function filterEquationBrackets($q)
{
$serializedEquation = serializeEquationToArray($q);
$equation = deserializeArrayToEquation($serializedEquation);
$filteredSerializedEquation = filterBracketBySerializedEquation($serializedEquation);
return deserializeArrayToEquation($filteredSerializedEquation);
}
function deserializeArrayToEquation($serializedEquation)
{
// init
$equation = '';
// process
foreach ($serializedEquation as $c) {
// recursive to get characters if $c is array
if (is_array($c)) {
$equation .= deserializeArrayToEquation($c);
continue;
}
// get character
$equation .= $c;
}
return $equation;
}