | refs for 9ZDMF

<?php function checkCase($string) { $symMap = [ "." => ">", "," => "<" ]; foreach($symMap as $k => $v) $symMap[$v] = $k; $element = str_split($string); foreach($element as &$item) { if(in_array($item, $symMap)) $item = [$item, $symMap[$item]]; else $item = [strtolower($item), strtoupper($item)]; } $flags = array_fill(0, count($element), 0); $result = []; while(true) { $solution = ""; foreach(range(0, count($element) - 1) as $i) { $solution .= $element[$i][$flags[$i]]; } $isEnding = function() use(&$flags, $element) { foreach(range(0, count($flags) - 1) as $i) { if($flags[$i] < count($element[$i]) - 1) { $flags[$i]++; if($i > 0) foreach(range(0, $i - 1) as $j) $flags[$j] = 0; return false; } } return true; }; if(!$isEnding()) $result[] = $solution; else break; } return $result; } var_dump(checkCase("A.B")); var_dump(checkCase("ABCD"));