php年终抽奖-PHP源码

php年终抽奖-PHP源码

2.核心算法

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;
}