php实现抽奖的简单概率算法

配置数组(v代表概率)

$prize_arr = array( '0' => array('id'=>1,'prize'=>'平板电脑','v'=>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), );

逻辑代码

foreach ($prize_arr as $key => $val) { 
    $arr[$val['id']] = $val['v']; 
} 
function get_rand($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; 
        } 
    }  
    return $result; 
}