PHP::Find a missing number

I came across this posting regarding missing number in sequence or random array: http://www.careercup.com/question?id=23092662

And the following source code is just a replica of the above. It works only if there is only one element is missing.

function getMissingNo($arr = array(), $size = 0) {
	$xord = 0; // full order element
	$xarr = 0; // my element
	// find the minimum and maximum values in the array 
	$min_val = $arr[0];
	$max_val = $arr[0];    
	for ($i = 1; $i < $size; ++$i){
		if ($arr[$i] > $max_val) {
			$max_val = $arr[$i];
		}        
		if ($arr[$i] < $min_val) {
			$min_val = $arr[$i];
		}
	}
	
	// find the XOR'ed value of all numbers from min_val to max_val inclusive
	for ($i = $min_val; $i <= $max_val; ++$i) {
		$xarr ^= $i;
	}
	for ($i = 0; $i < $size; ++$i){
		$xord ^= $arr[$i];
	}
	return ($xarr ^ $xord);
}
 
$arr = array(1, 2, 3, 4, 5, 6, 8);
$arr_len = count($arr);
$miss = getMissingNo($arr, $arr_len);
echo('missing number is: ' . $miss);

Getting a set of range records from Drupal 7 WebForm tables

Drupal 7 WebForm is a kind of a double edge sword just like any other Drupal contribution modules.

It creates a beautiful and fully functional web forms but makes customizing work a hard task. Of course it provides hooks but even those functions are not clearly defined some reasonings and other times it doesn’t provide things we need. I think the lack of support has a lot to do with the data structure of the WebForm; we already know it isn’t created by the best mind of structuring. I wouldn’t say this is a flaw but it is definitely not an advantage. Maybe that’s why there are some Drupal folks try to avoid WebForm. Maybe those flaws will go away when Drupal 8 rolls out; well, that’s beside of the point.

I used a WebForm because of the simplicity. Then later I faced a need bringing the data according to a predefined range. As you know, WebForm stores data vertically and bringing a record in horizontally isn’t a hard task if you’re familiar with SQL; however adding a range can be a challenge. Well, not quite if you understand WebForm is a content type. It means it is a node from Drupal point of view.

Here is an example:

/**
 * Queries and returns WebForm data with range
 * @param int $nid Webform Node Id
 * @param int $cid Webform field Id, the order of the webform field you created in webform_component table)
 * @return $result Returns WebForm data object or null if not found
 */
function get_results_with_range($nid, $cid) {
  // sub_data field collects other field information
  // so that group by sid is necessary
  // NOTE: sid is Serial Id of data
  $sql = "SELECT sd.sid, group_concat(IFNULL(sd.data, '') SEPARATOR ';') AS sub_data, rd.d_range, rd.d_order
	FROM {webform_submitted_data} AS sd
	JOIN (
		SELECT sid, data,
		CASE
			WHEN data >= 91 THEN 'Over 90'
			WHEN data >= 80 AND data <= 90 THEN '81 - 90'
			WHEN data >= 70 AND data <= 80 THEN '71 - 80'
			WHEN data >= 60 AND data <= 70 THEN '61 - 60'
			ELSE 'Under 60'
		END AS d_range,
		CASE
			WHEN data >= 91 THEN 1
			WHEN data >= 80 AND data <= 90 THEN 2
			WHEN data >= 70 AND data <= 80 THEN 3
			WHEN data >= 60 AND data <= 70 THEN 4
			ELSE 5
		END AS d_order
		FROM {webform_submitted_data}
		WHERE nid = :nid AND cid = :cid
		AND data != ''
	) AS rd
	ON sd.sid = rd.sid
	WHERE sd.nid = :nid
	GROUP BY sd.sid
	ORDER BY rd.d_order;";

	return db_query($sql, array(':nid' => $nid, ':cid' => $cid));
}

Displaying the results is pretty much intuitive. Here is an example:

/**
 * Getting html from WebForm data with range
 * @param object $result SQL results set
 * @return $html Returns html with a set of list
 */
function html_range_results($results) {
  $html = '';
  if ($results) {
    $old_range = '';
    $html .= '<ul>';
    foreach ($results as $row) {
      $sub_data = $row->sub_data;
      $new_range = $row->d_range;
      if (!empty($sub_data)) {
        // if range is different from the previous one
        if ($old_range != $new_range) {
          // taking care of html combination
          $html .= (empty($old_range) ? '' : '</ul>');
    	  // add a new range header
          $html .= '<h3>' . $new_range . '</h3>';
          $html .= '<ul>';
        }
        $data_array = explode(';', $sub_data);
        // let's say first field holds user name and we need to display it
        $user_name = $data_array[0];
        $html .= '<li>' . $user_name . '</li>';
      }
      $old_range = $new_range;
    }
    $html .= '</ul>';
  }
  return $html;
}