配列、重複排除、統計関連、ちょっと難しい計算方法

<br /><meta charset="utf-8"><br /><?php <br />	$arra = array(<br />		0 => array(<br />			'id' => 0,<br />			'send_mobile'=> '13267310236',<br />			'c_content'=>'天气很热注意防暑'<br />		),<br />		1 => array(<br />			'id' => 1,<br />			'send_mobile'=> '13267310285',<br />			'c_content'=>'天气很热注意防暑'<br />		),<br />		2 => array(<br />			'id' => 2,<br />			'send_mobile'=> '13267310126',<br />			'c_content'=>'天气很热注意防暑'<br />		),<br />		3 => array(<br />			'id' => 3,<br />			'send_mobile'=> '13267310166',<br />			'c_content'=>'天气防暑'<br />		)<br />	);<br /><br />	$arrb = array();<br />	<br />	foreach ($arra as $v){<br />		$b = $v['c_content'];<br />		if(isset($arrb[$b])) <br />			$arrb[$b]['send_mobile'] .= ','.$v['send_mobile'];<br />		$arrb[$b] = isset($arrb[$b])?$arrb[$b]:$v;<br />	}<br />	<br />	$arrb = array_values($arrb);<br />	print_r($arrb);<br />?><br />