php简单中奖算法(实例)

function get_rand($proArr) {   $result = '';    //概率数组的总概率精度   $proSum = array_sum($proArr);    //概率数组循环   foreach ($proArr as $key => $proCur) {     $randNum = mt_rand(1, $proSum); if ($randNum <= $proCur) {   $result = $key;   break; } else {   $proSum -= $proCur; }}unset ($proArr);return $result;}$prize_arr = array('0' => array('id'=>1,'prize'=>'平板电脑','v'=>0.1),'1' => array('id'=>2,'prize'=>'数码相机','v'=>5),'2' => array('id'=>3,'prize'=>'音箱设备','v'=>10),'3' => array('id'=>4,'prize'=>'4G优盘','v'=>12),'4' => array('id'=>5,'prize'=>'10Q币','v'=>22),'5' => array('id'=>6,'prize'=>'下次没准就能中哦','v'=>50),);foreach ($prize_arr as $key => $val) {$arr[$val['id']] = $val['v'];}$rid = get_rand($arr); //根据概率获取奖项id$res['yes'] = $prize_arr[$rid-1]['prize']; //中奖项unset($prize_arr[$rid-1]); //将中奖项从数组中剔除，剩下未中奖项shuffle($prize_arr); //打乱数组顺序for($i=0;$i<count($prize_arr);$i++){$pr[] = $prize_arr[$i]['prize'];}$res['no'] = $pr;echo json_encode($res,JSON_UNESCAPED_UNICODE);