php数组的排重、累加、排序处理，50分全部送上！解决方法

php数组的排重、累加、排序处理，50分全部送上！

PHP code

$t = array (
  array(
  'cid'  => 123,
  'hits' => 200,
  ),
  array(
  'cid'  => 456,
  'hits' => 100,
  ),
  array(
  'cid'  => 789,
  'hits' => 300,
  ),
  array(
  'cid'  => 123,
  'hits' => 600,
  ),
  array(
  'cid'  => 456,
  'hits' => 500,
  ),
  array(
  'cid'  => 789,
  'hits' => 700,
  ),
);

数组中有很多值是重复的cid，他们对应的hits不一样，希望进行cid排重，hits累加，再按照hits倒序排列，输出结果如下：

PHP code

$t = array (
  array(
  'cid'  => 789,
  'hits' => 1000,
  ),
  array(
  'cid'  => 123,
  'hits' => 800,
  ),
  array(
  'cid'  => 456,
  'hits' => 600,
  ),
);

多谢大家了！

------解决方案--------------------

PHP code

foreach($t as $v){
     if(!$ar[$v['cid']])
             $ar[$v['cid']]=$v;
     else
             $ar[$v['cid']]['hits']+=$v['hits'];     
}

foreach($ar as $v) $k[]=$v[hits];
array_multisort($k,SORT_DESC,$ar);
print_r($ar);

------解决方案--------------------

PHP code

$t = array (
  array(
  'cid'  => 123,
  'hits' => 200,
  ),
  array(
  'cid'  => 456,
  'hits' => 100,
  ),
  array(
  'cid'  => 789,
  'hits' => 300,
  ),
  array(
  'cid'  => 123,
  'hits' => 600,
  ),
  array(
  'cid'  => 456,
  'hits' => 500,
  ),
  array(
  'cid'  => 789,
  'hits' => 700,
  ),
);

$r = array();
foreach($t as $v) {
  if(!isset($r[$v['cid']])) $r[$v['cid']] = $v;
  else $r[$v['cid']]['hits'] += $v['hits'];
}

usort($r, create_function('$a,$b', 'return $a["hits"]