Optimum algorithm to generate keys based on permutations - php

Question

In my application , I have few parameters (zone_id, startdate, enddate, brand, model) which I get from my UI form . Each of these parameters is an array containing 1 or more parameters .
My form parameters looks something like this :
Array
(
[sel_date_option] => today
[startdate] => 2011-09-19
[enddate] => 2011-09-19
[zone_id] => 1576,1562,1561
[model] => Array
(
[0] => A300
)
[brand] => Array
(
[0] => ACTS
)
)
Now , I want to generate keys which are combinations of these parameters . They would be something like :
[zone_id]_[model]_[brand]_[model]_[startdate]_[enddate]
This reflect all the possible arrangements of the above values .
For the above inputs, I should get the following keys :
1576_ACTS_A300_2011-09-19
1562_ACTS_A300_2011-09-19
1561_ACTS_A300_2011-09-19
Inside of giving the same startdate and enddate once can also enter a period like from 2011-09-19 to 2011-09-21.
What I am doing is I am using nested looping through all the parameter array and then creating a complex array of arrays something like the following :
Array
(
[0] => Array
(
[0] => 1576_DZ_A300
)
[1] => Array
(
[0] => 1576_DZ_A300
[1] => 1562_DZ_A300
)
[2] => Array
(
[0] => 1576_DZ_A300
[1] => 1562_DZ_A300
[2] => 1561_DZ_A300
)
[3] => Array
(
[0] => 1576_DZ_A300
[1] => 1562_DZ_A300
[2] => 1561_DZ_A300
[3] => 1563_DZ_A300
)
)
What I am doing is first I creating an array of all zones as :
Array
(
[0] => 1576
[1] => 1562
[2] => 1561
[3] => 1563
)
Then I am looping it using a nested loop for all the possible models and brands array like this :
function getInventoryData($criteria)
{
$index = "";
if($criteria['zone_id']!='')
{
$zone = explode(',', $criteria['zone_id']);
for($i=0;$i<count($zone);$i++)
{
$index[] .= $zone[$i];
}
echo '<pre>';print_r($index);exit;
}
if(!empty($criteria['model']))
{
foreach($index as $key=>$value)
{
foreach($criteria['model'] as $model)
{
$temparr[] = $index[$key].'_'.$model;
}
$index[$key] = $temparr;
}
}
Now , is there any other efficient method to achieve this ?
Moreover , there is another overhead associated with the above method :
While reading the generated keys , I have to loop through all the levels and in case of large sequence of data , the complexity can be really a matter of concern.

Answer 1

If I understand what you are trying to do correctly, this the most efficient method I can come up with for doing the above:
function getInventoryData ($arr) {
// Make sure all required keys are set
if (!isset($arr['zone_id'],$arr['model'],$arr['brand'],$arr['startdate'],$arr['enddate'])) return FALSE;
// Make a date string for the end of the keys
$dateStr = $arr['startdate'].(($arr['startdate'] == $arr['enddate']) ? '' : '_'.$arr['enddate']);
// Normalise the data
if (!count($arr['zone_id'] = array_unique(explode(',',$arr['zone_id']))) || !count($arr['brand'] = array_unique($arr['brand'])) || !count($arr['model'] = array_unique($arr['model']))) return FALSE;
// Get all possible permutations
$result = array();
foreach ($arr['zone_id'] as $zone) foreach ($arr['brand'] as $brand) foreach ($arr['model'] as $model) $result[] = "{$zone}_{$brand}_{$model}_{$dateStr}";
// Return the result
return $result;
}