How can I add that subscribe to different segments?

I want to add my subscriber different segment by signup source. I create two segment in Mailchimp. How can I add that subscribe to different segments? I using API v2.

<?php
  include('MailChimp.class.php');

  $MailChimp = new DrewmMailChimp('ebae376c690e50d98ce069482eec5244-us8');
  $result = $MailChimp->call('lists/subscribe', array(
    'id'                => 'fde03148a4',
    'email'             => array( 'email' => $_POST['email'] ),
    'merge_vars'        => array(
    'MERGE2' => $_POST['name'] // MERGE name from list settings
    // there MERGE fields must be set if required in list settings
  ),
  'double_optin'      => true,
  'update_existing'   => false,
  'replace_interests' => false
));
if( $result === false ) {
    // response wasn't even json
}
else if( isset($result->status) && $result->status == 'error' ) {
    echo $result->status, $result->code, $result->name, $result->error;
}
?>

Answer

From the API Docs: you’ll need to add a groupings item to your merge_vars array. That should be an array of associative arrays with id and a groups array with the names of the groups you want to add the user to.

In v3, this is a good bit easier. There’s an interests object that just takes IDs and Booleans to determine if a user is added to or removed from a group.