huahuibao/biz-hd/promote/classes/GuaGuaPrizeClass.php

<?php

namespace bizHd\promote\classes;

use Yii;
use bizHd\base\classes\BaseClass;

class GuaGuaPrizeClass extends BaseClass
{
	
	public static $baseFile = '\bizHd\promote\models\GuaGuaPrize';

	/*
	 * 计算中奖 ssh 2019.8.10
	 * [['id'=>1,'v'=>10],['id'=>2,'v'=>5,'id'=>0,'v'=>985]]
	 * id是奖品id，id=0表示没有中奖。v表示概率，加起来等于1000
	 * 返回示例：['id'=>1,'v'=>9]
	 */
	public static function getWinRand($proArr)
	{
		$result = array();
		foreach ($proArr as $key => $val) {
			$arr[$key] = $val['v'];
		}
		// 概率数组的总概率
		$proSum = array_sum($arr);
		asort($arr);
		// 概率数组循环
		foreach ($arr as $k => $v) {
			$randNum = mt_rand(1, $proSum);
			if ($randNum <= $v) {
				$result = $proArr[$k];
				break;
			} else {
				$proSum -= $v;
			}
		}
		return $result;
	}
	
}